Effects of aluminum (Al) from water treatment residual applications to pastures on mineral status of grazing cattle and ...

MISSING IMAGE

Material Information

Title:
Effects of aluminum (Al) from water treatment residual applications to pastures on mineral status of grazing cattle and mineral concentrations of forages
Series Title:
2009 Florida Beef Report
Physical Description:
Book
Creator:
Madison, Rachel
McDowell, Lee
O'Connor, George
Wilkinson, Nancy
Davis, Paul
Adesogan, Adegbola
Felix, Tara
Brennan, Megan
Publisher:
Institute of Food and Agricultural Sciences, University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Record Information

Source Institution:
University of Florida Institutional Repository
Holding Location:
University of Florida
Rights Management:
All rights reserved by the source institution and holding location.
System ID:
AA00000472:00001


This item is only available as the following downloads:


Full Text








Effects of Aluminum (Al) from Water Treatment Residual Applications to Pastures on
Mineral Status of Grazing Cattle and Mineral Concentrations of Forages

Rachel Madison1
Lee McDowell
George O'Connor
Nancy Wilkinson
Paul Davis
Adegbola Adesogan
Tara Felix
Megan Brennan


Al-Water Treatment Residuals applications to pastures in low to moderately high levels, help
alleviate environmental phosphorus contamination.


Summary
Amorphous aluminum (Al) hydroxides applied to
land in the form of water treatment residuals
(Al-WTR) can reduce soluble soil phosphorus
(P) concentrations in soils and thus can reduce
P contamination of the environment. Two
experiments of 145 or 148 d each using 36
grazing Holstein steers were conducted to
determine the effects of Al-WTR pasture
applications on mineral status of cattle and
mineral concentrations of bahiagrass (Paspalum
notatum). Treatments were replicated 3 times
each and were as follows: 1) control- no Al-
WTR application with steers receiving free-
choice mineral supplementation without P, 2)
control with free-choice mineral supplement
plus P, 3) treatment 1 with Al-WTR, and 4)
treatment 2 with Al-WTR. Total application of
Al-WTR over two yr was 169.5 tons dry
weight/ac on the pastures. In general, there
were few treatment effects on weight gains and
mineral concentrations in plasma, liver, bone
and forage mineral concentrations. Most forage
samples were deficient in sodium, copper,
selenium and cobalt and at various collection
dates deficient in calcium, phosphorus, iron and
zinc. The use ofAl-WTR applications is an


effective method of reducing P contamination
that does not adversely affect forage or cattle
mineral concentrations.

Introduction
There is an increasing public demand to reduce
the amount of phosphorus (P) transported to
water bodies due to the risk of eutrophication,
mainly from agricultural P-inputs, including the
land application of animal manure. Extensive
efforts have been focused on finding ways to
reduce soluble P in manure-impacted soils.
Aluminum (Al) binds to P and application of Al
could be one potential solution to the problem.
However, application of Al to the land can also
result in ingestion by livestock and potential
harm to animals.

Aluminum water treatment residuals (Al-WTR)
are the by-products of water purification
procedures. They may be one solution to the P
problem, in that the Al in the product will bind
with P, thus preventing leaching into
groundwater. Prior research from Florida has
shown that amending soils with Al-WTR
increases soil retention and reduces leaching of


2009 Florida BeefReport










P (O'Connor et al., 2002).
Two experiments were conducted to determine
the effects of pasture application of Al-WTR on
mineral status (primarily P) and performance of
grazing cattle. A second objective was to
evaluate the effects of the applied Al-WTR on
forage mineral concentrations.

Procedure
Two experiments were carried out in
consecutive yr, 2005 and 2006 using 36 grazing
Holstein steers for 145 or 148 d respectively.
Aluminum water treatment residuals (Al-
WTR) pasture applications were applied over
two yr totaling 169.5 tons dry weight/ac.

Steers were allotted (three/pasture) to one of
twelve 2.0 ac bahiagrass (Paspalum notatum)
pastures on d 0 and provided ad libitum water
and grazing access. Soil series that exist at this
location are Millhopper sand, Bonneau fine
sand, and Gainesville sand. Experimental
pastures were randomly allotted to one of four
treatments with three replications per treatment.
The Al-WTR product contained 0.30% iron
(Fe), 7.8% Al, 0.11% calcium (Ca), 0.024%
magnesium (Mg), 0.30% P, 0.004% manganese
(Mn), 0.73% sulfur (S), 0.006% copper (Cu),
0.002% zinc (Zn), and approximately 70%
solids. The treatments were 1) control-no Al-
WTR application with steers receiving
commercial free-choice mineral supplement but
no P, 2) control with free-choice mineral
supplement plus P, 3) treatment 1 with Al-WTR
and 4) treatment 2 with Al-WTR.

