Effect of Spodic Derived Fill Materials on Growth and Establishment of St. Augustinegrass

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Title:
Effect of Spodic Derived Fill Materials on Growth and Establishment of St. Augustinegrass
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1 online resource (134 p.)
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english
Creator:
Mclean, Drew C
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University of Florida
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Gainesville, Fla.
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Degree:
Master's ( M.S.)
Degree Grantor:
University of Florida
Degree Disciplines:
Soil and Water Science
Committee Chair:
Shober, Amy L
Committee Co-Chair:
Ellis, Larry
Committee Members:
Harris, Willie G
Cole, Dara

Subjects

Subjects / Keywords:
bh -- dps -- leaching -- phosphorus -- psr -- turfgrass
Soil and Water Science -- Dissertations, Academic -- UF
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Soil and Water Science thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Turfgrass represents a dominate component of urban landscapes and require water and fertilizer inputs to produce functioning healthy systems. Stenotaphrum secundatum Walt. Kuntze (st. augustinegrass, STA) is a widely used turfgrass choice in urban settings throughout Florida. Fill materials used in residential construction can have varying physical and chemical properties which have the potential to negatively impact the establishment of turfgrass in urban settings. The phosphorus (P) sorption capacity of different fill materials can affect P leaching from urban areas. Research has shown that P retention capacity and P saturation status of soils, mainly the amounts of aluminum and iron in relation to P, greatly affect the potential for soils to leach P. Research has also shown different P saturation measurements like the P saturation ratio (PSR), degree of P saturation (DPS), and soil P storage capacity (SPSC) have been able to accurately identify the P leaching potential of acidic soils in agricultural systems. Over the last 20 to 30 years, there has been an increase of fresh surface water quality issues that have been linked to excess P inputs from urban areas. In response, Florida adopted the urban turf rule which limits the amount of P allowed to be applied to turfgrass in urban settings. It is unknown if certain chemical properties of soil fill materials that are related to P retention will effect P bioavailability to turfgrass and influence P leaching from urban settings. The objectives of this study were to: 1) determine the response and quality of STA grown on spodic (Bh horizon) derived fill materials and 2) to quantify the leaching of P from Bh and non-Bh fill soils. We evaluated the growth and quality of STA sod establishment in PVC columns containing five soil fill materials (three Bh and two non-Bh) over a 9- and 27-week period. Phosphorus (molybdate reactive, dissolved reactive orthophosphate, and total dissolved) leaching losses from the soil columns were also evaluated. Soil physical and chemical properties, turfgrass biomass, quality, and tissue nutrient contents; and leachate volume, molybdate reactive P, dissolved reactive orthophosphate, and total dissolved P were assessed periodically throughout the study period. Results from our study show that Bh horizon soil treatments did not negatively affect the establishment or bioavailability of P to STA. In fact, turfgrass quality ratings and shoot count measurements of STA grown on some Bh horizons were significantly higher than compared to the uncoated sands in of the E horizon soil. Results from this study indicate that turfgrass was able to effectively uptake stored P from the Bh horizons during establishment periods. Results from our study also indicate that STA is able to establish on low P soils, even without significant application of P fertilizer. Phosphorus saturation measurements (PSR, DPS, and SPSC) were generally able to predict soil treatments with high leaching P potentials and soils with high concentrations of water soluble P. However, one Bh horizon (Myakka-Bh1) with significantly lower PSR and DPS values and positive SPSC values leached significantly higher P concentrations and contained similar soil water soluble P values to the Paola-Bw soil that had significantly higher PSR and DPS values and negative SPSC values. Data obtained from our study supports the idea that different soil types should have different PSR and DPS threshold values. Results from this study also indicate that, even with as little as 0.059 g·m-2 P fertilizer applied, some Bh horizon fill materials with PSR and DPS values well below established change points still leach P concentrations that may be of environmental concern.
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In the series University of Florida Digital Collections.
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Includes vita.
Bibliography:
Includes bibliographical references.
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Description based on online resource; title from PDF title page.
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This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Drew C Mclean.
Thesis:
Thesis (M.S.)--University of Florida, 2012.
Local:
Adviser: Shober, Amy L.
Local:
Co-adviser: Ellis, Larry.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2014-08-31

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UFE0044673:00001


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1 EFFECT OF SPODIC DER IVED FILL MATERIALS ON GROWTH AND ESTABLISHMENT OF ST. AUGUSTINEGRASS By DREW CAMERON MCLEAN A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2012

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2 2012 Drew Cameron McLean

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3 To my friends and family

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4 ACKNOWLEDGMENTS I would like to thank my advisor, Dr. Amy Shober and my co advisor, Dr. Rex Ellis for their endless guidance and support throughout my entire graduate program I would also like to thank my other committee members Dr. Willie Harris and Dr. Dara Park for t heir inputs and suggestions on my thesis from start to finish Next, I would like to say thank you to my family and friends who provided me with the much needed support throughout the last two and a half years. Last, but not least I would like to say a spe cial help with setting up the experiment and data collection.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ ...... 4 LIST OF TABLES ................................ ................................ ................................ ................ 7 LIST OF FIGURE S ................................ ................................ ................................ .............. 8 ABSTRACT ................................ ................................ ................................ ........................ 11 CHAPTER 1 LITERATURE REVIEW AND RESEARCH OBJECTIVES ................................ ....... 14 St. Augustinegrass Origin and Morphological Characteri stics ................................ .. 14 Urban Topsoil Fill ................................ ................................ ................................ ........ 15 Occurrence of Spodosols in Florida ................................ ................................ ........... 15 Eutrophication and Nutrient Management Strategies ................................ ............... 17 Phosphorus Retention in Soils ................................ ................................ ................... 20 Phosphorus Retention in Florida Soils ................................ ................................ ....... 22 Measurements of Soil Phosphorus Retention Capacity ................................ ............ 23 Phosphorus Leaching from Turfgrass Systems ................................ ......................... 25 Phosphorus Fertilizer and Soil Effects on Turfgrass Quality ................................ ..... 27 Current Situation and Research Objectives ................................ .............................. 29 2 EFFECT OF SPODIC FILL MATERIALS ON THE GROWTH AND ESTABLISHMENT OF ST. AUGUSTINEGRASS ................................ ..................... 31 Introduction ................................ ................................ ................................ ................. 31 Materials and Methods ................................ ................................ ............................... 35 S ite L ocations and Soil Sampling ................................ ................................ ........ 35 Experimental Design ................................ ................................ ............................ 35 Irrigation and Fertilizer Application ................................ ................................ ...... 36 Pesticide Applications ................................ ................................ .......................... 38 Characterization of Soil Properties ................................ ................................ ...... 39 Turfgrass Quality and Chlorophyll Content (SPAD) ................................ ........... 40 Turfgrass Biomass ................................ ................................ ............................... 40 Tissue Nutrient Content ................................ ................................ ....................... 41 Data Analysis ................................ ................................ ................................ ....... 42 Results ................................ ................................ ................................ ........................ 43 Soil Characterization ................................ ................................ ............................ 43 Turfgrass Quality Ratings and Chlorophyll Content (SPAD) .............................. 46 Turfgrass Biomass ................................ ................................ ............................... 48 Tissue Nutrient Content ................................ ................................ ....................... 49 Disc ussion ................................ ................................ ................................ ................... 52

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6 3 LEACHING OF PHOSPHORUS FROM ST. AUGUSTINEGRASS ESTABLISHED ON SPODIC FILL MATERIALS ................................ ....................... 70 Introduction ................................ ................................ ................................ ................. 70 Materials and Methods ................................ ................................ ............................... 73 S ite L ocations and Soil Sampling ................................ ................................ ........ 73 Experimental Design ................................ ................................ ............................ 73 Irrigation and Fertilizer Application ................................ ................................ ...... 75 Soil Characterization ................................ ................................ ............................ 76 Leacha te Collection and Analysis ................................ ................................ ....... 78 Turfgrass Root Biomass ................................ ................................ ...................... 79 Data Analysis ................................ ................................ ................................ ....... 80 Results ................................ ................................ ................................ ........................ 81 Soil Properties ................................ ................................ ................................ ...... 81 Leachate Drainage Depths ................................ ................................ .................. 84 Molybdate Reactive Phosphorus in Leachate ................................ ..................... 85 Dissolved Reactive Orthophosphate Filtered in Leachate ................................ 87 Total Dissolved Phosphorus Filtered in Leachate ................................ .............. 89 Turfgrass Root Biomass ................................ ................................ ...................... 90 Discussion ................................ ................................ ................................ ................... 90 4 CONCLUSION ................................ ................................ ................................ .......... 113 APPENDIX: CHEMICAL PROPERTIES AND PHOSPHORUS SORPTION CAPACITY OF SELECTED FLORIDA SPODIC HORIZONS ................................ ....... 115 Soil Sample Collection ................................ ................................ .............................. 115 Soil Characterization ................................ ................................ ................................ 116 LIST OF REFERENCES ................................ ................................ ................................ 124 BIOGRAPHICAL SKETCH ................................ ................................ .............................. 134

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7 LIST OF TABLES Table page 2 1 Irrigation schedule for st. augustinegrass establishment in soil columns in a production house in Wimauma, FL. ................................ ................................ ....... 59 2 2 Mean initial bulk density of Florida fill materials used in soil columns to evaluate st. augustinegrass growth and quality response to soil properties. ....... 59 2 3 Mean selected chemical properties of Florida soil fill materials used in a column study to evaluate st. augustinegrass growth and quality response to soil properti es at 0, 9, and 27 weeks after planting. ................................ ............. 60 2 4 Mean biomass of clippings, pelts, and roots of st. augustinegrass grown on differe nt Florida soil fill materials in a soil column study. ................................ ...... 61 2 5 Mean total nutrient content of clippings from st. augustinegrass grown on five different Florida soil fill materials collected from 0 to 9 and 10 to 27 weeks after planting. ................................ ................................ ................................ .......... 61 2 6 Mean nutrient concentrations of clippings from st. augustinegrass grown on five different Florida soil fill materials collected from 0 to 9 and 10 to 27 weeks after planting. ................................ ................................ .............................. 62 2 7 Mean total nutrient content of pelts from st. augustinegrass grown on five different Florida soil fill materials collected at the 9 and 27 week harvest date. ................................ ................................ ................................ ........................ 62 2 8 Mean total nutrient content of roots from st. augustinegrass grown on five different Florida soil fill materials collected at the 9 and 27 weeks after planting. ................................ ................................ ................................ .................. 63 3 1 Mean selected chemical properties of Florida soil fill materials used in a column study to evaluate the effect of soil properties on phosphorus leaching from st. augustinegrass at 0, 9, and 27 weeks after planting. .............................. 96 3 2 Mean biomass of roots of st. augustinegrass grown on different Florida soil fill materials in a soil column conducted in Wimauma, FL. ................................ ... 97 A 1 Selected chemical properties and phospho rus measurements of 30 Bh horizon samples collected from five locations throughout Florida. ..................... 119 A 2 Mehlich 3 nutrients and phosph orus saturation measurements of 30 Bh horizon samples collected from five locations throughout Florida. ..................... 120

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8 LIST OF FIGURES Figure page 2 1 Mean weekly soil volumetric water content of Florida soil fill materials used in a column study to evaluate st. augustinegrass growth and quality response to soil properties collecte d over 9 and 27 week establishment study periods. Values within the establishment period with the same letter are not significantly different at P test. ................................ ................................ ................................ ......................... 64 2 2 Mean weekly visual quality ratings from 0 to 9 weeks after planting of st. augustinegrass grown in Florida soil fill materials. Visual ratings use a scale from 1 to 9, with 1= dead, brown turf; 6= minimally acceptable turf; and 9= highest quality turf. No significant difference ( P > 0.05) was observed between soil treatments during the first 9 weeks after planting. ........................... 65 2 3 Mean visual quality ratings of st. augustinegrass grown in Florida soil fill materials at 11, 12, 15, 17, 25, and 27 weeks after planting (WAP) Visual ratings use a scale from 1 to 9, with 1= dead, brown turf; 6= minimally acceptable turf; and 9= highest quality turf. Values within the same sampling date with the same letter are not significantly different at P < 0.05 using ficant difference test. ................................ .......................... 66 2 4 Mean SPAD meter readings for st. augustinegrass grown in Florida soil fill materials at 5, 8, and 9 weeks after planting (WAP). Values within the same sampling date with the same letter are not significantly different at P < 0.05 ................................ ................ 67 2 5 Mean SPAD meter readings st. augustinegrass grown in Florida soil fill materials during a 27 week establishment study. Values with the same letter are not significantly different at P < difference test. ................................ ................................ ................................ ........ 68 2 6 Mean shoot counts of st. augustinegrass grown in Florida soil fi ll materials at 9 and 27 weeks after planting. Values within the same harvest date with the same letter are not significantly different at P significant difference test. ................................ ................................ ...................... 69 3 1 Temporal trends in mean weekly drainage collected soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials. Irrigation de pths are shown on the top graph with the drainage to irrigation ratios shown in the middle graph. Irrigation depths for week six are missing due to a power outage to automatic timer that resulted in an unknown amount of water applied. ................................ ................................ ........ 98 3 2 Mean drainage depths of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different so il fill

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9 materials at 4, 5, 9, 12, 13, and 14 weeks after planting (WAP). Values within the same collection date with the same letter are not significantly different at P ................................ 99 3 3 Mean drainage depths of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials at 15, 17, 23, 24, 25, and 26 weeks after planting (WAP). Values within the same collection da te with the same letter are not significantly different at P ............. 100 3 4 Te mporal trends in mean weekly molybdate reactive phosphorus concentrations in leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials. ................................ ................................ ................................ .............. 101 3 5 Mean molybdate reactive phosphorus concentrations of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on d ifferent soil fill materials at 2, 4, 9, 14, and 23 weeks after planting (WAP). Values within the same collection date with the same letter are not significantly different at P difference test. ................................ ................................ ................................ ...... 102 3 6 Temporal trends in mean molybdate reactive phosphorus loads in leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials. ................................ 103 3 7 Mean molybdate reactive phosphorus loads of leachate collect ed from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials at 2, 4, 9, 14, 21, and 23 weeks after planting. Values within the same collection date with the same letter are not significantly dif ferent at P difference test. ................................ ................................ ................................ ...... 104 3 8 Mean cumulative molybdate reactive phosphorus load s in leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials during the 9 and 27 week establishment periods. Values within the same collection period with the same letter ar e not significantly different at P significant difference test. ................................ ................................ .................... 105 3 9 Temporal trends in mean weekly dissolved reactive orthophosphate concentrations in leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials. ................................ ................................ ................................ .............. 106 3 10 Mean dissolved reactive orthophosphate concentrations of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials at 2, 3, 4, 5, 6, and 9 weeks after

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10 planting (WAP). Values within the same collection date with the same letter are not significantly different at P difference test. ................................ ................................ ................................ ...... 107 3 11 Mean dissolved reactive orthophosphate loads of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials at 2, 3, 4, 5, 6, and 9 weeks after planting. Values within the same collection date with the same letter are not significantly different at P test. ................................ ................................ ................................ ....................... 108 3 12 Temporal trends in mean dissolved reactive orthophosphate loads of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials. ................................ 109 3 13 Mean cumulative dissolved reactive orthophosphate loads in leachate collected from soil coulmns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials during the 9 and 27 week establishment periods. Values within the same collection period with the same letter are not significantly different at P honestly significant difference test. ................................ ................................ ...... 110 3 14 Mean total dissolved phosph orus concentrations of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials during the first four weeks after planting. Values within the same collection period with the s ame letter are not significantly different at P test. ................................ ................................ ................................ ....................... 111 3 1 5 Mean total dissolved phosphorus loads of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials during the first four weeks after planting. Values within the same collection period with the same letter are not significantly different at P test. ................................ ................................ ................................ ....................... 112 A 1 Geographic locations of 30 Bh horizon samples collected for the characterization of various chemical properties. ................................ ................. 123

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11 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science EFFECT OF SPODIC DER IVED FILL MATERIALS ON GROWTH AND ESTABLISHMENT OF ST. AUGUSTINEGRASS By D re w C ameron M cLean August 2012 Chair: Amy Shober Cochair: Rex Ellis Major: Soil and Water Science Turfgrass represents a dominate component of urban landscapes and require water and fertilizer inputs to produce functioning healthy systems. Stenot aphrum sec u ndatum Walt. Kuntze ( s t. a ugustinegrass, STA) is a widely used turfgrass choice in urban settings throughout Florida. Fill material s used in residential construction can have varying physical and chemical properties which have the potential to negatively impact the establishment of turfgrass in urban settings. The phosphorus (P) sorption capacity of different fill materials can affect P leaching from urban areas. Research has shown that P retention capacity and P satu ration status of soils, mainly the amounts of aluminum and iron in relation to P, greatly affect the potential for soils to leach P. Research has also shown different P saturation measurements like the P saturation ratio (PSR), degree of P saturation (DPS) and soil P storage capacity (SPSC) have been able to accurately identify the P leaching potential of acidic soils in agricultural systems. Over the last 20 to 30 years, there has been an increase of fresh surface water quality issues that have been linke d to excess P inputs from urban areas. In response, Florida adopted the urban turf rule which limits the amount of P allowed to be

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12 applied to turfgrass in urban settings. It is unknown if certain chemical properties of soil fill materials that are related to P retention will effect P bioavailability to turfgrass and influence P leaching from urban settings. The objectives of this study were to: 1) d etermine the response and quality of STA grown on spodic (Bh horizon) derived fill material s and 2) to quantif y the leaching of P from Bh and non Bh fill soils. We evaluated the growth and quality of STA sod establishment in PVC columns containing five soil fill materials (three Bh and two non Bh) over a 9 and 27 week period. Phosphorus (molybdate reactive, disso lved reactive orthophosphate, and total dissolved) leaching losses from the soil columns were also evaluated. Soil physical and chemical properties, turfgrass biomass, quality, and tissue nutrient contents; and leachate volume, molybdate reactive P, dissol ved reactive orthophosphate, and total dissolved P were assessed periodically throughout the study period. Results from our study show that Bh horizon soil treatments did not negatively affect the establishment or bioavailability of P to STA. In fact, tur fgrass quality ratings and shoot count measurements of STA grown on some Bh horizons were significantly higher than compared to the uncoated sands in of the E horizon soil. Results from this study indicate that turfgrass was able to effective ly uptake stor ed P from the Bh horizons during establishment periods. Results from our study also indicate that STA is able to establish on low P soils even without significant application of P fertilizer. Phosphorus saturation measurements (PSR, DPS, and SPSC) were ge nerally able to predict soil treatments with high leaching P potentials and soils with high concentrations of water soluble P. However, one Bh horizon (Myakka Bh1) with significantly lower PSR and DPS values and positive SPSC values leached significantly

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13 h igher P concentrations and contain ed similar soil water soluble P values to the Paola Bw soil that had significantly higher PSR and DPS values and negative SPSC values. Data obtained from our study supports the idea that different soil types should have di fferent PSR and DPS threshold values. Results from this study also indicate that, even with as little as 0.059 g m 2 P fertilizer applied some Bh horizon fill materials with PSR and DPS values well below established change points still leach P concentrations that may be of environmental concern.

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14 CHAPTER 1 LITERATURE REVIEW AND RESEARCH OBJECTI VE S St. Augustinegrass Orig in and Morphological Characteristics Stenotaphrum secundatum Walt. Kuntze ( s t. a ugustinegrass, STA) is native to the Gulf of Mexico region, the West Indies, and parts of Western Africa ( Trenholm et al., 2011) On the east coast of the United States, STA is planted from Florida to the Carolinas because it is best adapted to subtropical climates. St. a ugustinegrass is a stoloniferous grass species that roots at the nodes. This coarse textured turfgrass has compre ssed leaf sheaths, generally folded leaf blades, and rounded leaf tips (U.S. Department of Agriculture 2010) It has moderate shade tolerance, low drought tolerance and can be best establish ed in soils with a pH range of 4.8 to 7.5 (Trenholm et al. 2006; U.S. Department of Agriculture, 2010 ) St. augustinegrass develops roots within the upper 15.2 to 30.5 cm of the soil and does not tolerate compacte d or waterlogged soils ( U.S. Department of Agriculture, 2010) St. augustinegrass has a green to blue green colored dense turf and can produce a thick thatch layer under high fertilization and irrigation regimes ( Trenholm et al ., 2006) Like most other warm season grasses, STA goes into winter dormancy during colder months, turning a brown or tan color. St. augustinegrass is the most popular turfgrass choice for lawns th roughout the southeastern United States, covering roughly 40% of the approximately 2 million h a of home lawn turf grass in the state of Florida (L iu et al., 2008; Trenholm et al., 2006) Haydu et al. (2005) reported that STA represented 64% of the total sod production for STA that are available for lawn use in Florida. The cultivars have a range of leaf

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15 textures, varying toleranc es to environmental stresses, and different susceptibilities to pests ( Trenholm et al., 2011) is a popular coarse textured cultivar that was released in 1973 by the University of Florida and Texas A & M Univer sity. Despite its poor cold and shade tolerance (relative to other STA STA remains the most widely produced and used STA cultivar for Florida lawns in urban settings ( Trenholm et al., 2011) Urban Tops oil Fill Human construction activities that occur during the urbanization of rural areas often result in the disturbance and redistribution of native soils. During the development of residential communities the native vegetation and topsoil are often remov ed to prepare the soil for building ( Lehmann and Stahr, 2007; Scharenbroch et al., 2005; Shober and Toor, 2009) After removal of vegetation and topsoil, the addition of fill material is sometimes required to achieve a level grade. This fill material usually consists of soil that was removed from nearby areas during the construction of storm water retention ponds or soil that was hauled in from other locations, such as a borrow pit. Fill material used in construction can have varying physical and chemical properties due to the mixing of different s oil horizons ( Pouyat et al., 2007; Scharenbroch et al., 2005; Short et al., 1986) Occurrence of Spodosols in Florida Spodosols are most prevalent in cool, humid or perhumid climates; however they are widely distributed throughout the southeastern USA, occurring mainly in flatwoods ecosystems of the Coastal Plains (U.S. Department of Agriculture Natural Resources Conservation Service, 2012) Spodosols are a dominant soil order in Florida ; covering ap proximately 3.4 million ha (approximately 27% of soil coverage ) throughout the state

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16 ( Carlise and Brown, 1982; Coll ins, 2010; Stone et al. 1993) I n Florida Spodosols are typically characterized by sandy soil textures, fluctuating water tables, and the presence of a subsurface spodic (Bh) horizon ( Harris et al., 1995) The main accepted theory of Bh horizon formation and Spodosol genesis, involves mobilization and complexation of metals by di ssolved organic carbon (DOC) ( Deconinck 198 0) Dissolved organic carbon is released into the soil profile during microbial mediated litter decay Once released into the soil environment, DOC molecules promote the weathering of various soil minerals and metal oxide coatings on sand grains ( Harris et al., 1995) As these soil minerals and metal oxide coatings weat her, they release ions [ e.g., aluminum (Al), iron (Fe), etc. ] into the soil solution. The DOC molecules, which possess a net negative charge, attract cations that were released when soil minerals were weathered. Larger valence cations, like Al 3+ and Fe 3+ are strongly attracted to the DOC molecules and become chelated or complexed. As the DOC molecules move downward through the soil profile, they complex additional metal cations, reducing the net negative charge on the DOC molecule. When the net negative ch arge on the DOC molecules are reduced enough for Van der Waals forces to overcome the force of repulsion between the DOC molecules, precipitation or flocculation can occur ( Deconinck 1980) This process of eluviation leaves uncoated sand grains expo sed in a light color ed E horizon which overlays the dark colored layer of illuvation (Bh horizon) that is enriched with organo metal compounds Spodic horizons i n Florida are typically acidic and contain large amounts of organic carbon (C) and Al oxides as a result of podzolization processes

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17 Since Spodosols are one of the most widely distributed soil orders in Florida, it is likely that some of the fill material imported into construction areas will contain Bh horizon subsurface soils. Misinterpretatio n of the quality of this dark colored acidic soil may also lead to application of Bh horizon soil as a topsoil. It is possible that the acidic nature and accumulation of metal oxides in Florida Bh horizons may have direct affects on nutrient fate and bioav ailability. Eutrophication and Nutrient Management Strategies Many studies link the degradation of surface water quality (e.g. harmful algal blooms, eutrophication, and dead zones) to the discharge of nutrients from point and non point sources (Anderson et al., 2002; Riegman, 1995; Sharpley et al., 2003; Smith, 1983 ) In particular, phosphorus (P) has been shown to be the main limiting nutrient for algal and aquatic weed growth in fresh surface water bodies (Correll, 1 998; Sharpley et al., 2003 ) Excess additions of P into freshwater bodies can result in large algal blooms that restrict recreational an d drinking water usage and can cause oxygen shortages to other aquatic biota ( Sharpley et al. 2003) In Florida, the main strategies for controlling nutrient losses from lawns and landscapes are best management practices (BMPs) and controlling fertilizer applications in urban areas. In 2002, the Florida Department of Environmental Protection (FDEP) published the Florida Green Industries BMP Manual, which provided BMPs for turfgrass and landscape maintenance professionals to use statewide ( Hartman et al., 2008) This manual followed the Professional Lawn Care Association of guide. Prior to 2002, only two local governments, St. Johns County and the Village of Wellington, had placed restrictions on the use of fertilizers ( Hartman et al., 2008) However both of these fertilizer restrictions were tailored to

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18 improved water quality by decreasing nutrient runoff from ranching practices and did not focus on nutrient runoff from urban areas. Ordinance Language for the Protection of Wate r Quality and Quantity Using Florida land development regulations ( Hartman et al., 2008) This model ordinance combined Florida Friendly Landscaping concepts with BMPs that were supported by University of F lorida Institute of Food and Agricultural Sciences ( UF IFAS ) This model ordinance mainly addressed site planning techniques and only briefly addressed fertilizer use. In 2007, the Florida Legislature appointed the Florida Department of Agriculture and C onsumer Services (FDACS) to create the Florida Consumer Fertilizer Task Force ( Hartman et al., 2008) This task force helped develop recommendations for statewide policies and programs regarding consumer fertilizer use. As state agencies worked to implement plans for the statewide protection of surface and groundwater, many local governments began to implement their own preventive measures via county and city wide fertilizer ordinances. By the end of 2007, the city of Sanibel Island, Sarasota County, the city of Sarasota, the city of Cape Coral, the city of North Port, and the city of Naples had adopted local fertilizer ordinances ( Hartman et al., 2008) Numerous state statutes were developed that encouraged communities and loca l governments to adapt various Florida Friendly ordinances. As enacted, Section 403.9337 of the Florida Sta tutes encouraged county and municipal govern ments to adopt and enforce the model o rdinance for Florida Friendly Fertilizer Use on Urban Landscapes ( or an equivalent ) as a mechanism for protecting local surface water and

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19 groundwater quality ( Florida Department of Environmental Protection 2010) Local governments are allowed to adopt more stringent standards then outlined in the model ordinance if it demonstrated that: a) additional or more stringent standards were necessary to adequately address fertilizer contributions to nutrient loading in water bodies; and b) it had considered all relevant scientific information, including in put from the FDEP, FDACS, and the UF IFAS (Florida Department of Environmental Protection, 2010) Many of these local ordinances include d preventive measures that were more stringent than guidelines in the model ordinance. For example, these local ordinances applications during certa in months of the year ( Hartman et al ., 200 8) Other differences in local ordinances, as compared to the model ordinance, were related to the amount of n itrogen (N) and P applied in a single application and annually, the distance from water allowances for turfgrass establishment periods ( Hartman et al., 2008) In 2008, the newly appointed FDACS fertilizer task force enacted the urban turf ( Florida Department of Agriculture and Consumer Services, 2010; Trenholm, 2010 ) The urban turf fertilizer rule changed the labeling requirements for turf fertilizers and limited fertilizer application rates of N and P in turfgrass areas. The urban turf fertilizer rule allows for a one time starter P application within one year of planting new sod. This starter fertilizer can be applied at a P rate of 2.15 g m 2 P Subsequent P applications are limited to 0.54 g m 2 P per application, with no more than 1. 07 g m 2 P applied annually (Florida Department of Agriculture and

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20 Consumer Services, 2010; Trenholm, 2010 ) Additional P fertilizer is permitted provided soil testing indicates the need for P. However, standard agronomic soil tests [e.g., Mehlich 1 (M1) or Mehlich 3 (M3)] do not account for the P retention capacity of the soils and may overestimate the pool of available P fo allowing for fertilizer applications in excess of the urban fertilizer rules annual limit, but the soil may not have any low remaining P sorption capacity so added P could easily be lost to the surrounding environment. On the other end, a standard soil P test may show soil may have high levels of P associated with Al or Fe that is not read ily available to the turfgrass, which may result in unhealthy turfgrass growth and development. Therefore, it is important to understand P retention in soils and considered adopting soil measurements that account for P retention in soils. Phosphorus Retent ion in Soils Phosphorus exists in many different chemical forms and species (i.e., H 3 PO 4 H 2 PO 4 HPO 4 2 and PO 4 3 ) in the soil solution environment (Brady and Weil 2002) The presence of these P species can be directly related to soil pH, which in turn, has a direct effect on the amount of plant available P. In acid soils (pH < 5.5), P ions react with F e and Al oxides to form surface complexes or react with dissolved Fe 3+ and Al 3+ ions to form insoluble hydroxyl phosphate precipitates ( Brady and Weil, 2002 ) When soil pH is neutral to alkaline, P reacts with calcium and m agnesium ions to form precipitates or is absorbed to surfaces of CaCO 3 ( Havlin et al., 2005; Lindsay, 2001) This leaves a small pH range (6.5 to 7.0) for the dominance of the optimal plant available P ions, H 2 PO 4 and HPO 4 2 ( Havlin et al., 2005) Phosphorus adsorption is the process by which

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21 phosphate ions in solution react with different surfaces of soil constituents [ clays; oxides of Fe and Al; org anic matter (OM); and Al and Fe compound coating surfaces of sand particles ] ( McBride 1994) Phosphorus is mainly adsorbed to metal oxides and clay mineral s as inner sphere complexes ( Goldberg and Sposito 1985) Since Fe or Al (hydr) oxide coatings were identified as major factor in a soils ability to absorb P, multiple chemical extrac tions that each account for different forms of Fe and Al are used as a way to asses a soils P sorption potential. Three chemical extractions that have been used in the past by many researchers to show the amount of Fe and Al in soils are the citrate di thio nite bicarbonate extraction (crystalline and amorphous Fe ; mainly amorphous Al ), the pyrophosphate extraction (organically bond Al and Fe), and the oxalate extract ion (amorphous and organically bond Fe and Al) (Freese et al., 1992; McKeague et al., 1971; Parfitt and Childs, 1988; Villapando and Graetz 2001) Some studies determined that Al plays a more dominant role th a n Fe in sorbing P ( Ballard and Fiskell 1974) For example, Vill a pando and Graetz (2001) showed a correlation of P sorption to numerous forms of Al (e.g., oxalate extractable Al, citrate di th ionite bicarbonate extractable Al, and p yrophosphate extractable Al) in Bh horizon samples using full P sorption isotherms with the highest correlation to P sorption for CuCl 2 extrac ta ble Al ; no positive relationship between P sorption maxima and Fe was r eported However, the lack of a positive relationship between Fe and P sorption found by Vill a pando and Graetz (2001) was most likely due to the fact that the soils used in the study contained a greater amount of Al than Fe. Other studies have shown that both Fe and Al play a dominant role in P sorption. For example, Yuan and Lavkulich (1994) and van der Zee and van Riemsdijk (1986) reported a strong correlation between P

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22 sorption and oxalate extractable Al and Fe in Spodosols Borggaard et al. (1990) showed that P sorption in a range of Danish soils was a function of both citrate di thionite bicarbonate and oxalate extractable Al and Fe This result was also supported by the findings of Nair et al. (1998) who attributed the high P sorption c apacity of Florida Bh horizons to the presence of oxalate extractable Al and Fe. Phosphorus Retention in Florida Soils Many of Florida sandy soils have low P sorption capacity ( Nair et al., 2004) due to low concentrations of metal oxides [ namely Al and Fe ( hydr ) oxide s] that are capable of forming surface bonds with orthophosphates ( Harris et al., 1996) Snyder et al. (2001) showed that the P leach ing potential of an acidic uncoated sand soil was much greater than a Fe or Al (hydr) oxide coated s subsurface horizons (e.g., Bh and Bt) have the capacity to sorb large amounts of P. In a study measuring the P retention characteristics of Spodosols and the potential for movement of P from surface (A) horizons to the underlying Bh horizon, Nair et al. (1998) reported that P sorption capacities of B h horizon soils was 1.5 to 2 times greater than overlying uncoated E horizon soils. Zhou et al (1997) concluded that metal OM complexes were the primary source of P sorption capacity in Bh horizon soils from Florida This finding was also supported by Villapando and Graetz (2001) who determined the ability of Bh horizons to adsorb P was due to low soil pH coupled with the accumulation of metals and organic C (V illapando and Graetz 2001) Therefore, Bh horizons can generally be considered to have high P retention capacities. Many studies have developed measurements to account for the P sorption capacities of soils and are able to predict if soil s wi ll act as P sinks or P sources.

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23 Measurements of Soil Phosphorus Retention Capacity The degree of P saturation (DPS), the P saturation ratio (PSR), and soil P storage capacity (SPSC) are measurements that account for the P retention capacity of a acidic soil by quantifying the relationship between soil P and P retaining soil minerals (mainly Al and Fe) (Chakraborty et al., 2011a; Maguire and Sims, 2002; Nair et al., 2004 ) The utility of the DPS and PSR relates to the fact that they tend to have discrete threshold values, within certain ranges of soils, above which the P in solution abruptly starts to increase in a linear fashion. The degree of P saturation (DPS) is calculated from a single extraction with acid ammoniu m oxalate ( DPS ox ) and relates ammonium oxalate P (P ox ) to the sum of oxalate extractable Fe (Fe o x ) and Al (Al o x ) by the following equation: DPS ox = [(P ox ) / (Al o x + Fe o x )] 100 where P ox Al o x and Fe o x are the concentration of oxalate extractable P, Al, and Fe expressed in mmol kg 1 and is an empirical factor that compares different soils with respect to P saturation ( Breeuwsa et al., 1995) An many studies (Schoumans, 2009; Sims et al ., 2002) but Nair and Graetz (2002) Bh horizons in Florida. Since oxalate extractions are not routinely conducted in soil testing labs, the concept of the P sa turation ratio was developed (PSR) (Maguire and Sims, 2002; Nair and Graetz, 2002) which relates the amount of M3 or M1 extractable P to the sum of M3 or M1 extractable Fe and Al. Maguire and Sims (2002) suggested the following equation to determine PSR based on the M3 extraction (PSR M3 ): PSR M3 = P M3 / (Al M3 + Fe M3 ),

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24 where P M3 Al M3 and Fe M3 are the concentrations of M3 extractable P, Al, and Fe expressed in mmol kg 1 In an effort to evaluate the relationship between widely reported DPS ox values of past studies to the more commonly used Mehlich soil extractant, Nair et al. (2004) developed the following equatio n to calculate DPS based on analysis of Mehlich 3 extracts ( DPS M3 ) was: DPS M3 = [(P M3 ) / (Al M3 + Fe M3 )] 100, w here P M3 Al M3 and Fe M3 are the concentrations of M3 extractable P, Al, and Fe expressed in mmol kg 1 and is an empirical factor that compares different soils with respect to P saturation. Nair et al. (2004) sh owed a strong correlation between DPS ox and DPS M3 demonstrating that both methods were equally appropriate for DPS calculations. S ince both PSR M3 and DPS M3 use results of tests that are readily available from most standard soil testing labs, these equatio ns provide a more practical way to assess the P saturation of a soil th a n using equations requiring oxalate extractable values. Maguire and Sims (2002) evaluated the potential of DPS ox and PSR M3 as environmental soil tests by comparing P in leachate from soil cores with different DPS ox and PSR M3 levels. The authors reported a change point of 56% and 0.23 for DPS ox and PSR M3 respectively, for five different Delaware soils. Phosphorus concentrations in leachate tended to increase rapidly when DPS ox or PSR M3 levels exceeded the change point. However, the authors did note that before these change points could be extrapolated to a wide range o f soil types, more research was needed to determine the effect of various chemical and physical properties of soil types on the change point values. The coefficient of determination for the relationship between leachate P and

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25 PSR M3 was much greater ( r 2 = 0 .78) then the relationship between leachate P and DPS ox ( r 2 = 0 .46). Thus, Maguire and Sims (2002) concluded that the PSR M3 showed excelle nt promise for identifying soils that represent an increased risk for P leaching losses. However, neither the DPS nor the PSR equations provide information on the amount of P that can added to the soil before the soil becomes a potential environmental con cern ( C hakraborty et al., 2011a) The SPSC equation is used to estimate the rem ain ing P sorption capacity of the soil. The SPSC is calculated based on oxalate, M1 or M3 extractable Al and Fe. Charakraborty et al. (2011a) reported the following equation for SPSC calculation based on Mehlich 3 extraction (SPSC M3 ): SPSC M3 = (Change point PSR M3 Soil PSR M3 ) (Fe M3 + Al M3 ) 31, w here Al M3 and Fe M3 are the concentrations of M3 extractable Al and Fe expressed in mmol kg 1 and change point PSR M3 is the thre shold value determined for a specific range of soil. When the SPSC value is positive the soil is a P sink, while a negative SPSC value indicates that the soil is a potential P source ( Chrysostome et al., 2007) The P status of a soil can affect the P leaching potential when applied as fill materials in urban settings. Phosphorus Leaching from Turfgrass Systems Phosphorus loss due to leaching has been considered a minor pathway in agricultural and urban systems because most soils and subsoils have relatively high P sorption capacities compared to the amount of P being applied ( Sims et al., 1998) However, Soldat and Petrovic (2008) reviewed several studies that highlighted situations under which P leaching could become a m ajor pathway for P loss in turfgrass systems, including: fertilized soils with low P sorption capacities, soils with high organic

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26 matter content, soils with large networks of macropores, and soils with elevated P levels caused by long term P fertilization regimes. Most research on P leaching from turfgrass systems was conducted on sand based zones for golf courses and athletic fields ( Soldat and Petrovic 2008) These sand based root zones have high infiltration rates and typically very low P sorption capacities ( Soldat and Petrovic 2008) and, therefore, may be comparable to some of Florida sandy soils. Results from numerous field studies showed that annual P leaching losses of ferti lized sands r anged from 0.03 to 6. 1 kg ha 1 with P concentrations in leachate observed at concentrations exceeding 13 mg L 1 (Soldat and Petrovic, 2008) However the golf courses and athletic fields in these studies received mainly soluble fertilizers inputs, were provided frequent irrigation, and included subsurface drainage systems, all of which may have prom oted P l eaching Most studies evaluating P leaching from fine textured soils found lower P leaching losses (ranging from 0.2 to 0.7 kg ha 1 ) th a n studies conducted on sandy soils ( Soldat and Petrovic 2008) However, Soldat and Petrovic (2008) noted that some studies conducted on fine textured soils still had relatively high P losses, ranging from 0.2 to 5.4 kg ha 1 Easton and Petrovic (2004) obse rved annual P leaching losses of 1.3 kg ha 1 for unfertilized turfgrass grown on a sandy loam soils. This was slightly lower than findings by Linde and Watschke (1997) who observed P leaching losses of 1.7 to 2.2 kg ha 1 However, many researchers did not report or consider soil P concentrations as a factor that could influence P leaching. Thus, research evaluating how P sources other than fertilizer (i.e., soil P and soil chemical properties) affect P leaching from tur fgrass areas is needed. Soil properties can greatly influence nutrient fate and bioavailability and should be considered for all turfgrass management strategies.

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27 Phosphorus Fertilizer and Soil Effects on Turfgrass Quality Most research investigating the ef fect of soil physical properties on turfgrass establishment has focused on golf course management. McCoy (1998) investigated the effects of organic and sand amendments on the soil physical properties that were related to turf establishment for golf course putting greens. The results showed that increasing the OM content of the soil led to an increase in the soil water holding capacity, a decrease in soil bulk density, and improved soil cation exchange capacity ( McCoy 1998) Ntoulas et al. (2004) concluded that higher quality turf was observed in sandy soils treated with compost amendments. Improved turf quality, was mainly attributed to an increase in soil water and nutrient holding capacity. Results of the studies conducted by McCoy (1998) and Ntoulas et al. (2004 ) suggested that soils with higher levels of OM were effective at producing quality turf th a n soils with low OM levels. Brar and Palazzo (1995) investigated the effects of different soil textures on turfgrass root development. The authors concluded that roots grew significantly deeper in sandy textured soils th a n in sandy loam textured soils because of the coarser grain size and wider pore spaces in sandy soil, which presented less resistance to root elongation. However greater root mass was observed in the sandy loam soil, which was attributed to the smaller pores that can better retain water and nutrients th a n la rger pores that dominate the sandy soils. Research relating turfgrass quality to soil nutrient content has mainly focused on fertilizer studies that determined the relationship between turfgrass quality and various fertilizer application rates ( Christians et al., 1979; Colclough and Canaway, 1989; Fry et al., 1989; Liu et al., 2008; Lodge et al., 1990 ) Phosphorus fertilizer additions have been shown to help stimulate turfgrass root formation and early season growt h in the young

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28 tissues near turfgrass root tips ( Landschoot 2003) An early symptom of P deficiency in turfgrass is the appearance of a dark green coloration in older leave blades. As the deficiency worsens, the turfgrass develops a purplish to reddish coloration that can eventually lead to leaf tip necrosis and poor see d development ( Heydari and Balestra, 2008) Another visual sign of P deficiency in turfgrass is wilting, which may be confused with water stress ( Heydari and Bal estra 2008) Christians et al. (1979) found no significant clipping, root development, or quality response of Agrostis palustris (creeping bentgrass ) to applied P in a sand media. However, Fry et al. (1989) reported a significant turf quality response to adding P fertilizer, but only for the first fertilizer rate increment from 0 to 5 kg ha 1 P per month; no further quality response was rep orted with higher fertilizer rates Some researchers considered the effects of initial soil nutrient levels on turfgrass quality responses to different fertilizer regimes. For example Liu et al. (2008) determined the P requirements of STA grown in sandy soils by inducing P deficiency in the turf and then applying different P fertilizer rates to determine the critical minimum P tissue level and c ritical minimum soil P concentration. The authors noted when STA was grown i P concentrations (<10 mg kg 1 ) and received no P fertilizer applications that P deficiency in STA was not induced until almost one year after planting. Once P deficiency was induced, STA recovered f rom P deficiency status after 4 weeks of P fertilizer applications; the higher the P application rates the faster the recovery time. Turf quality ratings remained above acceptable levels (6.0 out of 9 .0) for all fertilizer rate treatments, including the control (no P added), for the first 10 to 12 week s of the study after P deficiency was induced, which suggested that quality STA

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29 could be sustained for months on soils with very low soil P concentration s ( Liu et al., 2008) Liu et al. (2006) r eported a critical tissue P concentration of 1.6 g kg 1 (on a dry weight basis) for STA grown in a hyd roponic study. In a follow up study, Liu et al. (2008) reported a slightly higher critical tissue P concentration of 1.9 g kg 1 (on a dry weight basis) for STA grown on sandy soils. Liu et al. (2008) recommended no P fertilization if soil M1 P concentration was above 10 mg kg 1 or tissue P level exceeded 1.8 g kg 1 (on a dry weight basis). Liu et al. (2009) reported that optimal growth of STA can be obtained at very low soil test P levels and saw little growth response differences to increased P fertilization rates once critical tissue P levels were obtained. Current Situation and Research Objectives Soils in urban settings can display a wide variety of chemical and phy sical properties due to the mixing of soil layers during construction activities (Scharenbroch et al., 2005) Urban soils tend to have higher bulk densities, lower OM contents, lower microbial activities, and usually higher P concentrations then typical topsoils ( Scharenb roch et al., 2005) Urban soils often build up very high levels of soil test P as a result of years of fertilizat ion ( Scharenbroch et al., 2005) As a result of repeated P applications and natural soil conditions, a standard soil P test (M3 or M1) may reveal P concentrations that would not allow a Florid a homeowner to apply more than 1.07 g m 2 P based on provisions in the urban turf rule ( Trenholm 2010) Bans on P fertilizer applications may further prevent the establishment of healthy turfgrass and reduce assimilation of other essential nutrients, mainly N, by turfgrass. Un healthy turf grass does not effectively use water and fertilizer due to inadequate root system development ( Beard a nd Green 1994) Since turfgrass is the dominant component of the pervious areas in urban landscapes (M ilesi et al., 2005) and often times is highly managed with

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30 fertilizer and water inputs, it is important to understand the fate and cycling of nutrients in turfgrass systems. By understanding the pos sible fate of added P, homeowners may be able to apply appropriate amounts of P for turfgrass usage and help limit P losses (i.e., leaching and runoff) to the surrounding environments. Since Bh horizons have unique properties that can bind P, large areas w ith Bh derived fill used as topsoil may limit healthy turfgrass establishment. Some studies have shown that bahiagrass and some deep rooted trees were able to remove and effectively uptake some P that is bound up in Bh horizons (Chakraborty et al., 2011b; Ibrikci et al., 1999; Obour et al., 2011 ) However, past research has not focused on the effects of using Bh horizons as a topsoil fill. Therefore, additional research is needed to determine if applying Bh horizons as a topsoil fills will affect the establishment and nutrient content of STA and affect the leaching of P from urban systems. The objectives of this study were to 1) d etermine the response and quality of STA grown on Bh horizon fill material s, and 2) to quantify leaching of P from Bh and non Bh fill soils.