Weights, blood and liver biopsies were taken at
d 0, 84 and 148 and bone biopsies were obtained
on d 148. Forage samples were taken on d 0 and
approximately every 28 d thereafter for five mo.
Forage samples were analyzed for Al, Ca, Cu,
Fe, potassium (K), Mg, Mn, sodium (Na), P, Zn,
cobalt (Co) molybdenum (Mo) and selenium
(Se).

Data were analyzed for treatment effects using
Proc Mixed in SAS (SAS for Windows v9; SAS
Inst., Inc. Cary, NC) for a completely
randomized design with a 2x2 arrangement of
treatments. Contrasts (control vs. Al-WTR, no P
vs. P, and the interaction) were used for mean


separation. Significance was declared at P <
0.05.

Results
In general, differences in animal performance
among treatments were limited throughout the
experiment in both yr. In both experiments,
application of Al-WTR to pastures of grazing
ruminants to control environmental P was not
detrimental to the animal when considering BW
alone.

Plasma macrominerals (Ca, Mg and P)
concentrations were greater, in general, in
experiment 1. Yet, the microminerals (Al, Cu
and Zn) concentrations were generally greater in
experiment 2. Plasma P concentrations were
greater in experiment 1 than experiment 2 (6.02
vs. 5.18 mg/dL).

In both experiments, P plasma levels were
normal to low, but never reached a level of
deficiency at any collection. Therefore, the Al
in the Al-WTR did not complex with P enough
to cause a deficiency in the cattle during either
experiment. In both experiments, the Al plasma
concentrations were very low (0.02 gg/mL, on
average), indicating that the Al in Al-WTR may
be unavailable to the animal and safe to use on
pastures to reduce the P environmental problem.
In general, there were few treatment effects on
mineral concentrations in liver and bone.

Forage mineral concentrations as affected by Al-
WTR are presented in Tables 1 and 2.
Throughout the collection periods forage Ca
concentration was below or slightly above the
critical level of 0.35%. Using 0.18% P as a
critical level, both treatment groups produced
adequate forage P concentrations until
August/September for both experiments.
Magnesium, K and Mn forage concentrations
were adequate for both treatments during both
yr.
All forage Na concentrations were below the
critical level of 0.06% during both experiments.
All forage Cu concentrations were below the
critical level of 10 mg/kg in both experiments
and were lower, on average, in experiment 1.
Aluminum concentration were similar in
experiments 1 and 2 and varied by date (P<0.05)


2009 Florida BeefReport










in all but treatment 1 of experiment 2. Zinc
concentrations also varied by date in both
experiments and were similar between
treatments (P>0.05). Most Zn concentrations
were below the critical level of 30 mg/kg in both
experiments.

Only a limited number of samples were analyzed
for Co, Mo and Se. Forage Mo concentrations
means were not variable between treatments,
and generally low throughout all sampling
periods. Forage Mo concentrations ranged from
0.09 to 2.45 mg/kg and averaged 0.69 + 0.60
mg/kg. Over 99% of all Co samples taken were
below the critical concentration of 0.1 mg/kg.

Forage Se concentrations in this study were
extremely deficient and were all less than the
requirement of 0.1 mg/kg. Previous Florida
studies have shown the majority of forages to be
deficient in Na, P, Ca, Cu, Co, Se and Zn
(McDowell and Arthington, 2005).








Literature Cited
McDowell and Arthington. 2005. Minerals for Grazing Ruinants in Tropical Regions, IFAS/Animal
Sciences, Gainesville, FL.
O'Connor, et al. 2002. Soil Crop Sci. Soc. Florida Proc. 61:67.










'Rachel Madison, Former Graduate Student; Lee McDowell, Professor; Nancy Wilkinson, Chemist;
Paul Davis, Former Graduate Student; Adegbola Adesogan, Associate Professor; Tara Felix, Former
Graduate Student, UF/IFAS, Department of Animal Sciences, Gainesville, FL; George O'Connor,
Professor, UF/IFAS, Department of Soil and Water Science, Gainesville, FL; Megan Brennan, Assistant
Professor, UF/IFAS, Department of Statistics, Gainesville, FL.