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31 CHAPTER 2 E FFECT OF SPODIC FILL MATERIALS ON THE GROWTH AND ESTABLISHMENT OF ST. AUGUSTINEGRASS Introduction Stenotaphrum se cu ndatum Walt. Kuntze ( s t. a ugustinegrass) is the most popular turfgrass choice in Florida, covering roughly 800,000 h a of lawn s in urban areas throughout the state ( Liu et al., 2008; Trenholm et al. 2011) St. a ugustinegrass (STA) has moderate shade tolerance, low drought tolerance and is best establish ed in soils with a pH range of 4.8 to 7.5 (Sartain, 2012; Trenholm et al., 2006; U.S. Department of Agriculture 2010) St. a ugustinegrass is a coarse textured stoloniferous grass that roots at the nodes. Since STA and other turfgrasses represent the largest portion of pervious areas in urban landscapes ( Milesi et al., 2005) and are often highly managed by applying fertilizer and water, it is imp ortant to understand the bioavailability and fate of nutrients added to the soil. Soil quality in urban areas often presents challenges when establishing turfgrass ( McCoy 1998) Native topsoil is usually altered or removed completely by heavy construction equipment during land preparation for residential development ( Lehmann and Stahr 2007) Soil fill material is often brought in during constr uction activities to generate a level foundation that can support a structure. These fill materials have varying physical and chemical properties that a ffect nutrient bioavailability and may prevent the establishment of a fully functioning, healthy turfgra ss system ( Pouyat et al., 2007; Scharenbroch et al., 2005; Short et al., 1986 ) Unhealthy turfgrass with an inadequate root system does not effectively use water and fertilizer and could ultimately result in large quantities of nutrients be lost to the surroun ding environment ( Beard and Green 1994)

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32 Many studies have linked the degradation of surface water quality (e.g. harmful algal blooms, eutrophication, and dead zones) to the discharge of nutrients mainly nitr ogen (N) and phosphorus (P)] from point and non point sources (Anderson et al., 2002; Riegman, 1995; Sharpley et al., 2003; Smith, 1983 ) In an effort to reduce the occurrence of algal bloom outbreaks and to help slow down the eutrophication of surface waters, Florida adopted an urban turf fertilizer rule in 2008. The urban turf fertilizer rule limits P fertilizer applic ations to turfgrass in urban areas ( Trenholm 2010) For example, the urban turf fertilizer rule restricts single applications of P to 0.54 g m 2 per application and annual applications of P to 1.07 g m 2 ( Trenholm 2010) Phosphorus fertilizer applications exceeding the annual application limit are only permitted if a soil test indicates the need for P. However, standard soil tests [ i.e., Mehlich 1 (M1) an d Mehlich 3 (M3)] do not account for a soils capacity to retain P and may overestimate the pool of available P for plant uptake The degree of P saturation (DPS) and the P saturation ratio (PSR) are measurements that account for the P retention capacity o f a soil by quantifying the relationship between soil P and P retaining soil mineral s [ mai nly aluminum (Al) and iron (Fe)] ( Maguire and Sims, 2002; Nair et al., 2004) Soil tests that deter mine P saturation can more accurately assess soil P status and provide insight about the need for additional fertilizer to achieve adequate plant growt h. Phosphorus is a critical macronutrient for turfgrasses and has been shown to help stimulate root forma tion and early season growth in the young tissue near root tips ( Landschoot 2003) However, Liu et al. (2008) suggested that no P fertilization would be recommended for STA when soil M 1 P concentration exceeded 10 mg kg 1 or tissue

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33 P level exceeded 1.8 g kg 1 on a dry weight basis. Besides soil P status, other soil properties can greatly affect the quality and establishment of turfgrass (McCoy, 1998; Rowland et al., 2009; Sartain, 2012; Soldat et al., 2007 ) Brar and Palazzo (1995) showed that mass of Festuca arundmacea Schreb. (tall fescues ) and Festuca ovina Koch. (hard fescues ) were significantly affec ted by soil texture. Brar and Palazzo (1995) observed greater root mass when tall and hard fescues was grown in the sandy loam soil because the smaller pores retained water and nutrients longer than the large pores in the sandy soils. Rowland et al. (2009) concluded that the high fertilizer and water inputs required to establish Cynodon dactylon ( bermudagrass ) on coarse textured soils was due to the soils low organic matter (OM) content. Carrow (1989) reported that there are many soil physical, chemical, and biological properties that limit root growth in turfgrass, including soil layers, soil tex ture, soil temperature, water deficiency, acidic soils with high Al content, soil nutrient deficiencies or excesses, soils with high salt le vels, and root feeding insects. Carrow (1989) also determined that growth of new roots was dependent on carbohydrat e production from turf shoots above ground, so any factors that limit shoot density or carbohydrate production will also affect root growth. Sartain (2012) reported that soil pH is a very important factor in influencing turfgrass quality because soil pH influences nutrient availability and toxicity. Since Spodosols represent a dominant soil order in Florida ( Stone et al., 1993) and exhibit morphological characteristics (mainly the dark brown color) that are similar to native topsoil, spodic (Bh) derived soils are sometimes used as topsoil fill material during residential construction T he frequency and land coverage of Bh fill materials in

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34 urban areas is currently unknown The low pH values and high concentrations of organically complexed metals (Al and Fe) common to most Bh horizons (Villapando and Graetz 2001) may severely limit P availability to turfgr ass grown on Bh soils. Phosphorus exists in many different chemical forms and species (i.e., H 3 PO 4 H 2 PO 4 HPO 4 2 and PO 4 3 ) in the soil solution environment ( Brady and Weil, 2002) The presence of these P species can be directly related to soil pH, which in turn, has a direct effect on the amount of plant available P. In acid soils (pH < 5.5), P ions r eact with Fe and Al oxides to form surface complexes or react with dissolved Fe 3+ and Al 3+ ions to form insoluble hydroxyl phosphate precipitates ( Brady and Weil 2002) Phosphorus limitations may be further accelerated due to the fertilizer laws that strictly govern the amount of P fertilizer allow to be applied to turfgrass in urban settings. However, p ast research showed that Paspalum notatum (bahiagrass ) and some deep rooted trees were able to remove and effectively take up a portion of soil P complexed within Bh horizons (Chakraborty et al., 2011b; Ibrikci et al., 1994; Ibrikci et al., 1999; Obour et al., 2011 ) The relatively higher OM content and elevated clay content found in Bh horizons when compared to other sandy soils (Obreza and C ollins 2008) may result in more water and nutrient retention for turfgrass establishment. However the high Al cont ent found in Bh horizons may limit root growth and effect turfgrass establishment (Carrow, 1989) The effects of using Bh horizon materials as soil fill on the establishment and quality of STA has not been evaluated. Therefore, the objective of this study was to d etermine the growth response and quality of STA planted on Bh and non Bh derived fill material s.

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35 Materials and Methods S ite Locations and Soil Sampling Five subsoils were obtained from two different geographical locations in Florida. Two soil samples were collected from an active borrow pit located 20 km southeast of Jacksonville, FL. Soils were removed from the ground by backhoe operations prior to our sampling One soil was collected from the Bw horizon of a Paola sand (Hyperthermic, u ncoated Spodic Quartzipsamments) ( Soil Survey Staff 2010) T he second soil was collected from a Bh horizon of a Pomello fine sand (Sandy, siliceous, hyperther mic Oxyaquic Alorthod ) ( Soil Survey Staff 2010) Soil was also collected from a new residential housing development located east of Fruit Cove, FL. Various soil horizons were exposed in a circular trench that was excavated prior to sampling. The expo sed Bh and E horizon s of a St. Johns sand (Sandy, siliceous, hyperthermic Typic A laquods) ( Soil Survey Staff 2010) w ere collected. A n additional soil sample was collected near Labelle, FL at a private cattle farm dominated by pine flatwoods vegetation A small circular soil pit was hand dug using a shovel. Soil was excavated from the Bh1 horizon of a Myakka sand (Sandy, siliceou s, hyperthermic Aeric Alaquods) ( Soil Survey Staff 2010) Experimental Design Forty soil columns were constructed by cu tting polyvinyl chloride (PVC) pipe ( 15.2 cm internal diameter) into 30.5 cm long sections. Forty 15.2 cm diameter endcaps were filled with three pieces of cheesecloth that had been cut into 15.2 cm circular pieces and c au lked to the bottom of each endca p. A mixture of deionized water washed sand (186 g) and pea gravel (614 g) was added to each endcap to allow for free drainage of water and to help prevent soil loss from the column. Endcaps were then attached to the

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36 bottom of each PVC column and water res istant caulk was applied to the outside and inside lips of the endcap to prevent water leakage. A 1.3 cm hole was drilled into the center of each endcap to allow for water drainage. The experiments were conducted inside a sawtooth production house at the U niversity of Florida I nstitute of Food and Agricultural Sciences (UF IFAS) Gulf Coast Research and Education Center in Wimauma, FL. Each air dried soil was packed into eight PVC columns; four columns were used for a 9 week turfgrass establishment study (1 1 May to 11 July 2011) and four columns for a 27 week turfgrass establishment study (11 May to 10 Nov 2011). Soils were packed into the columns in 1000 g increments by alternating packing with ten taps of a hand made tool (steel rod welded to a 10.2 cm di ameter steel circle). The packing tool was moved in a circular pattern in between each tap to ensure the entire column was evenly packed. Packing was performed until the soil level was within a 1.3 cm of the top of the column to allow room for placement of (Council Growers, Inc., Ruskin, FL) were cut from sod pallets using a 15.2 cm cup cutter. Soil was gently washed off of the turfgrass roots using a low pressurized hose prior to the installation of sod in the colum ns. Sod was installed by placing the 15.2 cm turf cutouts onto the packed soil columns. Excess turfgrass extending over the edge of the 15.2 cm radius of PVC column was trimmed evenly with the side walls of the column using pruning shears. Irrigation and Fertilizer Application Columns were irrigated with potable well water that contained no measurable molybdate reactive P ( < 0.09 mg L 1 ) ( Pierzynski et al., 2009) using a drip irrigation system that was regulated to 206 8 k Pa and connected to a sand filtration system. Each

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37 turf column was outfitted with two drip emitter stakes (Arrow Dripper; MMXI NetaFim Irrigation, Inc., Fresno, CA) that were placed in the middle of the column; each emitter applied 0.95 L hr 1 of water. Irrigation events were scheduled using an automated timer to ensure that the turf received ad equate water for optimal growth. The amount of water applied to each column was determined by following UF IFAS irrigation recommendations for STA in southern Florida (Trenholm et al., 2011; Trenholm et al., 2006) The irrigation sched ule for the first 40 days after planting (DAP) is presented in Table 2 1 At 21 DAP, the two drip emitter stakes were removed from each column and replaced with a single, adjustable spray emitter (Shrubbler 360; Antelco Corp., Longwood, FL) due to concer ns of uneven wetting of the soil columns. The spray emitters were adjusted individually until an application rate of 20.8 2.84 L hr 1 of water was achieved for all emitters. From 40 DAP until 82 DAP, the turf received 0.97 cm of water twice a week (Monda y and Thursday of each week at 0800 HR for a 30 sec run time). From 85 DAP until the end of the experiment, the t urfgrass received 1.02 cm of water twice a week (Monday and Thursday of each week at 0800 HR for a 32 sec run time ) The amount of water was increased from 0.97 to 1.02 cm of water because turfgrass showed signs of water stress due to increasing air temperatures in summer. Soil columns were fertilized with a water soluble 36N 0P 5K fertilizer mix (Miracle Gro Water Sol uble Lawn Food; The Scotts Company, LLC, Marysville, OH) that was specifically formulated for lawns. Columns were fertilized at a n itrogen (N) rate of 2.4 g m 2 following UF IFAS recommendations for STA (Trenholm et al., 2011). During the first fertilizer application (applied 30 DAP), 0.059 g m 2 P was applied as a starter application by dissolving 0.168 g NaH 2 PO 4 into the water soluble fertilizer solution.

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38 During subsequent fertilizer applications (approximately every 30 d), no P fertilizer was applied. Fertilizer was applied to the columns by hand using pre measured aliquots (half the volume of irrigation applied) the fertilizer solution. After the fertilizer was applied, the columns were irrigated with the re m a in ing volume of water to help move the fert ilizer into the soil and prevent foliar burn on the turfgrass blades. Pesticide Applications On 20 July 2011 (71 DAP), Attain Greenhouse (Prescription Treatment brand insecticide, St. Louis, MO) was sprayed onto the turfgrass columns at a low rate (0.2 6 mL L 1 water) to help combat the outbreak of chinch bugs. Attain was re applied at a higher rate ( 1 9 mL L 1 water) on 25 July 2011 (75 DAP) to ensure that any newly hatched chinch bugs were also treated. Attain Greenhouse and Marathon ( Olympic hortic ultural products Mainland, PA) pesticides were both applied to turfgrass columns on 4 Aug 2011 (85 DAP) to ensure that any remaining chinch bugs were killed. Marathon is a granular slow release pesticide and was applied by scooping half of teaspoon of pesticide into each column, afterwards the Attain pesticide was applied to the columns by drenching the columns with predetermined aliquots at an application rate of 6.4 1 water. On 26 Aug (106 DAP), Avid (KORUSA pest control, INC., Duluth, G A ) pesti cide was sprayed at a rate of 0. 32mL L 1 water to help combat an outbreak of spider mites in turfgrass columns. The pesticide (Avid ; KORUSA pest control, Inc ., Duluth, G A ) was reapplied at the same rate on 1 Sep t. 2011 (113 DAP) to treat any newly hatch s pider mites. On 25 Oct 2011 (167 DAP), 500 mL of a new pesticide (Judo Olympic horticultural products Mainland, PA) was sprayed onto the turfgrass columns at a application rate of 264 mL L 1 water to kill any remaining spider mites that were resistant to the Avid pesticide treatments

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39 Characterization of Soil Properties The different s oil horizon samples that were collected were air dried at 25 2C for 10 d and sieved to pass a 2 mm screen. Initial soil bulk density of soil treatments in PVC column s were calculated by dividing the oven dried mass of soil packed into columns by the PVC columns area Soil texture was determined using the hydrometer method ( Bouyoucos 1962) Soil pH (1:2 soil to deionized water ratio) and OM (loss on ignition) were determined by standard methods of the UF IFAS Analytical Research Laboratory (ARL) in Gainesville, FL ( Mylavarapu 2009) Soil samples were extracted using the Mehlich 3 (M3) method (1:7 ratio of soil to 0.2 M CH 3 COOH + 0.25 M NH 4 NO 3 + 0.015 M NH 4 F + 0.013 M HNO 3 + 0.001 M EDTA) ( Baker et al., 2002) Mehlich 3 extracts were analyzed for P, Calcium (Ca), Al, Fe, and Potassium (K ) using inductively couple d plasma atomic emission spectroscopy (ICP AES ) at the ARL Water soluble phosphorus (WSP) was extracted by following method of Self Davis et al. (2009) Soluble P in filtrate was determined on a spectrophotometer (Genesys 20; Thermo Fisher Scientific, Madison, WI) at 882 nm following the Murphy and Riley (1962) procedure. The M3 PSR (PSR M3 ) values for the soils were calculated using the following equation: PSR M3 = P M3 / (Al M3 + Fe M3 ) where P M3 Al M3 and Fe M3 are the concentration of M3 P, Al, and Fe expressed in mmol kg 1 ( Maguire and Sims 2002) Degree of P saturation was calculated using the following equation: DPS M3 = [(P M3 ) / (Al M3 + Fe M3 )] 100, w here P M3 Al M3 and Fe M3 the concentration of M3 P, Al, and Fe are expressed in mmol kg 1 and is an empirical factor that compares different soils with respect to P

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40 saturation ( Nair and Graetz 2002) Soil electrical conductivity (EC) and volumetric water content were obtained weekly using the Stevens POGO portable soil sensor (Stevens Water Monitoring Systems, Inc., Portland, OR) with an EC detecti on limit 0.01 S m 1 At the end of 9 and 27 weeks after planting (WAP) the soil from each column was removed and air dried at 25 2C for 10 d and sieved to pass a 2 mm screen. All soil samples collected at 9 and 27 WAP were analyzed for the same parame ters as outline for pre experiment parameters expect for M3 nutrients. Soil samples collected at harvest were extracted using a different M3 method (1:10 ratio of soil to 0.2 M CH 3 COOH + 0.25 M NH 4 NO 3 + 0.015 M NH 4 F + 0.013 M HNO 3 + 0.001 M EDTA) (Mehlich, 1984; Sims 2009b) Turf grass Quality and Chlorophyll Content (SPAD) Turfgrass quality in each column was determined weekly using the National Turfgrass Evaluation Program (NTEP) numerical rating system The NTEP rating system uses a scale from 1 to 9, where 1 indicates dead, brown t urfgrass; 6 indicates minimally acceptable turfgrass; and 9 indicates the highest quality turfgrass (Shearman and Morris 2011) Turfgrass blade chlorophyll content was estimated weekly, starting at 5 WAP, using a hand held Special Products Analysis Division (SPAD) meter (SPAD 502; Konica Minolta Sensing Americas, Inc., Ramsey, NJ). Tissue SPAD readings were reported as the average of three different turf grass blades collected from each soil column Turf grass Biomass Turfgrass height was maintained at 9 cm above the soil surface. Clippings were removed using shears when turfgrass height exceeded 9 cm ( approximately every 20 to 40 days ) Turfgrass was harvested from 20 columns at 9 WAP and from the remaining

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41 20 columns at 27 WAP, by sliding a knife bl ade around the edges of the PVC columns and inverting the column to allow the turfgrass and soil to slide out onto a tray. Soil was removed from the roots by gently shaking the turfgrass cutouts ; soil was saved for further analysis. The harvested turfgrass was then separated into above ground (pelt, thatch, and stolons) and below ground (roots) portions Roots were removed from the above ground portion of the turfgrass using scissors Shoot counts were determined for each pelt by counting and recording the number of shoots on each pelt. Turfgrass roots were placed in a 2 mm sieve and any soil remaining on them was washed off under gently flowing water. The wet roots were then wrapped in a paper towel. Tissue Nutrient Content After collection, clippings, sh oots, pelts, and roots were dried at 41 2C, weighed, and ground using a Wiley mill (Arthur H. Tomas Co., Swedesboro, NJ). Turfgrass clippings were combined to generate a single composite sample for each soil type from 0 to 9 WAP and 10 to 27 WAP. One gr am subsamples of plant tissues (root, pelt, and clippings) were then weighed into ceramic crucibles and ashed in a muffle furnace for 6 h at 500C. Phosphorus and K were determined by dissolving the ash in 6 M HCl ( Mylavarapu 2009) and analyzed by ICP AES at the ARL in Gainesville, FL. Tissue N was determined by following standard methods for total Kjeldahl N (TKN) plant tissue digestion ( Mylavarapu 2009) and analyzed on a flow segmented analyzer (Astoria 2 Analyzer; Astoria Pacific International, Clackamus, OR) at the ARL in Gainesvi lle, FL. Total nutrient content of STA pelts, roots, and clippings were calculated by mul tiplying nutrient concentration by dry biomass weight

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42 Data Analysis The experiment was designed as a completely randomized design with soil as the only factor with five treatments. Each soil treatment was randomly assigned to the c olumns, with four replicatio ns for each treatment for the 9 week establishment period, and four replications for the 27 week establishment period. Soil samples with concentrations of P M3 and Fe M3 below the detection limit were assigned a value of half the detection limit. Soil treatment effects on soil properties, turfgrass biomass, and turfgrass tissue nutrients were analyzed using the PROC MIXED procedure in SAS 9.3 with soil treatment as a fixed effect and replication as a random effect ( SAS Institute 2012) Normality was checked by examining histogram and normality plots of the conditional residuals. Soil P M3 and Fe M3 PSR M3 DPS M3 soil OM, and root mass were lo g transformed prior to statistical analysis for 9 week harvest data. Soil P M3 and Al M3 PSR M3 DPS M3 soil OM, root mass, root K, and root TKN; pelt P, pelt K, and pelt TKN; were log transformed prior to statistical analysis for 27 week harvest data. Weekly turfgrass visual ratings were analyzed by week for columns harvested at 27 WAP due to an overall significant soil treatment week interaction. Weekly SPAD readings were analyzed by week for columns harvested at 9 WAP due to an overall significant s oil treatment week interaction. All remaining parameters were analyzed using a repeated measures model with a heterogeneous variance in the covariance structure of R. Relationships between soil and turfgrass parameters were determined using a Pearson cor relation analyzed by the PROC CORR procedure in SAS 9.3 ( SAS Institute 2012) with a significant level of = 0.05. Statistical analysis was not able to be performed on

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43 turf clipping nutrient content (P, K, and TKN) due to a lack of replications of composite samples. Results Soil Characterization The initial bulk densit y of the Pa ola Bw and St. Johns E soils were significantly higher than the other three soil s. T he bulk density of the Myakka Bh1 and St. Johns B soil were significantly lower than the other three soil s (Table 2 2). All five soils had a soil texture of sand (data not shown). The pH of the initial soil samples ranged from 4.1 to 5.8 (Table 2 3). The three Bh horizon soils (Pomello, St. Johns, and Myakka) had pH values less than 4.3 while the St. Johns E and Paola Bw soils had pH values greater than 5.0 (Table 2 3). The three Bh soils (Myakka, Pomello, St. Johns) had significantly lower pH values than the St. Johns E and Paola Bw soils at the 9 and 27 week harvest; in addition the Myakka Bh1 soil had significantly lower pH values than the other two Bh soils ( Pomello and St. Johns) at the 9 week harvest (Table 2 3). The OM concentrations of the initial soils ranged from 1.6 to 67.5 gkg 1 (Table 2 3). The soil OM content of the Myakka Bh1 and Pomello Bh soils were not statistically different, but soil OM was significantly higher than the St. Johns Bh, Paola Bw, and St. Johns E soil at the 9 week harvest date (Table 2 3). Similar trends in OM concentrations were determined for soils collected at the 27 week harvest date (Table 2 3). The initial M3 Ca (Ca M3 ) concentrations of the soil were all below 29.3 mgkg 1 expect for the Myakka Bh1 soil which had a Ca M3 concentration of 333 mgkg 1 (Table 2 3). The Myakka Bh1 soil had significantly higher Ca M3 concentration then the other four soil s at the 9 and 27 week harvest date (Ta ble 2 3). The Paola Bw soil had the highest initial Fe M3 concentration of all soil s, while the Pomello Bh and St. Johns E soils had initial Fe M3

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44 concentrations below the detection limit (<5.0 mg kg 1 ) ( Table 2 3). The Paola Bw had significantly higher Fe M3 concentrations than the other four soil s at the 9 and 27 week harvest dates (Table 2 3). Initial soil P M3 concentrations ranged from <12.5 to 193 mgkg 1 with t he Pomello Bh and Paola Bw soil s containing the highest P M3 concentrations of the soil s while the Myakka Bh1, St. Johns E, and St. Johns Bh soils had P M3 concentrations below the detection limit ( 12.5 mg kg 1 ) (Table 2 3). Similar trends were determined in P M3 concentrations of soils collected at the 9 and 27 week harvest (Table 2 3). Soil test interpretations are not available for P M3 concentrations, but they are available for M 1 P (P M1 ). Mylavarapu et al. (2002) provided the following equation to covert P M1 to P M3 values for comparison: P M3 = 1.43 (P M1 ) +18.6 Based on P M1 soil test interpreta tions provided by Kidder et al. (2003) and Sartain (2012) and using the M1 to M3 conversion equation provided by Mylavarapu et al. (2002) both the Pomello Bh and Paola (P M3 > 105 mgkg 1 ) while the remaining three soils (Myakk Bh 1, St. Johns Bh, and St. Johns M3 < 33 mgkg 1 ) All soils had M3 K (K M3 ) concentrations (data not shown) below the detection limit ( 12.5 mg kg 1 ) M3 < 33 mgkg 1 ) ( Kidder et al., 2003) The three Bh soils (Myakka, Pomello, and St. John s) had the significantly higher Al M3 concentrations than the Paola Bw and St. Johns E soils (Table 2 3), with the Pomello Bh soil having the highest Al M3 concentrations at the 9 and 27 week harvest (Table 2 3).

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45 Initially the Pomello Bh soil had the highest WSP concentrations of all the soils, while both St. John soils had no detectable WSP (Table 2 3). The Pomello Bh soil had significantly higher WSP concentrations then the other f our soils at both the 9 and 27 week harvest dates (Table 2 3). Initially, both the Pomello Bh and Paola Bw soil s had PSR values over 0.1, while the remaining soil s had PSR values all below 0.031 (Table 2 3). The Paola Bw soil had significantly higher PSR M3 values then the other four soi ls at 9 and 27 week harvest (Table 2 3). Similar trends between PSR and DPS values were calculated for soils at the beginning and 9 and 27 week harvest dates (Table 2 3). When all soils where analyzed together there was no statistically difference in PSR DPS, WSP, and P M3 values from the 9 to 27 week study. However, when soil parameters were analyzed by soil treatment some significant differences were determined. The Paola Bw soil had significant decrease between soil WSP and P M3 concentrations from 9 t o 27 WAP which was accompanied by a significant increase in PSR M3 and DPS M3 values from 9 to 27 WAP. The St. Johns Bh had significant increase in PSR M3 DPS M3, and P M3 from 9 to 27 WAP. The Myakka Bh1 soil had a significant decrease in WSP concentrations from 9 to 27 WAP. All other soils had no statistical differences in PSR M3 DPS M3 and P M3 values from 9 to 27 WAP. Splitting the soils into non Bh and Bh soil types greatly increased their r values for correlation s between soil WSP concentrations and other soil parameters at 9 and 27 WAP. Soil WSP was highly correlated to P M3 ( r = 0.95, P = 0.0003), PSR M3 ( r = 0.98, P < 0.0001), and DPS M3 ( r = 0.98, P < 0.0001 ) for the two non Bh soils (Paola Bw and St. Johns E) harvested at 9 WAP. For the three Bh so ils harvested at 9 WAP, soil WSP was highly correlated to P M3 ( r = 0.94, P < 0.00 0 1), PSR M3 ( r = 0.94, P < 0.0001), and

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46 DPS M3 ( r =0.94, P < 0.0001 ) Soil WSP concentrations of non Bh soils harvested at 27 WAP were highly correlated to the following soil para meters: P M3 ( r = 0.89, P = 0.003), PSR M3 ( r = 0.88, P = 0.004), and DPS M3 ( r = 0.88, P = 0.004) Soil WSP concentrations of Bh soils harvested at 27 WAP were highly correlated to P M3 ( r = 0.98, P < 0.0001 ), PSR M3 ( r = 0.98, P < 0.0001), and DPS M3 ( r = 0.98, P < 0.0001). The mean of weekly soil EC values for the entire 9 and 27 week harvest periods were below the detection limit (<0.01 S/m) (data not shown). Therefore, salt build up related to fertilizer and irrigation applications to the turf was no t evident. There was not a significant soil treatment sampling date interaction determined for soil volumetric water content for the 9 or 27 week establishment periods. However, soil treatment (Figure 2 1 ) and measurement date (data not shown) effects w ere determined for soil volumetric water content ( P ). The soil volumetric water content of the St. Johns Bh soil was not statistically different than the Myakka Bh1 and Pomello Bh soil but was significantly higher than the Paola Bw and St. Johns E soils during the 9 week establishment period (Figure 2 1 ). No statistical difference was determined between the soil volumetric content of the St. Johns Bh and Myakka Bh1 soils ; however the St. Johns Bh soil had significantly higher soil volumetric conten t than Pomello Bh, Paola Bw, and St. Johns E soils during the 27 week establishment period (Figure 2 1 ). In general, the soil volumetric water content of all soil treatments slightly decreased throughout the 27 week study except for the Myakka Bh1 soil whi ch had a slight increase in soil volumetric water content (Figure 2 1 ). Turf grass Quality Ratings and Chlorophyll Content (SPAD) No significant soil treatment sampling date interaction was determined for visual ratings during the 9 week establishment study; therefore, the weekly data was analyzed

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47 over the whole sampling date. No significant soil treatment effect was determined for mean visual quality ratings fo r STA rated during the initial 9 week establishment period ( P > 0.05 Figure 2 2 ). There was a significant soil treatment sampling date interaction noted for visual ratings during the 27 week establishment study; therefore, the data was analyzed separate ly for each weekly sampling date ( ). We reported a significant soil treatment effect on turfgrass quality graded at 11, 12, 15, 17, 25, and 27 WAP (Figure 2 3 ). In general, visual quality ratings of STA grown on the Myakka Bh1 were not statisticall y different than STA grown on Pomello Bh, St. Johns Bh and Paola Bw soils but were significantly higher than quality ratings of STA grown on the St. Johns E soil. However, mean weekly quality ratings of STA grown on all soil treatments declined to below th e minimally acceptable rat ing of 6.0 by the end of the 27 week study period (Figure 2 3 ). A significant soil treatment sampling date interaction was determined for turfgrass SPAD readings measured during the 9 week establishment study; therefore, the da ta was analyzed separately for each weekly sampling date. There was a significant soil treatment effect on turfgrass SPAD readings at 5, 8, and 9 WAP ( P 0.05 Figure 2 4 ). Although there was a soil treatment sampling date interaction determined for SPA D readings, no clear trend of a single soil having significantly higher SPAD readings than other soils was determined, as it varied from week to week (Figure 2 4 ). No significant soil treatment sampling date interaction was determined for STA SPAD readings collected during the 27 week establishment period, therefore the mean of all weekly SPAD readings throughout the whole 27 week study were reported (Figure

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48 2 5 ). However, significant soil treat ment (Figure 2 5 ) and significant sampling date effects (data not shown) were determined for turfgrass mean weekly SPAD readings collected during the 27 week establishment period ( P ). The SPAD reading of STA grown on the St. Johns E soil were not st atistically different than SPAD readings of STA grown on St. Johns Bh soil but were significantly higher than SPAD readings of STA grown on the Myakka Bh1, Pomello Bh, and Paola Bw soils during the whole 27 week establishment period ( P 0.05 Figure 2 5 ) Turf grass Biomass No significant soil treatment sampling date interaction was determined for STA clipping biomass during the 9 and 27 week study periods. No significant soil treatment effect was determined for STA clipping biomass collected during th e 9 week study ( P > 0.05 Table 2 4). However, there was a significant soil treatment effect determined for STA clipping biomass collected during the 27 week establishment period ( P Table 2 4). St. Augustinegrass grown on the Myakka Bh1, Pomello Bh and St. Johns Bh soils produced clipping biomasses that were not statistically different but were all significantly greater than clipping biomass of STA grown on the St. Johns E soil during the 27 week establishment period (Table 2 4). No significant so il treatment effect was determined for pelt dry biomass at the 9 and 27 week harvest ( P > 0.05 Table 2 4). A significant soil treatment effect was determined for root dry biomass at the 9 and 27 week harvest ( P Table 2 4). No statistical differe nces were determined for root biomass of STA grown on St. Johns Bh, Paola Bw, and St. Johns E soil however, STA grown on the St. Johns Bh soil did produced significantly higher root biomass than STA grown on the Myakka Bh1 and Pomello Bh soils during the 9 week establishment period (Table 2 4). St.

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49 Augustinegrass grown on St. Johns E soil produced significantly lower root biomass then STA grown on the other four soils during the 27 week establishment period (Table 2 4). No significant soil treatment effect was observed on STA shoot counts collected at the 9 week harvest ( P > 0.05 Figure 2 6 ). However, at the 27 week harvest, no statistical differences on shoot counts were determined for STA grown on the Myakka Bh1, Pomello Bh, St. Johns Bh, and Paola BW soils but STA grown on the Myakka Bh1 and Paola Bw soils did produced significant more shoots than STA grown on the St. Johns E soil (Figure 2 6 ). Shoot counts were highly correlated ( r = 0.76 P = 0.0002) to root biomass at 27 WAP. Tissue Nutrient Conten t Total TKN content of STA clippings collected from 0 to 9 WAP, ranged from 32.8 mg in clippings collected from the Myakka Bh1soil to 54.3 mg for clippings collected from the Paola Bw soil (Table 2 5). The total P content of STA clippings collected during the 9 week establishment study ranged from 4.5 mg for the Myakka Bh1 soil to 9.1 mg for the Pomello Bh soil ( Table 2 5). Total K content of STA clippings collected from 0 to 9 WAP, ranged from 38.7 mg for the Myakk a Bh1 soil to 61.2 for the Paola Bw soil ( T able 2 5). Total TKN content of STA clippings collected from 10 to 27 WAP, ranged from 71.1 mg for the St. Johns E soil to 106 mg for the St. Johns Bh soil ( Table 2 5). Total P content of STA clippings collected from 10 to 27 WAP, ranged from 4.1 mg in cli ppings collected from the St. Johns E soil to 19.7 mg in clippings collected from the Pomello Bh soil (Table 2 5). Total K content of STA clippings ranged from 71.0 mg from the St. Johns E soil to 105 mg from the St. Johns Bh soil for clippings collected f rom 10 to 27 WAP (Table 2 5).

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50 The P and K concentrations of STA clipping tissues (Table 2 8) were within the sufficiency ranges for N (20 to 30 gkg 1 ), P (1.5 to 5 gkg 1 ) and K (10 to 30 gkg 1 ) reported by Broschat and Elliot (2004) Mills and Jones Benton Jr. (1996) and Sartain (2012) with the exception of clipping P content collected at 27 WAP from STA grown on the St Johns E and St. Johns Bh soils (Table 2 8), which were slightly under this range indicating possible P deficiency. Tissue TKN contents for STA grown on all soil treatments were slightly below the sufficiency range indicating possible N deficiency as well However, TKN values do not necessarily represent the total N content of the clippings since not all forms of N are converted to the ammonium form during the procedure (Mills and Benton Jones Jr 1996) No significant soil treatment effect was determined for pelt tissue total TKN, P, or K contents for pelts harvested at 9 WAP ( P > 0.05 Table 2 7). However, there was a significant soil treatment effect on pelt tissue total P content for pelts harvested at 27 WAP; but none for total TKN and K content harvested at 27 WAP (Table 2 7). No statistical differences were determine d for pelt tissue total P contents of STA grown on the Myakka Bh1, Pomello Bh, and Paola Bh soils but pelt tissue total P contents of STA gown on the Pomello Bh soil were significantly higher than STA grown on the St. Johns Bh and St. Johns E soils harvest ed at 27 WAP (Table 2 7). No significant soil treatment effect was determined for root tissue total P or TKN contents collected at 9 WAP ( P > 0.05 Table 2 8). No statistical differences were determined for root tissue total TKN contents of STA grown on t he St. Johns Bh and Paola Bw soils at the 9 week harvest however root tissue total TKN contents of STA

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51 grown on the St. Johns Bh were significantly higher than root tissue total TKN content of STA grown on the Myakka Bh1, Pomello Bh, and St. Johns E soils (Table 2 8). There was a significant soil treatment effect determined for root tissue total TKN, P, and K contents collected at 27 WAP (Table 2 8). No statistical difference was determined for root tissue total TKN content of STA grown on the Myakka Bh1, Pomello Bh, St. Johns Bh, and Paola Bw soils but STA grown on the Myakka Bh1, St. Johns Bh, and Pao la Bw had significantly higher root tissue total TKN contents than STA grown on the St. Johns E soil at 27 WAP (Table 2 8). The root tissue total P contents of STA grown on the Myakka Bh1, Pomello Bh, and Paola Bw soils were not statistically different but the root tissue total P contents of STA grown on the Pomello Bh and Paola Bw soils were significantly higher than STA gown on the St. Johns Bh and St. Johns E soils at 27 WAP (Table 2 8). The root tissue total K content of STA grown on the Myakka Bh soil was significantly higher than STA grown on the Pomello Bh and St. Johns E soils but not statistically different than the root tissue total K content of STA g rown on the St. Johns Bh and Paola Bw soils at 27 WAP (Table 2 8). Clipping total P content was highly correlated to soil P M3 ( r = 0.91, P = 0.03) PSR M3 ( r = 0.94, P = 0.02), and DPS M3 ( r = 0.94, P = 0.02) concentrations for c lippings collected during th e 9 week study. Soil P M3 PSR M3 and DPS M3 values had similar linear relationships ( r = 0.63, P = 0.004) to pelt tissue total P contents during the 27 week study while soil WSP was less correlated ( r =0.52, P = 0.02) to pelt tissue total P contents. Root tissue total P contents of STA were highly correlated to soil P M3 ( r = 0.72 P = 0.0005) PSR M3 ( r = 0.76 P = 0.0002), DPS M3 ( r = 0.75 P = 0.0002) and WSP ( r = 0.65 P = 0.003) values at 27 WAP.

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52 Discussion The high concentrations of OM and Al M3 couple d with low pH values observed in the three Bh horizon soils were expected because Spodosols are characterized by accumulation of organically bo u nd metals (i.e., Al and Fe) (Deconinck, 1980) The high OM concentrations of the three Bh samples indicate that other mass losses may be contributing to the LOI measurement s (e.g., dehydroxylation). The large difference in pH values of the non Bh horizons from the initial to the 9 and 27 week harvest dates may be contributed to the lower buffering capacity of these soils than compared to the Bh horizon soils. There was a wide range in P M3 concentrations between the five soil samples Based on soil P test results a homeowner would be required to follow P restrictions outlined in the urban fertilizer turf rule and no additional P beyond what is stated for the one time starter fertilizer application would be allowed for the first year on the Pomello Bh and Paola Bw soils. The significantly higher PSR M3 and DPS M3 values of the Pomello Bh and Paola Bw soils than of the other three soils suggest that the Pomello Bh and Paola Bw soils are more P saturated than the other three soils and could be potential P sources to the turfgrass. Nair et al. (2004) reported a PSR M3 threshold value of 0.08 for sandy surface horizon s while Chakraborty et al. (2011a) reported a PSR M3 threshold value of 0.09 for Bh horizons in Florida. These threshold values represent a change point value at which WSP concentrations start to rapidly increase with increasing PSR values. PSR M3 values above these thresholds may result in added P being los t easily from the soil through leaching (Chakraborty et al., 2011a) If we compare our PSR M3 values to these findings, our Pomello Bh and Paola Bw soil would be considered higher than the change points

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53 and the remaining three soils (Myakka Bh1, St. Johns Bh, and St. Johns E) would be lower than the reported change points. Usually higher PSR M3 and DPS M3 values correspond to higher WSP concentrations (Nair et al., 2004) and more WSP could lead to higher plant available P. However, the Paola Bw, which had the highest DPS M3 value of 31.0% had similar WSP 1 ) concentrations to the Myakka Bh1 (WSP 1 ) which had a lower DPS M3 value of 0.8 7% at 9 WAP. The Myakka Bh1 and St. Johns Bh soils had similar WSP concentrations to the Paola Bw soil despite having significantly lower soil DPS M3 values at 27 WAP. The comparable WSP concentrations of the lower DPS M3 and PSR M3 Myakka Bh1 and the St. Joh ns Bh soils to the higher PSR M3 and DPS M3 Paola Bw soil may be attributed to the presence of organically complexed P released the Bh soils. The dark color of the drainage water collected from the Myakka Bh1 soil support the hypothesis of this soil WSP consisting of dissolved or colloidal organica lly complexed P. Dissolved OM is darkly colored and contains C N P and some metals (Wright and Reddy, 2012) Fox et al. (1990) indicated that dissolved organic P that was released from Bh horizons may be a significant component of plant available P in Florida Bh horizons. In general, soil s with the higher P M3 soil values (Paola Bw and Pomello Bh soils) produced STA pelt and root tissues with the high est total P contents at the 27 week harvest. However, the Myakka Bh1 soil with significantly lower P M3 ha d comparable pelt and root tissue total P contents to the significantly higher P M3 Pomello Bh and Paola Bw soils at the 27 week harvest. McCray et al. (2012) showed M3 to be a better indicator of plant available P than WSP for Saccharum spp. (sugarcane) grown on organic soils in

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54 southern Florida. Fageria et al. (1988) reported that soil test P concentration was strongly correlated to P content in soils. Liu et al. (2009) reported that both soil WSP and P M1 concentrations were closely correlated to tissue P concentrations in STA (P M3 was not tested). Our results suggest that both soil WSP an d P M3 influenced pelt and root tissue total P contents at the 27 week harvest. The lack of soil treatment effect on pelt and root tissue total P contents harvested at 9 WAP may be attributed to the relatively short establishment period of the turf, with i nitial P fertilizer inputs providing adequate nutrients over the short term Differences in pelt tissue and root tissue total P contents determined at 27 WAP were likely d ue to soil chemical properties effecting P bioavailability since P was only applied d uring the first fertilizer application at 30 DAP. Liu et al. (2006) reported a P deficiency value, based on visual symptoms, for STA tissue as anything less than 1.0 gkg 1 with a minimum P tissue concentration of 0.45 gkg 1 to keep STA alive. Clipping P contents collected from all soil treatme nts were above 1.0 gkg 1 for the entire 27 week study and no visual symptoms for P deficiencies were observed for turfgrass grown on any soil. This supports findings by Liu et al. (2008) who noted that with no P application to STA and very low soil P concentrations it took almost one year to induce P deficiency. Liu et al. (2008) findings coupled with our results suggest that STA could be sustained for at least 6 month to a year with very low soil P concentrations. The lack of soil treatment effect on pelt tissue total TKN and K (at 9 and 27 WAP) and root tissue K contents harvested at 9 WAP, may be attributed to adequate nutrients