2009 Florida BeefReport











Table 1. Forage minerals (dry basis) as affected by water treatment residuals (Experiment 1) 1-4
Trt5 May Jul Aug Sept Oct Nov Dec Means6 SD7
Ca, % 1 0.38a 0.30 b 0.27c 0.27c 0.28bc 0.32b 0.31bc 0.30 0.04
2 0.33b" 0.27bcd 0.31bcd 0.27bcd 0.26d 0.42a 0.35b 0.32 0.06
SD 0.04 0.20 0.03 0.00 0.10 0.07 0.03 0.01
K, % 1 1.38a 1.43b 1.33bc 0.82cd 1.09bc 2.14a 0.43d 1.23 0.50
2 1.51b 1.36bc 1.18b 1.02 1.09bc 2.09a 0.44d 1.24 0.47
SD 0.09 0.05 0.11 0.14 0.00 0.04 0.01 0.01
Mg, % 1 0.18ab 0.19 0.16b 0.16b 0.18ab 0.16b 0.13c 0.17 0.02
2 0.17bc 0.20a 0.19b 0.15 0.17 0.1 0.19b 0.15c 0.17 0.02
SD 0.01 0.10 0.02 0.01 0.01 0.02 0.01 0.00
Na, % 1 0.02abc 0.02abc 0.02abc 0.02abc 0.03a 0.03 0.01c 0.02 0.01
2 0.02b 0.02b 0.02b 0.01b 0.02b 0.04a 0.01b 0.02 0.01
SD 0.00 0.00 0.00 0.01 0.01 0.01 0.00 0.00
P, % 1 0.23a 0.23a 0.15b 0.14b 0.14b 0.14b 0.06c 0.16 0.05
2 0.22a 0.21a 0.17b 0.12b 0.14b 0.15b 0.06c 0.15 0.05
SD 0.01 0.01 0.01 0.01 0.00 0.01 0.00 0.01
Al, mg/kg 1 35.0b 65.3a 17.3c 36.1b 18.7c 26.2bc 17.7c 30.9 15.8
2 25.1bcd 31.9ab 15.8e 28.9bc 39.2a 37.4a 20.1cde 28.3 8.00
SD 7.0 23.6 1.06 5.09 14.5 7.92 1.70 1.84
Cu, mg/kg 1 9.69a 8.17bc 8.75ab 5.76d 6.18d 6.87cd 7.95bc 7.66 1.31
2 8.41a 8.23a 7.52a 5.32b 5.55b 8.48a 8.29a 7.39 1.27
SD 0.91 0.04 0.87 0.31 0.45 1.14 0.24 0.19
Fe, mg/kg 1 66.3a 59.1a 33.3b 34.3b 35.4b 54.9a 42.1b 44.5 12.48
2 43.9c 43.1bc 33.7c 36.7c 36.4c 66.6a 52.4bc 44.7 10.66
SD 15.8 11.3 0.28 1.70 0.71 8.27 7.28 0.14
Mn, mg/kg 1 78.3b 83.8ab 60.5c 56.5c 90.7ab 96.1a 95.1a 80.1 14.89
2 48.9c 49.7c 48.6c 48.3c 63.2b 70.0ab 79.6a 58.3 11.78
SD 20.8 24.1 8.41 5.80 19.4 18.5 11.0 15.4
Zn, mg/kg 1 34.4a 28.8b 28.7b 25.9bc 23.3cd 23.0cd 18.6d 26.1 4.73
2 43.9bc 43.1bc 33.7c 36.7c 36.4c 66.6a 52.4b 44.7 10.66
SD 6.72 10.1 3.54 7.64 9.26 30.8 23.9 13.2
a-eMeans with same letters within rows are not different (P<0.05).
'Water treatment residual contained 0.30% Fe, 7.8% Al, 0.11% Ca, 0.024% Mg, 0.30% P, 0.004%
Mn, 0.73% S, 0.006% Cu and 0.002% Zn.
2Critical concentrations are as follows: Ca, 0.35%; P, 0.18%; Mg, 0.10%; K, 0.60%; Na, 0.06%;
Cu, 10.0 mg/kg; Fe, 50.0 mg/kg; Mn, 20.0 mg/kg; Zn, 30.0 mg/kg (NRC, 1986; McDowell and
Arthington, 2005).
3Means represent 12 samples per month per treatment.
4In November for forage Ca, treatment with Al-WTR was lower (<0.05) than the control. In July
for forage Al, control treatment was lower (P<0.05) than treatment with Al-WTR.
5Treatments were as follows: 1) Al-WTR; 2) Control- no Al-WTR.
6Means of seven months of sampling
7SD = standard deviation