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55 obtained from fertilizer inputs throughout the whole study period. Any differences in root tissue total TKN at 9 and 27 WAP and root tissue K at 27 WAP wer e likely attributed to differences in biomass production, since these nutrient parameters were high ly correlat ed with biomass weights. The lack of soil treatment effect on STA clipping and pelt biomass and shoot counts collected during the first 9 WAP may be attributed to the relatively short establishment period of the turfgrass and the soils natural ability to provide ample nutrients and water over the short term. Differences determined in STA clipping and pelt biomass es at 27 WAP support the idea that th e establishment periods may be longer for STA grown on different soil types. At 27 WAP, there were significant differences in pelt TKN and P, but no trends emerged showing a single soil treatment having significantly higher contents of all three nutrients. Differences in root biomass between soil treatments collected at 9 and 27 WAP may be attributed to the high correlation between root biomass and root tissue total TKN contents. The significantly lower root biomass of STA grown on the St. Johns E soil at 27 WAP may be the factor controlling the lower shoot count of turfgrass harvested from the St. Johns E soil. Less roots bio mass could result in less nutrient uptake, therefore limiting new shoot growth. Carrow (1989) showed that root growth can be affecte d by the amount of leaf area per unit of sod, with greater green lea f area producing more carbohydrates for root growth which support the high correlation between root mass and shoot counts reported for our study at 27 WAP. Differences in SPAD readings can likely be attributed to turfgrass blade TKN concentrations H igher blade TKN concentrations may have produced higher tissue

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56 chlorophyll levels resulting in higher SPAD readings. However, STA nutrient clippings concentration s represent ed a composite of clippings collected over the whole 9 week study period and from 10 to 27 WAP ; therefore, statistical analysis could not be completed Soil EC values were extremely low for all soil treatments across the entire 27 week study (da ta not shown). Camberato (2001) observed a upper salt tolerance limit of >1.0 S m 1 for STA, while Miyamoto et al. (2004) reported the salt tolerance of STA range from 0.8 to 1 S m 1 of soil EC Therefore, salts had no effect on turfgrass growth or quality in our study. The significantly higher soil moisture content of the St. Johns Bh soil may be due to the significantly higher OM content when compared with the St. Johns E and Paola Bw soils. However, the St. Johns Bh soil had lower OM content then the Myakka Bh1 and the Pomello Bh. The higher moisture content observed in the St. Johns Bh soil compared to the Pomello Bh may be attributed to the lower bulk density of the St. Johns Bh soil. The Myakka Bh1 had lower bulk density and higher OM content then the St. Johns Bh soil so differences in the moisture content may be attributed to formation of preferential flow pathways in the Myakka Bh1 soil or differences in mineral pore sizes between the two soils. Based on our results, the chemical properties of spodic derived fill materials had litt le effect on the establishment STA. G eneral trends emerging towards the end of the 27 week establishment study show overall higher quality STA growing in the Myakka Bh1 and the Paola Bw soils than compared to the St. Johns E soil, but no differences in qua lity for STA grown on the Pomello Bh and St. Johns Bh soils. With the small amount of P fertilizer added to the soils during the 9 and 27 week studies, the ability of the fill

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57 materials to retain P for the turfgrass uptake was likely an important factor i n producing quality turfgrass. The low quality of STA grown on the St. Johns E soil may be attributed to the relatively inert chemical properties and low OM content of the St. Johns E soil. The low pH and high concentrations of Al and Fe in the Bh soils did not seem to effect P bioavailability to turfgrass in the short term. In fact, the comparable WSP values of some of the lower P M3 Bh horizons to the higher P M3 non Bh horizon supports the idea that Bh horizons may be able to provide plant availab le P to turfgrass by the release from organically complexed P. Soil P status alone was not a good predictor of visual turfgrass quality ratings, as other factors may have influenced total quality. However soil P status, particularly P M3 and WSP, was a good predictor of turfgrass tissue P contents. In general, the two soils with the higher P M3 and WSP values produced turfgrass tissue with the higher clipping P content. Soil DPS M3 and PSR M3 values were not good indicators of P content in t urfgrass tissue as some lower DPS M3 value Bh s amples were able to produce comparable WSP values which may have led to higher plant available P. P hosphorus deficiency would be expected to develop in turfgrass planted on the St. Johns Bh and St. Johns E soil s if the study time was extended. However, since these soils tested in would be allowed additional P fertilization beyond what is outlined in the urban fertilizer turf rule. The two soils (Pomello Bh and Paola Bw) testing amount of P allowed to be added. However, these soils had the highest tissue P contents of all the soil treatments and possible P deficiency would not be likely for some time. Thus, the urban fertilizer turf rule is not expected to limit newly established quality

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58 and growth of STA grown on low or high PSR M3 or DPS M3 Bh or non Bh soils. However, this study only examined a few soil types that fell into two soil P test categ In addition, only 2 of water soluble P fertilizer was added at the beginning of the study which likely influenced turfgrass P tissue contents This study did not document any major effects of spodic derived fill materials on the establishment of STA during the 27 week study period However, different trends may emerge if the turfgrass was grown for longer periods. The low pH found in most Bh horizons may limit P bioavailability to the turfgrass in post establishment periods and could also affect the bio availability of other important turfgrass micronutrients not tested for in this study. Future studies need to include a wide range in soil test P status of Bh and non Bh fill materials and look at eff ects of soil types on post establishment periods conducted in field plots Future studies should also include adequate P inputs based on soil tests recommendations throughout the study period to see if P deficiencies that arise are solely due to soil prope rties that limit P bioavailability and not to the lack of P fertilizer inputs.

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59 Table 2 1 Irrigation schedule for st augustinegrass establishment in soil columns in a production house in Wimauma FL. Date DAP z Depth per irrigation event ( centimeter ) Number of events Irrigation event Timing 11 May 2011 0 0.84 1 1600 HR 12 14 May 2011 1 3 0. 84 2 1600 HR 15 17 May 2011 4 6 0. 84 3 0900 HR / 1600 HR 18 24 May 2011 7 13 0. 69 3 0800 HR / 1200 HR / 1600 HR 25 May 2011 1 4 0 .00 0 y 26 31 May 2011 1 5 20 0. 69 2 0900 HR /1600 HR 1 June 2011 21 0. 69 1 0800 HR 2 8 June 2011 21 28 0. 84 1 0800 HR 9 June 2011 29 0 .00 0 N/A 10 June 2011 30 0. 84 1 0800 HR 11 June 2011 31 0 .00 0 N/A 12 June 2011 32 0. 84 1 0800 HR 13 June 2011 33 0 .00 0 N/A 14 June 2011 34 0. 84 1 0800 HR 15 June 2011 35 0 .00 0 N/A 16 June 2011 36 N D x 1 0800 HR 17 19 June 2011 37 39 0 .00 0 N/A 20 June 2011 40 0. 97 1 0800 HR z DAP = D ays after planting. y = Value not measured for that event x ND = N ot determined due to a power outage to automatic timing system that resulted in unknown application amount of water Table 2 2 Mean initial b ulk densit y of Florida fill materials used in soil columns to evaluate st augustinegrass growth and quality response to soil properties. Soil series an d horizon 3 ) Myakka Bh1 1.20 c Pomello Bh 1.34 b St. Johns Bh 1.24 c Paola Bw 1.56 a St. Johns E 1.58 a

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60 Table 2 3. Mean selected chemical properties of Florida soil fill materials used in a column study to evaluate st augustinegrass growth and quality response to soil properties at 0, 9, and 27 weeks after planting Harvest date and soil m aterial pH O rganic matter (gkg 1 ) Mehlich 3 Ca (mgkg 1 ) Mehlich 3 Fe (mgkg 1 ) Mehlich 3 Al (mgkg 1 ) Mehlich 3 P (mgkg 1 ) Water soluble P ( m g kg 1 ) PSR z DPS y (%) 0 weeks after planting Myakka Bh1 4.1 67.5 333 27.6 988 <12.5 0.45 0.004 0.69 Pomello Bh 4.3 60.6 14.2 <5.0 x 1593 193 1. 3 0.105 19.12 St. Johns Bh 4.1 41.6 14.1 37.3 1481 <12.5 0 .00 0.006 1.0 Paola Bw 5.3 3.8 24.2 60.9 643 123 0.03 0.159 28.97 St. Johns E 5. 8 1.6 29.3 <5.0 145 <12.5 0 .00 0.026 4.73 9 weeks after planting Myakka Bh1 4.1 c y 67.6 a 356 a 36.6 c 1138 c <12.5 c 0.84 bc w 0.004 d 0.87 d Pomello Bh 4.5 b 61.2 a 42.4 b < 5.0 d 2406 a 339 a 2.8 a 0.123 b 22.3 b St. Johns Bh 4. 5 b 39.1 b 71 .0 b 68.6 b 1962 b <12.5 c 0.13 d 0.003 e 0.5 0 e Paola Bw 6.9 a 3.0 c 51.2 b 148 a 737 d 158 b 0.8 9 b 0. 171 a 31.0 a St. Johns E 6. 8 a 2.2 d 62.2 b < 5.0 d 171 e <12.5 c 0.26 cd 0.031 c 5.7 c 27 weeks after planting Myakka Bh1 4.0 b 66.1 a 330 a 32.7 c 1121 c <12.5 d 0.24 bc 0.005 e 0.87 e Pomello Bh 4.5 b 69.0 a 65.7 b <5.0 d 2172 a 313 a 2.5 a 0.126 b 22.8 b St. Johns Bh 4.4 b 37.8 b 94.1 b 58.8 b 1862 b 18.1 c 0.16 bc 0.009 d 1.5 d Paola Bw 6.8 a 3.00 c 89.7 b 73.6 a 591 d 125 b 0. 59 b 0. 174 a 31.6 a St. Johns E 6.6 a 2.30 c 87.1 b <5.0 d 155 e <12.5 d 0.14 c 0.036 c 6. 4 c z Phosphorus saturation ratio. y Degree of phosphorus saturation. x Less then the detection limit of inductively couple d plasma atomic emission spectroscopy w M ean ant difference test at P

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61 Table 2 4. Mean biomass of clippings, pelts, and roots of st. augustinegrass grown on different Florida soil fill mat erials in a soil column study. Harvest date and soil material Clipping biomass (g) Pelt biomass (g) Root biomass (g) 9 week harvest M yakka Bh1 0.10 a z 47.9 a 2.29 b Pomello Bh 0.1 3 a 46.3 a 2.65 b St. Johns Bh 0.1 5 a 37.1 a 4.92 a Paola B w 0.1 4 a 41.4 a 3.32 ab St. Johns E 0.1 6 a 44.2 a 2.90 ab 27 week harvest Myakka Bh1 0.2 5 a 61.0 a 8.58 a Pomello Bh 0.26 a 45.8 a 7.72 a St. Johns Bh 0.2 6 a 49.7 a 7.13 a Paola B w 0.2 6 a 51.0 a 8.50 a St. Johns E 0.16 b 46.2 a 3.25 b z Mean P 0.05. Table 2 5. Mean total nutrient content of clippings from st. a u gustinegrass grown on five different Florida soil fill materials collected from 0 to 9 and 10 to 27 weeks after planting. Collection period and soil material Total TK N (mg) Total P (mg) Total K (mg) 0 to 9 weeks after planting Myakka Bh1 32.8 4.5 38.7 Pomello Bh 45.6 9.1 51.0 St. Johns Bh 52.4 5.5 52.9 Paola Bw 54.3 8.7 61.2 St. Johns E 44.1 5.3 48.4 10 to 27 weeks after planting Myakka Bh1 92.2 12.2 99.4 Pomello Bh 95.2 19.7 88.6 St. Johns Bh 106 6.9 105 Paola Bw 81.6 16.6 95.4 St. Johns E 71.1 4.1 71.0

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62 Table 2 6. Mean nutrient concentrations of clippings from st. augustinegrass grown on five different Florida soil fill materials collected from 0 to 9 and 10 to 27 weeks after planting. Harvest date and soil material TKN (gkg 1 ) P (gkg 1 ) K (gkg 1 ) 9 week harvest Myakka Bh1 12.9 1.78 15.3 Pomello Bh 13.9 2.79 15.6 St. Johns Bh 13.8 1.45 13.9 Paola B w 15.3 2.45 17.2 St. Johns E 13.1 1.58 14.4 27 week harvest Myakka Bh1 13.2 1.75 14.2 Pomello Bh 13.7 2.82 12.7 St. Johns Bh 15.7 1.03 15.7 Paola B w 12.3 2.51 14.4 St. Johns E 17.8 1.02 17.7 Table 2 7. Mean total nutrient content of pelts from st. augustinegrass grown on five different Florida soil fill materials collected at the 9 and 27 week harvest date. Establishment period and soil material Total TK N (mg) Total P (mg) Total K (mg) 9 week harvest M yakka Bh1 303 a z 43.3 a 243 a Pomello Bh 331 a 49.6 a 258 a St. Johns Bh 242 a 30.7 a 191 a Paola Bw 290 a 43.4 a 199 a St. Johns E 287 a 32.5 a 192 a 27 week harvest Myakka Bh1 362 a 51.0 ab 243 a Pomello Bh 318 a 58.2 a 223 a St. Johns Bh 422 a 38.5 bc 266 a Paola Bw 354 a 56.4 ab 253 a St. Johns E 387 a 34.3 c 217 a z P 0.05.

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63 Table 2 8. Mean total nutrient content of roots from st. augustinegrass grown on five different Florida soil fill materials collected at the 9 and 27 week s after planting Establishment period and soil material Total TK N (mg) Total P (mg) Total K (mg) 9 weeks after planting Myakka Bh1 16.5 b z 1.4 a 6.9 a Pomello Bh 15.7 b 2.4 a 6.3 a St. Johns Bh 29.1 a 2.5 a 13 .0 a Paola Bw 19.8 ab 2.7 a 15.1 a St. Johns E 16.3 b 1.8 a 13.5 a 27 weeks after planting Myakka Bh1 41.3 a 3.5 ab 35.1 a Pomello Bh 31.4 ab 4.8 a 25.0 bc St. Johns Bh 40.9 a 2.7 bc 26.1 abc Paola Bw 40.5 a 4.9 a 27.3 ab St. Johns E 25.7 b 1.5 c 17.8 c z P 0.05.

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64 Figure 2 1 Mean weekly soil volumetric water content of Florida soil fill materials used in a column study to evaluate st. augustinegrass growth and quality response to soil properties collected over 9 and 27 week establishment study periods. Values within the establ ishment period with the same letter are not significantly different at P test.

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65 Figure 2 2 Mean weekly visual quality ratings from 0 to 9 weeks after planting of st. augustinegrass grown in Florida soi l fill materials. Visual ratings use a scale from 1 to 9, with 1= dead, brown turf; 6= minimally acceptable turf; and 9= highest quality turf. No significant difference ( P > 0.05) was observed between soi l treatments during the first 9 weeks after planting

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66 Figure 2 3 Mean visual quality ratings of st. augustinegrass grown in Florida soil fill materials at 11, 12, 15, 17, 25, and 27 weeks after planting (WAP) Visual ratings use a scale from 1 to 9, with 1= dead, brown turf; 6= minimally acceptable turf; and 9= highest quality turf. Values within the same sampling date with the same letter are not significantly different at P < 0.05 using

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67 Figure 2 4 Mean SPAD meter readings for st. augustinegrass grown in F lorida soil fill materials at 5, 8, and 9 weeks after planting (WAP). Values within the same sampling date with the same letter are not significantly different at P < 0.05

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68 Figure 2 5 Mean SPAD meter re adings st. augustinegrass grown in Florida soil fill materials during a 27 week establishment study. Values with the same letter are not significantly different at P difference test.

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69 Figure 2 6 Mean shoot counts of st. augustinegrass grown in Florida soil fill materials at 9 and 27 week s after planting Values within the same harvest date with the same letter are not significantly different at P significant differen ce test.

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70 CHAPTER 3 L EACHING OF PHOSPHORUS FROM ST. AUGUSTINEGRASS ESTABLISHED ON SPODIC FILL MATERIAL S Introduction Water quality degradation is a major problem for many fresh surface water bodies throughout the U.S. ( Soldat and Petrovic 2008) Since phosphorus (P) is often the limiting nutrient for algal and aquatic weed growth in freshwater bodies, P enrichment from point and non point sources has been long been considered the leading cause of freshwater quality issues (e.g. harmful algal blo oms, eutrophication, and dead zones) (Anderson et al., 2002; Correll, 1998; Riegman, 1995; Sharpley et al., 2003; Smith 1983) When P concen trations in freshwater bodies become elevated beyond natural levels they can stimulate large algal blooms, which result in decreased oxygen supplies to other aquatic biota. Since P is an essential element for proper crop and plant growth, it is often inclu ded in fertilizer regimes for agricultural crops and lawns in urban areas ( Chakraborty et al., 2011a; Liu et a l ., 2008) Both agricultural and urban areas have been identified as the two most important contributors to nonpoint source nutrient enrichment o f surface water ( Carpenter et al., 1998; Hartman et al., 2008; Sharpley et al., 2003) A considerable amount of researc h has focused on nutrient losses from agricultural areas, with less work evaluating nutrient losses from urban areas (Soldat and Petrovic 2008) Phosphorus leaching has traditionally been considered a minor pathway of P losses from agricultural soils ( Sims et al., 1998) because P is very reactive in the soil solution environment and most soils have relatively high P sorption capacities. However soils with low P sorption capacities that are fertilized and soils with elevated P

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71 levels (natural or due to repeated applications of P) have the potential to leach P below the root zone ( Heckrath et al., 1995; Hongthanat et al., 2011; Schwab and Kulyingyong, 1989; Soldat and Petrovic, 2008) uncoated acidic soils are prone to leaching due to the absence of iron ( Fe ) or aluminum (Al) (hydr) oxide coat ings that are capable of retaining p hosphate ions by forming surface bonds (Harris et al., 1996; Liu et al., 2008; Snyder et al., 2 001) Soil texture can also have a n effect on P concentrations and loads in leachate (Linde and Watschke, 1997; Petr ovic, 2004; Soldat and Petrovic 2008) In a comprehensive review of turfgrass leaching studies, Soldat and Petrovic (2008) reported that P leaching from fine textured soils was generally lower than sandy textured soils. Researchers often use standard agronomic soil tests (e.g., Mehlich 1, Mehlich 3, etc.) to assess the environmental risk of P loss in run off or leachate ( Nair and Harris 2004) However, standard agronomic soil tests do not account for the P retention capacity of the soils. In contrast, measurements such as the degree of P saturation (DPS), the P saturation ratio (PSR), and the soil P storage capacity (SPSC) account for the P re tention capacity of soils by quantifying the relationship between soil P and P retaining soil minerals (mainly Al and Fe) (Chakraborty et al., 2011a; Maguire and Sims, 2002 ; Nair et al., 2004) Linear relationships between soil WSP concentrations or from the soil to solution abruptly increases (Chakraborty et al., 2011a; Nair et al., 2004; Sims et al., 2002) In contrast, the soil SPSC indicates how much P can be added to a soil before critical PSR or DPS threshol ds are reached ( Chakraborty et al., 2011a) These soil tests can more

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72 accurately assess soil P saturation status and can provide environmental P risk assessment s for acidic soils. However, DPS, PSR, and SPSC measurements are not appropriate for calcareous or high pH soils, since P absorption and retention is not di rectly related to extractable Al and Fe in those soil types. Instead, t he dominant forms of P in neutral and calcareous soils are calcium (Ca) P minerals or P adsorbed to the surfaces of clay minerals and Ca carbonates ( Havlin et al., 2005) Urban soils and fill materials have been shown to have widely varying physical and chemical properties when compared to neighboring native soils (Pouyat et al., 2007; Scharenbroch et al., 2005; Short et al., 1986) Cha kraborty et al. (2011a) showed that the P storage capacities of surface horizons are typically lower than Bh horizons and that Bh horizons generally act a s potential P sinks. Spodic horizons are characte rized by having large quantities of Al and Fe associated with carbon, which when coupled with low pH values give them the ability to sorb large portions of P (Chakraborty et al., 2011a; Deconinck 1980) Spodosols represent the largest soil order in Florida for land coverage ( Collins, 2010; Stone et al., 1993) ; therefore, it is likely that some of these Bh horizons collected from Spodo sols will end up as fill materials. These Bh horizons may have large stores of P that could become a potential P source when Bh derived soils are applied as fill materials. Other fill materials may contain low concentrations of P values initially and have little capacity to assimilate additional P ; these soils may quickly become potential environmental risk when applied as fill materials In addition, t urfgrass is a dominant component of pervious surfaces in urban landscapes ( Milesi et al., 2005) that requires significant fertilizer and water inputs to maintain a healthy and functional turf stand. I t is important to understand how the initial P statuses of different soil fill

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73 materials and their remaining P sorption capacity can affect the leaching of P form urban areas Therefore, t he objective of this study was to quantify the P leaching from Bh a nd non Bh derived fill materials. Materials and Methods S ite Locations and Soil Sampling Five subsoils were obtained from two different geographical locations in Florida. Two soil samples were collected from an active borrow pit located 20 km southeast of Jacksonville, FL. Soils were removed from the ground by backhoe operations prior to our sampling. One soil was collected from the Bw horizon of a Paola sand (Hyperthermic, u ncoated Spodic Quartzipsamments) ( Soil Survey Staff 2010) The second soil was collected from a Bh horizon of a Pomello fine sand (Sandy, siliceous, hyperther mic Oxyaquic Alorthod) ( Soil Survey Staff, 2010) Soil was also collected from a new residential housing development located east of Fruit Cove, FL. Various soil horizon s were exposed in a circular trench that was excavated prior to sampling. The exposed Bh and E horizons of a St. Johns sand (Sandy, siliceo us, hyperthermic Typic Alaquods) ( Soil Survey Staff 2010) were collected. An additional soil sample was collecte d near Labelle, FL at a private cattle farm dominated by pine flatwoods vegetation. A small circular soil pit was hand dug using a shovel. Soil was excavated from the Bh1 horizon of a Myakka sand (Sandy, siliceo us, hyperthermic Aeric Alaquods) ( Soil Surve y Staff 2010) Soil samples were air dried at 25 2C for 10 d and sieved to pass a 2 mm screen. Experimental Design The experiment was conducted inside a sawtooth production house at the University of Florida Institute of Food and Agricultural Scie nces (UF IFAS) Gulf Coast

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74 Research and Education Center in Wimauma, FL. Forty soil columns were constructed by cutting polyvinyl chloride (PVC) pipe ( 15.2 cm internal diameter) into 30.5 cm long sections. Forty 15.2 cm diameter endcaps were filled with thr ee pieces of cheesecloth that had been cut into 15.2 cm circular pieces and chalked to the bottom of each endcap. A mixture of deionized water washed sand (186 g) and pea gravel (614 g) was added to each endcap to allow for free drainage of water and to he lp prevent soil loss from the column. Endcaps were then attached to the bottom of each PVC column and water resistant caulk was applied to the outside and inside lips of the endcap to prevent water leakage. A 1.3 cm hole was drilled into the center of each endcap to allow for water drainage. The five excavated air dried soils were packed into eight PVC columns; four columns containing each soil were used for a 9 week turf establishment study (12 May to 11 July 2011) and four columns for a 27 week turf est ablishment study (12 May to 10 Nov. 2011). Air dried soils were packed into the columns in 1000 g increments by alternating packing with ten taps of a hand made tool (steel rod welded to a 10.2 cm diameter steel circle). The packing tool was moved in a ci rcular pattern in between each tap to ensure the whole column was evenly packed. Packing was performed until the soil level was within a 1.3 cm of the top of the column to allow room for placement of sod. st. augustinegrass (Council Growers, Inc., Ruskin, FL) were cut from sod pallets using a 15.2 cm cup cutter. Soil was gently washed off of the turfgrass roots using a low pressurized hose prior to the installation of sod in the columns. Sod was installed by placing the 6 in ch turfgrass cutouts onto the packed soil

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75 columns and ensuring the top of thatch layer was even with the top of the PVC column walls. Excess turfgrass extending over the edge of the 15.2 cm PVC column was trimmed evenly with the side walls of the column us ing pruning shears. Irrigation and Fertilizer Application Columns were irrigated with potable well water that contained no measurable no measurable molybdate reactive P (MRP, < 0.09 mg L 1 ) ( Pierzynski et al., 2009) using a drip irrigation system that was regulated to 206843 Pa and connected to a sand filtration system. Each turf column was outfitted with two drip emitter stakes (Arrow Dripper; MMXI NetaFim Irrigation, Inc., Fresno, CA) that were placed in the middle of the column; each emitter applied 0.95 L hr 1 of water Irrigation events were scheduled using a n automated timer to ensure that the turf received adequate water for optimal growth. The amount of water applied to each column was determined by following UF IFAS irrigation recommendations for STA in southern Florida (Trenholm et al., 2011; Trenholm e t al., 2006) The irrigation schedule for the first 40 d after planting (DAP) is presented in Table 2 1 At 21 DAP, the two drip emitter stakes were removed from each column and replaced with a single, adjustable spray emitter (Shrubbler 360; Antelco Corp., Longwood, FL) due to concerns of uneven wetting of the soil columns. The spray emitters were adjusted individually until an application rate of 20.8 2.84 L hr 1 of water was achieved for all emitters. From 40 through 82 DAP, the tu rf received 0.97 cm of water twice a week (Monday and Thursday of each week at 0800 HR for a 30 s run time). From 85 DAP until the end of the experiment, turf received 1.02 cm of water twice a week (Monday and Thursday of each week at 0800 HR for a 32 s run time ) The amount of water was increased from 0.97 to 1.02 cm of water because turf showed signs of water stress due to increasing air temperatures in summer.

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76 Soil columns were fertilized with a water soluble 36N 0P 5K fertilizer mix (Miracle Gro Water Soluble Lawn Food; The Scotts Company, LLC, Marysville, OH) that was specifically formulated for lawns. Columns were fertilized at an nitrogen (N) rate of 2.4 g m 2 following UF IFAS recommendations for STA ( Trenholm et al., 2011) During the first fertilizer application (applied 30 DAP), 0.059 g m 2 P was applied as a starter application by dissolving 0.168 g NaH 2 PO 4 into the water soluble fertilizer solution. During subsequent fertilizer applications (approximately every 30 d), no P fertilizer was applied. Fertilizer was applied to the columns by hand using pre measured aliquots (half the volume of irrigation applied) the fertilizer solution. After the fertilizer was applied, the columns were irrigated with the reaming vol ume of water to help move the fertilizer into the soil and prevent foliar burn on the grass blades. Soil Characterization Soil samples were air dried at 25 2C for 10 d and sieved to pass a 2 mm screen. Initial soil bulk density of soil s i n PVC columns were calculated by dividing the oven dried mass of soil packed into columns by the PVC columns area Soil texture was determined using the hydrometer method ( B ouyoucos 1962) Soil organic matter (OM; loss on ignition) and pH (1:2 soil to deionized water ratio) were determined by standard methods of the UF IFAS Analytical Research Laboratory (ARL) in Gainesville, FL ( Mylavarapu 2009) Soil samples were extracted using a modified Mehlich 3 (M3) dilution ratio method (1:7 ratio of soil to 0.2 M CH 3 COOH + 0.25 M NH 4 NO 3 + 0.015 M NH 4 F + 0.013 M HNO 3 + 0.001 M EDTA) ( Baker et al., 2002) Mehlich 3 extracts were analyzed for calcium (Ca M3 ), Fe, Al, and P using inductively couple d plasma atomic emission spectroscopy (ICP AES ) at the ARL i n Gainesville, FL. Soil water soluble phosphorus (WSP) was extracted by following method of Self Davis et al. (2009) and

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77 soluble P in filtrate was determined on a spectrophotometer (Genesys 20; Thermo Fisher Scientific, Madison, WI) at 882 nm following the Murphy and Riley (1962) procedur e. The PSR values for the soils were calculated using the following equation: PSR M3 = P M3 / (Al M3 + Fe M3 ) where P M3 Al M3 and Fe M3 are the concentrations of M3 extractable P, Al, and Fe expressed in mmol kg 1 ( Maguire and Sims 2002) The DPS was calculated using the following equation: DPS M3 = [(P M3 ) / (Al M3 + Fe M3 )] 100, where P M3 Al M3 and Fe M3 are the concentrations of M3 extractable P, Al, an d Fe expressed in mmol kg 1 and is an empirical factor that compares different soils with respect to P saturation ( Nair and Graetz 2002) Soil P storage capacity was calculated using the following equation: SPSC M3 = (change point PSR M 3 soil PSR M3 ) (Fe M3 + Al M3 ) 31, where Fe M3 and Al M3 are the concentrations of Mehlich 3 extractable Al and Fe expressed in mmol kg 1 and the change point PSR M3 is the value at which WSP abruptly starts to increase with increasing PSR M3 (0.09) for 241Bh horizons collected in Florida ( Chakraborty et al., 2011a) At turfgrass harvest [9 and 27 weeks after planting ( WAP )] the soil from each column was removed and air dried at 25 2C for 10 d and sieved to pass a 2 mm screen. All soil samples collected at 9 and 27 week s after planting (WAP) were analyzed for the same parameters as described for the initial soil pa rameters, with the exception of M3 nutrients. Soil samples collected at harvest were extracted using for M3

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78 using the method of Sims (2009b) adopted from Mehli ch (1984) (1:10 ratio of soil to 0.2 M CH 3 COOH + 0.25 M NH 4 NO 3 + 0.015 M NH 4 F + 0.013 M HNO 3 + 0.001 M EDTA). Leachate Collection and Analysis One day prior to the sod installation, 2 82 L of water was applied to each column by pouring water onto the soil at a rate slow enough to avoid ponding. Water was applied to the columns to remove any air in the soil pores and to ensure uniform leaching of the columns. The amount of water that was applied to each column was determined by slowly pouring water onto the soil treatment with the lowest bulk density value until water started to drip out of the bottom of the column. The columns were allowed to drain for 24 h at which tim e the total leachate from each column was measured and recorded. A 125 mL subsample of leachate was collected from each column. An unfiltered portion of the leachate subsample was stored in a 60 mL scintillation vial. The remaining portion of the leachate subsample was filtered through a 0.45 mL scintillation vial. Unfiltered and filtered leachate samples in scintillation vials were stored at 0 2 C until analysis. Following sod application, leachate was measured and collected 24 h after the first daily irrigation event. Leachate samples were combined to create weekly flow weighted composite samples unless the volume of leachate was too small to allow for weekly comp ositing, in which case leachate samples were combined to generate multi week flow weighted composite samples. Filtered (0.45 m) and unfiltered samples were stored in two separate plastic 60 mL scintillation vials at 0 2 C until analysis. Drainage depths (cm) were calculated by divided leachate volumes ( k L) by the area (m 2 ) of the column and multiplying by a factor of 100.

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79 Unfiltered l eachate samples were analyzed for MRP Filtered leachate samples were analyzed for dissolved reactive orthophosphate ( DRP ) and total dissolved P (TDP) ( Pierzynski et al., 2009) Unfi ltered total P samples were not analyzed throughout the experiment due to limited leachate sample volume a nd negligible differences were found when spot checks were performed on filtered and unfiltered samples (mean difference = 0.0 5 mg L 1 standard devia tion of 0. 06 mg L 1 ). Reactive P ( MRP and DRP ) analysis was performed using the molybdate blue method ( Murphy and Riley 1962) on a spectrophotometer (Genesys 20; Thermo Fisher Scientific) at 882 nm. Total dissolved P was extracted from leachate samples following a modified version of EPA method 351.2 for TKN determination of surface waters; a 5 to 1 ratio of leachate sample to digestion solution was used instead of the 2.5 to 1 ratio outlined in the EPA method ( U.S. Environmental Protection Agency 1993) Total dissolved P was analyz ed on a flow segmented analyzer (Astoria 2 Analyzer; Astoria Pacific International, Clackamus, OR) at the ARL in Gainesville, FL. Nutrient load calculations for MRP DRP and TDP composite samples were determined by multiplying P concentrations (mg L 1 ) by the total volume (L) of leachate collected over the time period of the composite sample. Turfgrass Root Biomass Turfgrass was harvested from 20 columns at 9 WAP and from the remaining 20 columns at 27 WAP, by sliding a knife blade around the edges of the PVC columns and inverting the column to allow the turfgrass and soil to slide out onto a tray. Turfgrass roots were placed in a 2 mm sieve and any remaining soil was washed off under gently flowing water. The wet roots were then wrapped in a paper towel an d dried to a constant mass at 41 2C, prior to being weighed.

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80 Data Analysis The experiment was designed as a completely randomized design with five soil treatments. Each soil treatment was randomly assigned to the columns, with eight replications for eac h treatment for the 9 week establishment period, a nd four replications for the 27 week establishment period for leachate analysis. Each soil treatment was randomly assigned to the columns, with four replicatio ns for each treatment for the 9 week establishm ent period, a nd four replications for the 27 week establishment period for soil analysis. Soil samples with concentrations of P M3 and Fe M3 below the detection limit were assigned a value of half the detection limit. Soil treatment effects on soil propertie s and root biomass were analyzed using the PROC MIXED procedure in SAS 9.3 with soil treatment as a fixed effect and replicate as a random effect ( SAS Institute 2012) Normality was checked by examining histogram s and normality plots of the conditional residuals. Soil P M3 and Fe M3 PSR M3 DPS M3 and soil OM (9 week harvest only) were log transformed prior to statistical analysis. Soil P M3 and Al M3 PSR M3 and DPS M3 (27 week harvest only) were log transformed prior to statistical analysis. Relationships between soil and leachate parameters were determined using a Pearson correlation analyzed by the PROC CORR procedure in SAS 9.3 (SAS Institute 2012) Leachate volumes, MRP DRP and TDP concentrations and loads were analyzed by week due to an overall significant soil treatment week interaction. All comparisons were completed u significant level of = 0.05.

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81 R esults Soil Properties The initial bulk densities of the Paola Bw and St. Johns E soils were significantly higher than the other three soil s (Table 2 2 ). The soil textu ral class of all five soils was sand (data not shown). The initial OM contents of the three Bh soils (Pomello, St. Johns, and Myakka) were above 41.6 gkg 1 ; the St. Johns E and Paola Bw soils had OM contents were less than 3.80 gkg 1 (Table 3 1 ). The soi l OM contents of the Myakka Bh1 and Pomello Bh soils were not statistically different, but both were significantly higher than the OM contents of the St. Johns Bh, Paola Bw, and St. Johns E soil at the 9 and 27 week harvest date (Table 3 1 ). The pH of the initial soil samples ranged from 4.1 to 5.8, with a median pH of 4.7 (Table 3 1 ). All soils were acidic, but the three Bh horizon soils (Pomello, St. Johns, and Myakka) had significantly lower pH than compared to the pH of the St. Johns E and Paola Bw soils at the 9 and 27 week harvest (Table 3 2). The initial Ca M3 concentrations ranged from 14.1 mg kg 1 in the St. Johns Bh soil to 333 mg kg 1 in the Myakka Bh1 soil (Table 3 1 ). The Maykka Bh1 soil had significantly higher Ca M3 concentrati ons than the other four soils at the 9 and 27 week harvest date (Table 3 1 ). The Paola Bw soil had the highest initial Fe M3 concentration of all soils while the Pomello Bh and St. Johns E soils had initial Fe M3 concentrations below the detection limit (< 5.0 mg kg 1 ) for soils at the beginning of the experiment (Table 3 1 ). The Paola Bw soil had significantly higher Fe M3 concentrations than the other four soil s at the 9 and 27 week harvest dates (Table 3 1 ). The three Bh soils (Myakka, Pomello, and St. Jo hns) had significantly higher Al M3 concentrations than the Paola Bw and St. Johns E soils (Table 3 1 ), with the Pomello Bh soil having the highest Al M3 concentrations at the 9 and 27 week harvest (Table 3 1 ). Initial soil P M3

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82 concentrations ranged from < 12.5 to 193 mgkg 1 with the Pomello Bh and Paola Bw soil treatments containing the highest P M3 concentrations of the soil s ; the Myakka Bh1, St. Johns E, and St. Johns Bh soils had P M3 concentrations below the detection limit (12.5 mg kg 1 ) (Table 3 1 ). S imilar trends were determined for soil P M3 concentrations at the 9 and 27 week harvest (Table 3 1 ). Initially the Pomello Bh soil had the highest WSP concentrations of all the soils, while both St. Johns soils contained no detectable WSP (detection limit = 0.088 mg L 1 ) (Table 3 1 ). The Pomello Bh soil had significantly higher WSP concentrations then all other soils at both the 9 and 27 week harvest dates (Table 3 1 ). Initially, both the Pomello Bh and Paola Bw soil s had PSR M3 values over 0.1, while the r emaining soil s had PSR M3 values all below 0.031 (Table 3 1 ). The Paola Bw soil had significantly higher PSR M3 values then the other four soils at 9 and 27 week harvest (Table 3 1 ). Similar trends between PSR M3 and DPS M3 values were reported for soils at planting and at the 9 and 27 week harvest dates (Table 3 1 ). Nair et al. (2004) reported a PSR M3 threshold value of 0.08 for sandy surface horizons while Chakraborty et al. (2011b) reported a PSR M3 threshold value of 0.09 for Bh horizons in Florida. These threshold values represent a change point value at which soil WSP and leachate P concentrations start to rapidly increase with increasing PSR values ( Chakraborty et al., 2011a; Nair et al., 2004) Soil PSR M3 values above these thresholds may result in added P being lost easily from the soil through leaching ( Chakraborty et al., 2011b) If we compare our PSR M3 values to these findings, our Pomello Bh and Paola Bw soil would be considered higher than the change points and the remaining three soils (Myakka Bh1, St. J ohns Bh, and St. Johns E) would be lower than the reported change points.

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83 When all five soils were used in correlation analysis, WSP was moderately to highly correlated to P M3 Al M3 PSR M3 DPS M3 OM, and SPSC M3 at the 9 and 27 week harvest ( r values not shown, all P values < 0.05). However, when soils were split into Bh (Myakka, Pomello, St. John) and non Bh (Paola and St. Johns) categories before correlation analysis, their respective r values all increased for soil parameters mention above. Initia lly, both the Pomello Bh and Paola Bw soils had negative SPSC M3 values, while the remaining three soils had positive SPSC M3 values (Table 3 1 ). At the 9 week harvest, the St. Johns Bh soil had significantly higher SPSC M3 values then all other soils, while the Pomello Bh and Paola Bw soils had the lowest SPSC M3 values of the soil s (Table 3 1 ). Similar trends in SPSC M3 values were determined for soils at the 27 week harvest date except for the Pomello Bh soil, which had significantly lower SPSC M3 values then the other four soils (Table 3 1 ). For the two non Bh soils harvested at 9 WAP, soil WSP was highly correlated to P M3 ( r = 0.95, P = 0.0003), PSR M3 ( r = 0.98, P < 0.0001), DPS M3 ( r = 0.98, P < 0.0001), and SPSC M3 ( r = 0.96, P = 0.0002). For the three Bh s oils harvested at 9 WAP, soil WSP was highly correlated to P M3 ( r = 0.94, P < 0.001), Fe M3 ( r = 0.94, P < 0.001), PSR M3 ( r =0.94, P < 0.0001), DPS M3 ( r =0.94, P < 0.0001), and SPSC M3 ( r = 0.96, P < 0.0001). Water soluble P concentrations of non Bh soils harvested at 27 WAP were highly correlated to the following soil parameters: P M3 ( r = 0.89, P = 0.003), PSR M3 ( r = 0.88, P = 0.004), DPS M3 ( r = 0.88, P = 0.004), and SPSC M3 ( r = 0.82, P = 0.003). Water soluble P concentrations of Bh soils harvested at 27 WAP were highly correlated to P M3

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84 ( r = 0.98, P < 0.0001), Fe M3 ( r = 0.88, P = 0.0004), PSR M3 ( r = 0.98, P < 0.0001), DPS M3 ( r = 0.98, P < 0.0001), and SPSC M3 ( r = 0.96, P < 0.0001). Leachate Drainage Depths Drainage collected from the soil columns significantly decreased with time over the 27 week study period for all soil s (Figure 3 1 ; P ). We reported a significant soil treatment effect on drainage depth at 4, 5, 9, 12, 13, 14, 15, 17, 23, 24, 25, and 26 WAP (Figures 3 2 and 3 3). At 4 WAP, significantly more water drained from the Myakka Bh1, Pomello Bh, and Paola Bw soil than compared to the two St. Johns soils (E and Bh ) ( Figure 3 2). By 5 WAP, significantly more water drained from the Myakka Bh1 soil than compared to the two St. Johns so ils (E and Bh) and the Paola Bw soil; no statistical differences were determined for drainage depths collected from the Myakka Bh1 and Pomello Bh soil (Figure 3 2). Significantly more water drained through the Myakka Bh1 soil than the other soils at 9 WAP (Figure 3 2). From 12 to 27 WAP, significantly more water generally drained from the St. Johns E than the other soils (Figures 3 2 and 3 3). However, at 12 WAP, significantly more water also drained from the Myakka Bh1 soil than compared to the Pomello Bh, St. Johns Bh and Paola Bw soils (Figure 3 2). At 13 WAP, significantly more water drained from the St. Johns E soil than compared to the Myakka Bh, Pomello Bh and Paola Bw soils; n o statistical differences were determined for drainage depths between the t wo St. Johns ( B h and E) soils (Figure 3 2). By 24 WAP, no statistical differences were determine for drainage depths between the two St. Johns soils (Bh and E), but significantly more water drained from the St. Johns E soil then compared to the re maining t hree soils (Myakk a Bh1, Pomello Bh, and Paola Bw) ( Figure 3 3). At 25 WAP, significantly more water drained from the St. Johns E soil than compared to the Pomello Bh and Paola Bw soils; no

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85 statistical differences were determined for drainage depths between the two St. Johns soils and the Myakka Bh1 soil (Figure 3 3). At 26 WAP, significantly more water drained from the St. Johns E soil than compared to the other four soils (Figure 3 3). Molybdate Reactive Phosphorus in Leachate Temporal trends in MRP concentrations show a significant spike in weekly leachate concentrations collected from the Paola Bw, St. Johns Bh, and St. Johns E soils for some weeks towards the end of the study; no statistical differences were determined between weekly MRP concentrat ions collected from the Myakka Bh1 and Pomello Bh soils throughout the 27 week study period (Figure 3 4). There was a significant soil treatment effect on MRP leachate concentrations collected at 2, 4, 9, 14, and 23 WAP (Figure 3 5). In general the Myakka Bh1 soil leached significantly higher MRP concentrations than most over soil s during the first 14 WAP (Figure 3 5). At 2 WAP, the Myakka Bh1 and Pomello Bh soil leached significantly higher MRP concentrations than the Paola Bw and the two St. Johns (Bh an d E) soils (Figure 3 5). At 4 WAP, the Myakka Bh 1 leached significantly higher MRP concentrations th a n the other four soil s ; the Pomello Bh soil leached significantly higher MRP concentrations than the Paola Bw and two St. Johns (E and Bh) soils (Figure 3 5). By 9 WAP, the Myakka Bh soil leached significantly higher MRP concentrations then all other soil s (Figure 3 5). At 14 WAP, the Myakka Bh1 soil leached significantly higher MRP concentrations than the St. Johns Bh and Paola Bw soils; no statistical differences were determined for MRP concentrations leached from the Pomello Bh and St. Johns E soil (Figure 3 5). By 23 WAP, The St. Johns E soil leached significantly higher MRP conc entr ations than the other four soil s (Figure 3 5).

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86 Temporal trends in MRP loads showed a significant decrease in P loads over the 27 week study period for l eachate collected from all soil s (Figure 3 6). There was a significant soil treatment effect on the MRP loads in leachate collected at 2, 4, 9, 14, 21, and 23 WAP (Figure 3 7). In general, the Myakka Bh1 soil leached significantly higher MRP loads then most all other soil treatments during the first 9 WAP (Figure 3 7) At 2 WAP, the Myakka Bh1 and Pomel lo Bh soil leached significantly higher MRP loads than the St. Johns Bh and Paola Bw soils, no statistical differences were determined for MRP loads collected from the St. Johns E soil (Figure 3 7). At 4 WAP, both the Myakka B h1 and Pomello soils leached s ignificantly higher MRP loads than the St. Johns Bh soil; no statistical differences were determined for the Paola Bw and St. Johns E soils (Figure 3 7). By 9 WAP, The Myakka Bh1 leached significantly higher MRP loads than the other four soils (Figure 3 7) At 14 WAP, the St. Johns E soil leached significantly higher MRP loads than the Paola Bw soil and at 21 WAP the St. Johns soil leached significantly higher MRP loads than the Myakka Bh1 and Paola Bw soils; no statistical differences were determined for remaining soil types (Figure 3 7). By 23 WAP, the St. Johns E soil was leaching significantly higher MRP loads then all other soil types except the St. Johns Bh soil (Figure 3 7). During the 9 week establishment period, cumulative MRP leachate loads colle cted from the Myakka Bh1 soil and Pomello Bh were significantly higher than cumulative MRP loads collected from the St. Johns E soils ; no statistical differences were determined between cumulative MRP leachate loads of the St. Johns Bh, Paola Bw, and St. Johns E soils (Figure 3 8). During the 27 week establishment period, cumulative MRP leachate loads collected from the Myakka Bh1 soil were not statistically different

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87 than cumulative MRP leachate loads collecte d from the Pomello Bh and St. Johns Bh soils, but were significantly higher than cumulative MRP leachate loads collected from the Paola Bw and St. Johns E soils which were not statistical d ifferent (Figure 3 8). There were moderate correlations between MRP concentrations and soil OM content ( r = 0.77, P = 0.003) and soil pH ( r = 0.69, P = 0.01) at 9 WAP for the three Bh (Myakka, Pomello, St. Johns) horizons soils. No significant ( P > 0.05 ) correlations were determined between MRP concentrations and soil pr operties at the 9 and 27 week harvest for the two non Bh soils (Paola and St. Johns) and for the three Bh soils at the 27 week harvest. Turfgrass root biomass was moderately correlated ( r = 0.47, P = 0.04) to MRP concentrations at 9 WAP. Dissolved Reacti ve Orthophosphate Filtered in Leachate Temporal trends in DRP concentrations show a significant spike in weekly leachate concentrations collected from the Paola Bw, and St. Johns Bh soils for some weeks towards the end of the study; no statistical differences were determined between weekly DRP concentrations collect ed from the Myakka Bh1, Pomello Bh and St. Johns E soils throughout the 27 week study period (Figure 3 9 ) We observed a significant soil treatment effect on DRP leachate concentrations (Figure 3 10) and loads (Figure 3 11) at 2, 3, 4, 5, 6, and 9 WAP. In general the Myakka Bh1 soil leached significantly higher DRP concentrations (Figure 3 10) and loads (Figure 3 1 1 ) then leachate collected from most other soil s during the first 9 WAP. At 2 WAP, the Myakka Bh1 and Pomello Bh soil leached significantly higher DRP concentrations and loads than the St. Johns Bh and Paola Bw soils; no statistical differences were determined fo r DRP concentrations and loads collected from the St. Johns E soil (Figure 3 10 and 3 11). At 3 WAP, both the Myakka Bh1 and Pomello Bh soils leached significantly higher DRP concentrations and

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88 loads than the Paola Bw soil; no statistical differences were determined for DRP concentrations and loads collected from the two St. Johns (Bh and E) soils (Figures 3 10 and 3 11). At 4 and 5 WAP, the Myakka Bh1 leached significantly higher DRP concentrations and loads than the other four soil s; the Pomello Bh1 soil leached significantly higher DRP concentrations than both St. J ohns (Bh and E) and the Paola Bw soil s At 4 and 5 WAP, the Pomello Bh1 soil leached significantly higher DRP loads than both the St. Johns Bh and the Paola Bw soils whi le the St. Johns E soil had statistically similar DRP loads (Figures 3 10 and 3 11). By 6 WAP, the three Bh soils (Myakka, Pomello, and St. Johns) leached significantly higher DRP concentrations than the Paola Bw soil; no statistical differences were deter mined for the St. Johns E soil (Figure 3 10). The St. Johns Bh soil leached significantly higher DRP loads than the Paola Bw and St. Johns E soils while no statistical differences were determined for DRP loads collected from the Myakka Bh1 and Pomello Bh s oil s at 6 WAP (Figure 3 11). At 9 WAP, The Myakka Bh1 soil leached significantly higher DRP concentrations and loads than the other four soil s (Figure 3 10 and 3 11). Temporal trends in DRP loads showed a significant decrease in leached P over the 27 week study period for all soil s (Figure 3 12). No significant correlation relationships between DRP concentrations and soil properties where determined for non Bh soil s at 9 and 27 WAP and for Bh soil s at 27 WAP. Cumulative DRP loads leached from the Myakka Bh1 soil were statistical similar to the loads collected from the Pomello Bh soil and significantly higher cumulative DRP loads than the St. Johns Bh, Paola Bw and St. Johns E soil s during the 9 week establishment study ; cumu lative DRP loads leached from the Paola Bw soil were

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89 sig nificantly lower than all soil s except for the St. Johns E soil which were statistical similar (Figure 3 13). During the 27 week study, the Myakka Bh soil had significantly higher cumulative DRP loads than the other four soils ; cumulative DRP loads leached from the Pomello Bh soil were significantly higher than the Paola Bw soil and statistical similar to the two St. Johns (Bh and E) soils (Figure 3 13). High correlations were determined between DRP c oncentrations and the following soil parameters: pH ( r = 0.75, P = 0.005 and OM ( r = 0.77, P = 0.003) for the three Bh (Myakka, Pomello, and St. Johns E) soils collected at 9 WAP. Turfgrass root biomass was moderately correlated ( r = 0.45, P = 0.04) to DRP concentrations at 9 WAP. Total Dissolved Phosphorus Filtered in Leachate There was a significant soil treatment effect on TDP leachate concentrations (Figure 3 14) and loads (Figure 3 15) collected at 1, 2, 3, and 4 WAP. Leachate TDP concentrations and loads were significantly higher from the Myakka Bh1 soil than the other soils for the first 4 WAP. For the first WAP, The Pomello Bh soil leached significantly higher TDP leachate concentrations and loads than the St. Johns E soil and s tatistically similar TDP leachate concentrations and loads to the St. Johns Bh and Paola Bw soils (Figures 3 14 and 3 15). At 2, 3, and 4 WAP; The Pomello Bh soil leach significantly higher TDP leachate concentrations and loads than Paola Bw soil and stati stically similar TDP leachate concentrations and loads to the two St. Johns (E and Bh) soils the for the first 4 WAP (Figure s 3 14 and 3 15). High correlations between TDP leachate concentrations and the following 9 week harvest soil parameters: pH ( r = 0 .67, P = 0.001) and OM ( r = 0.77, P < 0.0001) were determined for leachate collected at 4 WAP.

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90 Turfgrass Root Biomass A significant soil treatment effect was determined for root dry biomass at the 9 and 27 week harvest ( P Table 3 2 ). No statistic al differences were determined for root biomass of STA grown on St. Johns Bh, Paola Bw, and St. Johns E soil; however, STA grown on the St. Johns Bh soil produced significantly higher root biomass than STA grown on the Myakka Bh1 and Pomello Bh soils durin g the 9 week establishment period (Table 3 2 ). St. a ugustinegrass grown on St. Johns E soil produced significantly lower root biomass then STA grown on the other four soils during the 27 week establishment period (Table 3 2 ). Discussion Soil P M3 Fe M3 and Al M3 concentrations where all within the reported ranges of M3 nutrient concentrations of acidic soils from Delaware used in a P leaching study by Maguire and Sims (2002) and a P storage capacity study of Florida acidic soils by Chakraborty et al. (2011b) However, some of s oil M3 concentrations reported by Chakraborty et al. (2011b) and Maguire and Sims (2002) had higher maximum P M3 and Fe M3 concentrations than determined for our study The Bh soils used in our study generally had higher OM contents and lower pH values than soils used by Maguir e and Sims (2002) but comparable p H values to most Bh soils reported by Chakraborty et al. (2011b) T he two non Bh soils used in our study had comparable pH values and soil OM contents to most of the soils used in the leaching study by Maguire and Sims (2002) and comparable pH values to A and E horizons reported by Chakraborty et al. (2011b) The high OM contents determined for Bh samples in our study suggests that other mass losses (e.g., dehydroxylation) may be contributing to the LOI values

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91 The soil WSP concentrations of soils used in our s tudy were comparable to some of the WSP concentrations of A, E, and Bh horizons reported by Chakraborty et al. (2011b) however the author s reported some soil horizons with higher WSP concentrations than determined for soils used in our study Soil bulk density values in the PVC columns were all below the reported root penetration threshold value of 1.75 g cm 3 for sand y soils ( Brady and Weil 2002) and t urfgrass root lengths for all soil treatments were at the bo ttom of the so il columns by the end of 27 week harvest. Usually for acid soils, higher PSR M3 and DPS M3 values correspond to higher soil WSP concentrations ( Nair et al., 2004) or higher DRP concentrations in leachate ( Maguire and Sims, 2002; Sims et al., 2002) When the soils in our study were separated into non Bh and Bh horizon categories we observed high correlations between PSR M3 and DPS M3 values to soil WSP concentrations for most of our soils ex cept the Myakka Bh1 soil. T he Paola Bw, which had the highest DPS M3 value (31.0%), had similar WSP (0.89 m g kg 1 ) concentrations to the WSP of the Myakka Bh1 (0.84 m g kg 1 ) soil, which had a lower DPS M3 value of 0.87% at 9 WAP. The Myakka Bh1 and St. Johns Bh soils had similar WSP concentrations to the Paola Bw soil despite having significantly lower soil DPS M3 values at 27 WAP. The PSR M3 values of all soils used in our study w ere below the change point of 0.23, above which Maguire and Sims (2002) reported a rapid increase in dissolved leachate P concentrations for acidic sandy soils from Delaware Chakraborty et al. (2011b) proposed a lower PSR M3 change point of 0.09 for Florida Bh horizons, which was similar to the PSR M3 c hange point of 0.08 for sandy surface horizon soils reported by Nair et al. (2004) No significant

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92 relationships between leachate P (MRP, DRP, and TDP ) concentrations and DPS M3 and PSR M3 values were determined for soil used in our study. Chrysostome et al. (2007) reported that soils act as a P sink when SPSC is positive, and as a potential P source when SPSC is negative. In our study, the Myakka Bh1 soil had positive SPSC values indicating that the soil has the capacity to adsorb more P before reaching DPS M3 and PSR M3 change points ; however, we observed significantly higher leachate P ( MRP, DRP, and TDP ) concentrations and loads from t he Myakka Bh soils then soils with higher WSP and negative SPSC values throughout the 27 week study. The comparable WSP concentrations of the Myakka Bh1 and the Paola Bw soil and the higher leachate P collected from the Myakka Bh1 may be attributed to the presence in and release of organically complexed P from the Myakka Bh1 soi l. Wright and Reddy (2012) reported that water containing dissolved OM is darkly colored and can carry carbon (C), N, P, and metals with it. Dissolved OM and associated or complexed ions can readily move through the soil (Kaschl et al., 200 2; Qualls and Haines 1992) The dark color of the drainage water collected from the Myakka Bh1 soil support the hypothesis of this soil leaching P complexed with DOM. The significant correlation between WSP and leachate concentrations to soil OM reported in our study may also support this idea that some complexed P was being leached with DOM. This hypothesis of complexed P leaching with DOM may explain why we observed h igher or no statistical differences in cumulative DRP and MRP of the lower DPS M3 and PSR M3 Bh horizon (Myakka, Pomello, and St. Johns) soils compared to the Paola Bw soil (which had significantly higher DPS M3 and PSR M3 values).

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93 The significant decrease in drainage depths from the beginning to the end of the study can be attributed to the reduction of irrigation volumes, because irrigation was the only source of water applied to the columns. High drainage volumes during the first 9 WAP were also likely a res ult of the short time frame of the study, which did not allow enough time for roots to fully develop. Specifically, the higher drainage volume collected from the St. Johns E soil starting at 12 WAP may be attributed to the significantly lower root mass col lected from turfgrass grown on the St. Johns E soils when compared with turf grass grown on the other soil treatments at the 27 week harvest date. Scherer Lorenzen et al. (2003) showed a negative relationship between root biomass and leaching volumes from grasslands, indicating that roots play an important role in intercepting water and nutrients and reducing leaching Our study reported a moderate ly negative correlation relationship between turfgrass root biomass and leachate P ( MRP and DRP ) concentrations at 9 WAP. The low soil OM content of the St. Johns E soil and the possible formation of preferential flow channels are two additional properties t hat may have contributed to the higher drainage volumes reported for the St. Johns E soil. The significant decrease in DRP MRP and TDP loads observed over the 27 week study period may also be attributed to the reduction of irrigation as the study progressed The high irrigation inputs required for turfgrass establishment increase the potential for nutrients to be moved below the root zone and lost to leaching ( Barton and Colmer, 2006; Erickson et al., 2005; King et al., 2006; Synder et al., 1984) For example, Erickson et al. (2005) reported that P leaching losses were severely higher earlier on in the study period than when compared to later months The significant in crease of MRP and DRP concentrations leached from some soils during the last few

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94 weeks of our study (when compared to earlier concentrations) were likely a result of the decrease in leachate volumes over the study period. Re sults from our study show that MRP and DRP concentrations ranged from 0 to 0.5 mg L 1 and 0 to 0.3 mg L 1 respectively, for all soil treatments during the 27 week study period. Lawson and Colclough (1991) and Petrovic (2004) reported similar P leachate concentrations on MRP (0 to 0.3 mg L 1 ) and DRP (maximum = 0.19 mg L 1 ) from fertilized sandy soils. However, Engelsjord and Singh (1997) reported DRP concentrations ranging from 0.11 to 10.25 mg L 1 Average across all soil treatments MRP and DRP 9 week cumulative loads were 0.24 and 0.1 9 kg ha 1 respectively for our study When a verage d across all soil treatments 27 week cumulative MRP and DRP loads were 0.28 and 0.21 kg ha 1 respectively, which were similar to our 27 week loads ; these results were expected since P fertilizer was only added at 30 DAP Erickson et al. (2010) reported similar cumulative 2 month P loads of 0.27 kg ha 1 0.13 kg ha 1 for some of their STA treatments establishing on sandy soils Erickson et al. (2005) reported significantly highe r cumulative 2 month P loads of 2.5 kg ha 1 during the STA 2 month establishment period. However, most of these referenced studies applied P fertilizer at higher rates and fre quencies then we did in our study so it is expected that we would report lower P concentrations and loads. Results from our study did indicate that even with low P additions fill materials can leach P loads that may still have environmental implications. Higher fertilizer and irrigation regimes than used in our study may further increase the potential for P leaching during turfgrass establishment periods. Phosphorus saturation ratio, DPS, and SPSC have all been considered important tools for evaluating t h e P saturation status of soils. These P saturation measurements

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95 were shown to be effective in identifying acidic soils that may pose possible environmental risk for P losses in our study when they were separated into non Bh and Bh categories However, our results did show that some acid ic sandy soils with low P saturation status (low PSR M3 and DPS M3 values) and high re maining P sorption capacity (positive SPSC M3 values) still act ed as a potential source s of P even when little P was added to them. Our study evaluated only a few types of soils and we found one main deviation from published study results, while other studies evaluating much larger soil sets showed positive relationships between high PSR or DPS change points and increas e leachate P concentrations or soil WSP concentrations. However, our results suggest that established PSR and DPS change points along with SPSC calculations may not be able to accurately predict the leaching potential of all soils when they are removed fro m their natural settings and applied as fill materials

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96 Table 3 1. Mean selected chemical properties of Florida soil fill materials used in a column study to evaluate the effect of soil properties on phosphorus leaching from st. augustinegrass at 0, 9, and 27 weeks after planting Harvest date and soil m aterial O rganic matter (gkg 1 ) pH Mehlich 3 Ca (mgkg 1 ) Mehlich 3 Fe (mgkg 1 ) Mehlich 3 Al (mgkg 1 ) Mehlich 3 P (mgkg 1 ) Water soluble P ( m g kg 1 ) PSR z DPS y (%) SPSC x ( m g kg 1 ) 0 weeks after planting Myakka Bh1 67.5 4.1 333 27.6 988 <12.5 0.45 0.004 0.69 99.2 Pomello Bh 60.6 4.3 14.2 <5.0 w 1593 193 1.25 0.105 19.12 27.8 St. Johns Bh 41.6 4.1 14.1 37.3 1481 <12.5 0 0.006 1.04 145.2 Paola Bw 3.8 5.3 24.2 60.9 643 123 0.03 0.159 28.97 53.6 St. Johns E 1.6 5.8 29.3 <5.0 145 <12.5 0 0.026 4.73 10.8 9 weeks after planting Myakka Bh1 67.6 a v 4.1 c 356 a 36.6 c 1138 c <12.5 c 0.84 bc 0.004 d 0.87 d 113.3 b Pomello Bh 61.2 a 4.5 b 42.4 b < 5.00 e 2406 a 339 a 2.80 a 0.123 b 22.3 b 90.3 d St. Johns Bh 39.1 b 4.5 b 71.0 b 68.6 b 1962 b <12.5 c 0.13 d 0.003 e 0.50 e 200.1 a Paola Bw 3.00 c 6.9 a 51.2 b 148 a 737 d 158 b 0.89 b 0.171 a 31.0 a 74.7 d St. Johns E 2.20 d 6.8 a 62.2 b 5.10 d 171 e <12.5 c 0.26 cd 0.031 c 5.72 c 11.7 c 27 weeks after planting Myakka Bh1 66.1 a 4.0 b 330 a 32.7 c 1121 c <12.5 d 0.24 bc 0.005 e 0.87 e 111.3 b Pomello Bh 69.0 a 4.5 b 65.7 b <5.00 d 2172 a 313 a 2.50 a 0.126 b 22.8 b 88.1 e St. Johns Bh 37.8 b 4.4 b 94.1 b 58.8 b 1862 b 18.1 c 0.16 bc 0.009 d 1.51 d 177.4 a Paola Bw 3.00 c 6.8 a 89.7 b 73.6 a 591 d 125 b 0.59 b 0.174 a 31.6 a 60.2 d St. Johns E 2.30 c 6.6 a 87.1 b <5.00 d 155 e <12.5 d 0.14 c 0.036 c 6.37 c 10.0 c z Phosphorus saturation ratio. y Degree of phosphorus saturation. x Soil phosphorus saturation capacity. w Less then the detection limit of inductively couple d plasma atomic emission spectroscopy v Mean ant difference test at P

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97 Table 3 2. Mean biomass of roots of st. augustinegrass grown on different Florida soil fill materials in a soil column conducted in Wimauma, FL. Harvest date Root and biomass soil material (g) 9 week harvest Myakka Bh1 2.29 b Pomello Bh 2.65 b St. Johns Bh 4.92 a Paola Bw 3.32 ab St. Johns E 2.90 ab 27 week harvest Myakka Bh1 8.58 a Pomello Bh 7.72 a St. Johns Bh 7.13 a Paola Bw 8.50 a St. Johns E 3.25 b z P 0.05.

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98 Figure 3 1. Temporal trends in mean weekly drainage collected soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials. Irrigation depths are shown on the top graph with the drainage to irriga tion ratios shown in the middle graph. Irrigation depths for week six are missing due to a power outage to automatic timer that resulted in an unknown amount of water applied.

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99 Figure 3 2. Mean drainage depths of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials at 4, 5, 9, 12, 13, and 14 weeks after planting (WAP). Values within the same collection date with the same letter are not significantly different at P < 0

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100 Figure 3 3. Mean drainage depths of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials at 15, 17, 23, 24, 25, a nd 26 weeks after planting (WAP). Values within the same collection date with the same letter are not significantly different at P

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101 Figure 3 4. Temporal trends in mean weekly molybdate reactive phosphorus concentrations in leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials.

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102 Figure 3 5. Mean molybdate reactive phosphorus concentrations of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials at 2, 4, 9, 14, and 23 weeks after planting (WAP). Values within the same collection dat e with the same letter are not significantly different at P difference test.

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103 Figure 3 6. Temporal trends in mean molybdate reactive phosphorus loads in leachate collected from soil columns evaluating phosphorus l eaching from st. augustinegrass establishing on different soil fill materials.

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104 Figure 3 7. Mean molybdate reactive phosphorus loads of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials at 2, 4, 9, 14, 21, and 23 weeks after planting Values within the same collection date with the same letter are not significantly different at P test.

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105 Fi gure 3 8. Mean cumulative molybdate reactive phosphorus loads in leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials during the 9 and 27 week establishment periods. Valu es within the same collection period with the same letter are not significantly different at P significant difference test.

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106 Figure 3 9. Temporal trends in mean weekly dissolved reactive orthophosphate concentrations in leach ate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials.

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107 Figure 3 10. Mean dissolved reactive orthophosphate concentrations of leachate collected from soil columns evaluating p hosphorus leaching from st. augustinegrass establishing on different soil fill materials at 2, 3, 4, 5, 6, and 9 weeks after planting (WAP). Values within the same collection date with the same letter are not significantly different at P < 0.05 using Tukey significant difference test.

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108 Figure 3 11. Mean dissolved reactive orthophosphate loads of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials at 2, 3, 4, 5, 6, and 9 weeks after planting. Values within the same collection date with the same letter are not significantly different at P test.

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109 Figur e 3 12. Temporal trends in mean dissolved reactive orthophosphate loads of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials.

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110 Figure 3 13. Mean cumulative dissolved reactive orthophosphate loads in leachate collected from soil coulmns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials during the 9 and 27 week establishment periods. Values within the same col lection period with the same letter are not significantly different at P honestly significant difference test.

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111 Figure 3 14. Mean total dissolved phosphorus concentrations of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials during the first four weeks after planting. Values within the same collection period with the same letter are not significantly different at P < 0.05 using test.

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112 Figure 3 15. Mean total dissolved phosphorus loads of leachate collected from soil columns evaluating phosphorus leaching from st. augustinegrass establishing on different soil fill materials during the fir st four weeks after planting. Values within the same collection period with the same letter are not significantly different at P

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113 CHAPTER 4 CONCLUSION Urban soil s are typically disturbed due to cutting, mixing, and filling activities that occur during land development. Imported fill soil materials that are transported from various locations often contain variable amounts of sorbed phosphorus (P) and variable chemi cal properties that can affect their capacity to retain additional P. Over the 27 week study period, the low pH and high levels of organically complexed Al and Fe in spodic (Bh) horizons did not affect P bioavailability to and establishment of quality st. augustinegrass (STA) when used as topsoil fills. Results from this study did not dismiss the use of Bh horizons as fill materials in urban settings. However, homeowners should be aware that the potential for nutrient deficiencies to occur and production of low quality turfgrass may be elevated when growing on Bh horizon. Standard soils test (Mehlich 1 or Mehlich 3) or P saturation measurements like the P saturation ratio (PSR) ential for establishing turfgrass as other physical and chemical properties are likely factors in turfgrass establishment. The use of P saturation equations like the PSR, DPS, and SPSC were generally able to accurately predict P leaching loss from f ill materials throughout our 27 week study. However, results from this study show that soil fill materials (mainly Bh) with low calculated P leaching loss potentials (low PSR and DPS values; positive SPSC values) can still leach high P concentrations and loads and can have comparable water soluble P concentrations to fill materials with higher calculated PSR and DPS values. This finding is important for environmental risk protection since soils with low predicted P loss potentials and little P added to them sti ll can leached P concentrations that may

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114 impacted the quality surrounding water bodies. Results from our study also indicated that fill materials collected from different soil horizons should have different P saturation change points or threshold values. While the results of this study did not indicate that use of a Bh horizon derived soil material will affect the establishment of STA, quality effects on STA grown on Bh horizons may be observed in STA if grown on Bh fill materials for longer periods th en conducted in this study Future field plot studies need to be performed to evaluate the long term effects on the quality of STA when using Bh horizons as fill materials. Future research should also evaluate the P leaching potential of many different soi l fill materials with a wide range of initial P concentrations. Also more research needs to be conducted to confirm if other Bh and non Bh horizon fill materials with low PSR and DPS values and positive SPSC values can act as possible P sources.

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115 APPENDIX CHEMICAL PROPERTIES AND PHOSPHORUS SORPT ION CAPACITY OF SELECTED FLORIDA SPO DIC HORIZONS Soil Sample Collection Soil samples from 30 spodic ( Bh ) horizons were obtained from five different geographical locations throughout Florida. Twelve Bh horizon samples were collected from various locations in the Austin Cary Memorial Forest (ACMF), located just northeast of Gainesville, FL (Site 1 Figure 2 1). Four of the twelve soil samples in ACMF were collected by auger from the Bh horizon of a Newnan sand (Sandy, s iliceous, hyperthermic Oxyaquic Alorthod) ( Soil Survey Staff 2010) Eight of the twelve samples were collected from a Pomona sand (Sandy, siliceous, hyperhtermic Ultic Alaquod) ( Soil Survey Staff 2010) Two of the eight Pomona sand samples were c ollected from auger from different locations within ACMF. The remaining six of the eight Pomona sand samples were collected by shovel from a soil pit. Samples were taken from different depths and locations within the Bh horizon exposed in the soil pit. Fo ur Bh horizon samples were collected from two soil pits at the University of Florida Institute of Food and Agricultural Sciences Gulf Coast Research and Education Center (GCREC) located in Wimauma, FL (Site 2 Figure 2 1). Two of the four soil samples we re collected by shovel from a Bh horizon of a Myakka sand (Sandy, siliceous, hyperthermic Aeric Alaquod) (Soil Survey Staff 2010) The remaining two soil samples were collected by shovel from a Bh horizon of a Zolfo sand (Sandy, siliceous, hyperhtermi c Oxyaquic Alorthods) (Soil Survey Staff 2010) An additional 11 samples were collected by auger from a commercial tomato farm located in Duette, FL (Site 3 Figure 2 1). Four of the 11 samples were collected from different Bh horizons of a Cassia san d (Sandy, siliceous, hyperthermic Oxyaquic Alorthods) ( Soil Survey Staff

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116 2010) The remaining seven of the 11 samples were collected from different locations within the farm from the Bh horizons of a Myakka sand (Sandy, siliceous, hyperthermic Aeric A laquod) ( Soil Survey Staff 2010) The next soil sample was collected near Labelle, FL at a private cattle farm dominated by pine flatwoods vegetation (Site 5 Figure 2 1). A small circular soil pit was hand dug using a shovel. Soil was excavated from the Bh1 horizon of a Myakka sand (Sandy, siliceous, hyperthermic Aeric Alaquods) ( Soil Survey Staff 2010) An additional soil sample was collected from an active borrow pit operation located just southeast of Jacksonville, FL (Site 4 Figure 2 1). So il was removed from the ground by backhoe operations prior to our arrival. The soil was collected from a Bh horizon of a Pomello fine sand (Sandy, siliceous, hyperthermic Oxyaquic) ( Soil Survey Staff 2010) Soil was also collected from a new residenti al housing development located east of Fruit Cove, FL (Site 4 Figure 2 1). Various soil horizons were exposed in a circular trench that was excavated prior to sampling. The exposed Bh horizon of a St. Johns sand (Sandy, siliceous, hyperthermic Typic Alaqu ods) ( Soil Survey Staff 2010) was collected. Soil Characterization Soil samples were air dried at 25 2C for 12 to 14 days and sieved to pass a 2 mm screen. Soil pH (1:2 soil to deionized water ratio), electrical conductivity (EC 1:2 soil to deion ized water ratio), and organic matter (OM loss on ignition) were determined using standard methods ( Mylavarapu 2009) Soil samples were extracted using the M ehlich 3 (M3) metho d (1:7 ratio of soil to 0.2 M CH 3 COOH + 0.25 M NH 4 NO 3 + 0.015 M NH 4 F + 0.013 M HNO 3 + 0.001 M EDTA) ( Baker et al., 2002) Mehlich 3 extracts were analyzed for p hosphorus (P), c alcium (Ca), a luminum (Al), and i ron (Fe) using inductively couple d plasma atomic emission spectroscopy ( ICP AES ) at the Analytical

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117 Research Laboratory (ARL) in Gainesville, FL. The M3 PSR (PSR M3 ) values for the soils were calculated using the following equation: PSR M3 = P M3 / (Al M3 + Fe M3 ) where P M3 Al M3 and Fe M3 are the concentration of M3 P, Al, and Fe expressed in mmol kg 1 (Maguire and Sims, 2002) Degree of P saturation was calculated using the following equation: DPS M3 = [(P M3 ) / (Al M3 + Fe M3 )] x 100, w here P M3 Al M3 and Fe M3 the concentration of M3 P, Al, and Fe are expressed in mmol kg 1 and is an empirical factor that compares different soils with respect to P saturation ( Nair and Graetz 2002) Water soluble P (WSP) was determined by extracting soil with deionized water at a 1:10 soil to wate r ratio for 1 h, and determining P on the filtrate collected after passing through a 0.45 m filter (Self Davis et al., 2009) Phosphorus sorption index (PSI) was determined by adding 20 mL of 0.0012 M P sorption solution to 1 g of soil and shaking for 18 h. After shaking, the solution was placed in a centrifuge at 2000 rpm for 30 mins. The centrifu gate was filtered through a 0.45 um filter ( Sims 2009a) Phosphorus sorption index (PSI) was calculated using the following equation ( Sims 2009a) : PSI ( kg 1 ) = X / log C, where: kg 1 ) = [(75 mg P / L P f ) x (0.020 L)] / (0.001 kg soil) 1 ), and P f 1 ).

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118 Phosphorus concentration in the filtered supernatants from the WSP and PSI tests were determined on a spectrophotometer (Genesys 20; Thermo Fisher Scientific) at 880 nm using the molybdate blue method ( Murphy and Riley 1962) Soils were digested using the EPA method 3050 hot acid digestions (U.S. Environmental Protection Agency 1986) and analyzed for total P using ICP AES at the ARL in Gainesville, FL.

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119 Table A 1. Selected chemi cal properties and phosphorus measurements of 30 Bh horizon samples collected from five locations throughout Florida. Soil series /location and number pH Organic matter ( gkg 1 ) Electrical conductivity cm 1 ) P sorption index kg 1 ) Water soluble P 1 ) Total P kg 1 ) Newnan /ACMF z 1 4.8 44.7 74.5 311 0.18 61.5 Newnan /ACMF 2 4.8 37.8 67.2 211 0.51 74.4 Newnan /ACMF 3 5.1 24 65.5 135 0.25 39 Newnan /ACMF 4 4.7 25.2 67.8 210 0.03 58 Pomona /ACMF 5 5.7 7.1 47.6 81.3 0.4 38.8 Pomona /ACMF 6 5.5 21.1 79.1 183 0.47 65.5 Pomona /ACMF 7 5.1 30.5 57.1 157 3.5 154 Pomona /ACMF 8 5.4 18.6 43.3 144 5.8 172 Pomona /ACMF 9 5.3 24.5 54.3 233 3.2 149 Pomona /ACMF 10 5.2 22.2 53.4 185 3.8 156 Pomona /ACMF 11 5.5 14.4 41.9 110 5.8 160 Pomona /ACMF 12 5.6 17.5 44.2 130 6.7 180 Myakka /GCREC y 13 5.5 11.7 54.1 172 0.09 183 Myakka /GCREC 14 5.3 10.8 49 154 0.08 163 Zolfo /GCREC 15 5.3 17.1 76.8 256 0.11 613 Zolfo /GCREC 16 5.2 19.9 83.2 304 0.06 666 Cassia /Duette 17 6.7 30.7 77.9 257 9.8 1299 Cassia /Duette 18 5.5 31.3 74.8 216 6.6 676 Cassia /Duette 19 5.5 38.8 130 275 2.1 327 Cassia /Duette 20 5.3 40.9 105 572 0.04 1237 Myakka /Duette 21 5.9 10.5 63 143 0.29 88.4 Myakka /Duette 22 6.5 11.5 65.6 128 1.7 122 Myakka /Duette 23 5.4 30.6 274 327 0.03 108 Myakka /Duette 24 6.2 16 63 194 0.17 74.1 Myakka /Duette 25 6.8 12 57.6 203 0.19 204

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120 Table A 1. Continued. Soil series /location and number pH Organic matter ( gkg 1 ) Electrical conductivity cm 1 ) P sorption index kg 1 ) Water soluble P 1 ) Total P kg 1 ) Myakka /Duette 26 6.4 64.1 30.2 754 0.5 990 Myakka /Duette 27 5.9 26.7 148 347 0.18 114 Myakka /Labelle 28 4.1 67.5 0.45 Myakka /Fruit Cove 29 4.3 60.6 1.3 St. Johns /Jacksonville 30 4.1 41.6 0 Mean 5.4 27.7 75.8 237 1.8 303 Standard Deviation 0.7 16 47.2 143 2.6 364 Maximum 6.8 67.5 274 754 9.8 1299 Minimum 4.1 7.1 30.2 81.3 0 38.8 Range 2.7 60.4 243 673 9.8 1260 z Austin Cary Memorial Forest. y Gulf Coast Research and Education Center. Table A 2. Mehlich 3 nutrients and phosphorus saturation measurements of 30 Bh horizon samples collected from five locations throughout Florida. Soil series/location and number Mehlich 3 P (mgkg 1 ) Mehlich 3 Ca (mgkg 1 ) Mehlich 3 Fe (mgkg 1 ) Mehlich 3 Al (mgkg 1 ) PSR DPS (%) Newnan/ACMF 1 < 12.5 41.1 36.4 2002 0.003 0.49 Newnan/ACMF 2 30.5 12.4 16 1398 0.019 3.43 Newnan/ACMF 3 18.6 19.1 50.8 1105 0.014 2.61 Newnan/ACMF 4 30.5 12.6 12.27 1354 0.02 3.55 Pomona/ACMF 5 24.8 8.7 7.85 555 0.039 7.04 Pomona/ACMF 6 41.3 11.1 43.2 1035 0.034 6.2 Pomona/ACMF 7 133 16.6 44 1174 0.097 17.63

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121 Table A 2 Continued. Soil series/location and number Mehlich 3 P (mgkg 1 ) Mehlich 3 Ca (mgkg 1 ) Mehlich 3 Fe (mgkg 1 ) Mehlich 3 Al (mgkg 1 ) PSR z DPS y (%) Pomona/ACMF x 8 166 19.9 32.8 1087 0.131 23.79 Pomona/ACMF 9 115 9.4 30.2 1425 0.07 12.64 Pomona/ACMF 10 140 7.7 23.2 1366 0.089 16.12 Pomona/ACMF 11 173 9.8 28.4 1112 0.134 24.35 Pomona/ACMF 12 198 6.9 40.9 1273 0.134 24.29 Myakka/GCREC w 13 74.6 41.7 48 1128 0.056 10.26 Myakka/GCREC 14 68.8 30.2 47.9 1129 0.052 9.46 Zolfo/GCREC 15 63.1 27.4 17.6 1368 0.04 7.26 Zolfo/GCREC 16 57.1 33.3 19.7 1457 0.034 6.17 Cassia/Duette 17 388 1534 13.8 1332 0.253 45.94 Cassia/Duette 18 379 131 7.9 1491 0.221 40.19 Cassia/Duette 19 135 466 54.8 1385 0.083 15.14 Cassia/Duette 20 57.5 12.4 6.8 1585 0.032 5.74 Myakka/Duette 21 25.4 252 174 718 0.028 5.02 Myakka/Duette 22 68.9 574 28.3 736 0.08 14.54 Myakka/Duette 23 < 12.5 233 5.6 1505 0.004 0.66 Myakka/Duette 24 25.5 330 33.5 1136 0.019 3.51 Myakka/Duette 25 57.3 348 11.3 1183 0.042 7.64 Myakka/Duette 26 15.6 349 < 5.0 1687 0.008 1.47 Myakka/Duette 27 15.2 203 37.5 1467 0.009 1.62 Myakka/Labelle 28 < 12.5 333 27.6 988 0.004 0.69 Myakka/Fruit Cove 29 193 14.2 < 5.0 1593 0.105 19.12 St. Johns/Jacksonville 30 < 12.5 14.1 37.3 1481 0.006 1.04 Mean 90.7 170 31.4 1275 0.062 11.25 Standard Deviation 99.2 304 31.1 300 0.063 11.38

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122 Table A 2 Continued. Soil series/location and number Mehlich 3 P (mgkg 1 ) Mehlich 3 Ca (mgkg 1 ) Mehlich 3 Fe (mgkg 1 ) Mehlich 3 Al (mgkg 1 ) PSR z DPS y (%) Maximum 388 1534 174 2002 0.253 45.94 Minimum 12.5 6.9 5 554.8 0.003 0.49 Range 376 1527 169 1447 0.25 45.45 z Phosphorus saturation ratio. y Degree of phosphorus saturation. z Austin Cary Memorial Forest. y Gulf Coast Research and Education Center.

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123 Figure A 1. Geographic locations of 30 Bh horizon samples collected for the characterization of various chemical properties. Site 4 Site 5 Site 3 Site 1 Site 2

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124 LIST OF REFERENCES Anderson, D.M., P.M. Glibert, and J.M. Burkholder. 2002. Harmful algal blooms and eutrophication: nutrient sources, composition, an d consequences. Estuaries 25:704 726. Baker, W.H., C.G. Herron, S.D. Carroll, M.A. Henslee, D.C. Lafex, and E.E. Evans. 2002. A comparative summary of standard Mehlich 3 soil test with a modified Mehlich 3 dilution ratio procedure. Arkansas Agricultural Ex pt. Sta., Univ. Arkansas, Fayetteville. < http://arkansasagnews.uark.edu/205.pdf >. Ballard, R. and J.G.A. Fiskell. 1974. Phosphorus retention in coastal plain forest soils: Relationship to soil properti es. Soil Sci. Soc. Amer. J. 38:250 255. Barton, L. and T.D. Colmer. 2006. Irrigation and fertiliser strategies for minimising nitrogen leaching from turfgrass. Agric. Water Mgt. 80:160 175. Beard, J.B. and R.L. Green. 1994. The role of turfgrasses in envir onmental protection and their benefits to humans. J. Environ. Qual. 23:452 460. Borggaard, O.K., S.S. Jorgensen, J.P. Moberg, and B. Rabenlange. 1990. Influence of organic matter on phosphate adsorption by aluminum and iron oxides in sandy soils. J. Soil S ci. 41:443 449. Bouyoucos, G.J. 1962. Hydrometer method improved for making particle size analyses of soils. Agron. J. 54:464 465. Brady, N.C. and R.R. Weil. 2002. The nature and properties of soil. 13th ed. Prentice Hall, Upper Saddle River, NJ. Brar, G. S. and A.J. Palazzo. 1995. Shoot and root development of tall and hard fescues in 2 different soils. J. Environ. Qual. 24:777 781. Breeuwsa, A., J.G.A. Rijerink, and O.F. Schoumans. 1995. Impact of manure on accumulation and leaching of phosphate in areas of intensive livestock farming, p. 239 249. In: K. Steele (ed.). Animal watse and the land water interface. Lewis CRC Press, N.Y. Broschat, T.K. and M.L. Elliott. 2004. Nutrient distribution and sampling for leaf analysis in St. Augustinegrass. Commun. Soi l Sci. Plant Analysis 35:2357 2367. Camberato, J. 2001. Irrigation water quality. Clemson University Turfgrass Program. Clemson. 12 Apr. 2012. < http://www.scnla.com/Irrigation_Water_Quality. pdf >. Carlise, V.W. and R.B. Brown. 1982. Florida soil identification handbook. Univ. of Florida, Inst. Food Agr. Sci., Gainesville, FL.

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125 Carpenter, S.R., N.F. Caraco, D.L. Correll, R.W. Howarth, A.N. Sharpley, and V.H. Smith. 1998. Nonpoint pollution of surface waters with phosphorus and nitrogen. Ecol. Applications 8:559 568. Carrow, R.N. 1989. Managing turf for maximum root growth. Golf Course Mgt, Athens. < http://archive.lib.msu .edu/tic/gcman/article/1989jul18.pdf >. Chakraborty, D., V.D. Nair, M. Chrysostome, and W.G. Harris. 2011a. Soil phosphorus storage capacity in manure impacted Alaquods: Implications for water table management. Agr. Ecosystem Environ. 142:167 175. Chakrabor ty, D., V.D. Nair, W.G. Harris, and R.D. Rhue. 2011b. The potential for plants to remove phosphorus from the spodic horizon. Univ. Florida IFAS, Gainesville. 10 Feb. 2012. < http://edis.ifas.ufl.edu/ss560 >. Chr istians, N.E., D.P. Martin, and J.F. Wilkinson. 1979. Nitrogen, phosphorus, and potassium effects on quality and growth of Kentucky bluegrass and creeping bentgrass. Agron. J. 71:564 567. Chrysostome, M., V.D. Nair, W.G. Harris, and R.D. Rhue. 2007. Labora tory validation of soil phosphorus storage capacity predictions for use in risk assessment. Soil Sci. Soc. Amer. J. 71:1564 1569. Colclough, T. and P.M. Canaway. 1989. Fertilizer nutrition of sand golf greens III: Botanical composition and ground cover. J. Sports Turf Res. Inst. 65:55 63. Collins, M.E. 2010. Key to soil orders in Florida. Univ. of Florida, Inst. Food Agr. Sci. Gainesville. 7 May 2010. < http://edis.ifas.ufl.edu/ss113 >. Correll, D.L. 1998. The role of phosphorus in the eutrophication of receiving waters: A review. J. Environ. Qual. 27:261 266. Deconinck, F. 1980. Major mechanisms in formation of spodic horizons. Geoderma 24:101 128. Easton, Z.M. and A.M. Petrovic. 2004. Fertilizer source effect on ground and surface water quality in drainage from turfgrass. J. Environ. Qual. 33:645 655. Engelsjord, M.E. and B.R. Singh. 1997. Effects of slow release fertilizers on growth and on uptake and leaching of nutrients in Kentucky bluegrass turfs establish ed on sand based root zones. Can. J. Plant Sci. 77:433 444. Erickson, J.E., J.L. Cisar, G.H. Snyder, and J.C. Volin. 2005. Phosphorus and potassium leaching under contrasting residential landscape models established on a sandy soil. Crop Sci. 45:546 552. E rickson, J.E., D.M. Park, J.L. Cisar, G.H. Snyder, and A.L. Wright. 2010. Effects of sod type, irrigation, and fertilization on nitrate nitrogen and orthophosphate

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134 BIOGRAPHICAL SKETCH Drew McLean was born in Stuart, FL located on the south east coast of the state. Drew received a BS in Soil and Water Science from the University of Florida. While working on his BS degree Drew work as an OPS employee at the Analytical Research Laboratory locat ed at the University of Florida where his job duties included soil, water, plant tissue, and livestock waste sample digestions and prep work for further analysis. After earning his BS degree, he then obtained a laboratory technician position for TKN analy sis at the Analytical Research Laboratory. After working as a laboratory technician for some time he decided to go back to school to get his MS degree. He then joined the Soil and Water Science mater s program at the University of Florida under Dr. Amy Sho ber and Rex Ellis, where he investigated the use of spodic derived fill materials on the establishment on st. augustinegrass After earning his degree, Drew would like to apply what he has learned in the environmental job field.