2009 Florida BeefReport












Table 2. Forage minerals (dry basis) as affected by water treatment residuals (Experiment 2) 1-4
Trt5 May Jun Jul Aug Sep Oct Means6 SD7
Ca, % 1 0.42a 0.32c 0.38ab 0.38ab 0.33c 0.37bc 0.37 0.04
2 0.37a 0.29c 0.31bc 0.36ab 0.39a 0.35ab 0.33 0.05
SD 0.04 0.20 0.05 0.01 0.04 0.01 0.03
K, % 1 1.49a 1.39ab 1.33b 0.31bc 1.23bc 1.21c 1.33 0.10
2 1.42a 1.96b 1.14b 1.40a 1.58a 1.45a 1.33 0.23
SD 0.05 0.30 0.13 0.06 0.25 0.17 0.00
Mg, % 1 0.18cd 0.20ab 0.19bc 0.21a 0.17d 0.19bc 0.19 0.01
2 0.18b 0.20a 0.18b 0.19ab 0.19ab 0.18b 0.19 0.01
SD 0.00 0.00 0.01 0.01 0.01 0.01 0.00
Na, % 1 0.02a 0.01b 0.02 a .02 0.02 a 0.02a 0.02 0.00
2 0.02 b 0.02b 0.01 a 0.02b 0.02 b 0.02b 0.02 0.00
SD 0.00 0.01 0.01 0.00 0.00 0.00 0.00
P, % 1 0.02 0.19 0.19 0.19 0.15 0.17 0.18 0.19
2 0.21a 0.21 0.19ab 0.19ab 0.18ab 0.17b 0.19 0.02
SD 0.01 0.01 0.00 0.00 0.02 0.00 0.01
Al, mg/kg 1 23.4cd 24.7cd 26.3bc 21.3d 33.7a 30.3ab 26.6 4.61
2 26.2cd 30.8bc 23.2d 27.5cd 40.5a 37.7ab 31.0 6.80
SD 1.98 4.31 2.19 4.38 4.81 5.23 3.11
Cu, mg/kg 1 9.54 a 8.33b 8.67b 8.41b 8.78b 7.63c 8.54 0.62
2 9.16a 9.27a 8.13bc 7.47c 8.39b 7.88c 8.35 0.71
SD 0.27 0.66 0.38 0.66 0.28 0.18 0.13
Fe, mg/kg 1 50.8ab 47.2b 54.5a 55.2a 48.4b 39.5c 49.3 5.75
2 58.5a 53.8a 44.8b 42.2b 43.8b 41.0b 47.4 7.10
SD 5.44 4.67 6.86 9.19 3.25 1.06 1.34
Mn, mg/kg 1 92.0a 69.1a 84.7a 64.8a 88.2a 142.4 90.2 27.76
2 55.7bc 58.9bc 40.6c 74.1b 90.1ab 93.3a 68.7 20.77
SD 25.7 7.21 31.2 6.58 1.34 34.7 15.2
Zn, mg/kg 1 37.4ab 26.3cd 31.5bc 19.8d 20.5cd 44.4a 30.0 9.72
2 25.5b 24.9b 21.0bc 29.1ab 15.7c 32.4a 24.8 5.90
SD 8.41 1.00 7.42 6.58 3.39 8.49 3.68
a-dMeans with same letter within rows are not different (P<0.05).
'Water treatment residual contained 0.30% Fe, 7.8% Al, 0.11% Ca, 0.024% Mg, 0.30% P, 0.004%
Mn, 0.73% S, 0.006% Cu and 0.002% Zn.
2Critical concentrations are as follows: Ca, 0.35%; P, 0.18%; Mg, 0.10%; K, 0.60%; Na, 0.06%;
Cu, 10.0 mg/kg; Fe, 50.0 mg/kg; Mn, 20.0 mg/kg; Zn, 30.0 mg/kg (NRC, 1986; McDowell and
Arthington, 2005).
3Means represent 12 samples per month per treatment.
4In November for forage Ca, treatment with Al-WTR was lower (<0.05) than the control. In July
for forage Al, control treatment was lower (P<0.05) than treatment with Al-WTR.
5Treatments were as follows: 1) Al-WTR; 2) Control- no Al-WTR.
6Means of seven months of sampling
7SD = standard deviation


2009 Florida BeefReport













































































128 2009 Florida BeefReport




Full Text

PAGE 1

Effects of Aluminum (Al) from Water Treatment Residual Applications to Pastures on Mineral Status of Grazing Cattle and Mineral Concentrations of Forages Rachel Madison 1 Lee McDowell Nancy Wilkinson Paul Davis Adegbola Adesogan Tara Felix Megan Brennan Summary Amorphous aluminum (Al) hydroxides applied to land in the form of water treatment residuals (Al-WTR) can reduce soluble soil phosphorus (P) concentrations in soils and thus can reduce P contamination of the environment. Two experiments of 145 or 148 d each using 36 grazing Holstein steers were conducted to determine the effects of Al-WTR pasture applications on mineral status of cattle and mineral concentrations of bahiagrass (Paspalum notatum). Treatments were replicated 3 times each and were as follows: 1) controlno AlWTR application with steers receiving freechoice mineral supplementation without P, 2) control with free-choice mineral supplement plus P, 3) treatment 1 with Al -WTR, and 4) treatment 2 with Al-WTR. Total application of Al -WTR over two yr was 169.5 tons dry weight/ac on the pastures. In general, there were few treatment effects on weight gains and mineral concentrations in plasma, liver, bone and forage mineral concentrations. Most forage samples were deficient in sodium, copper, selenium and cobalt and at various collection dates deficient in calcium, phosphorus, iron and zinc. The use of Al-WTR applications is an Introduction There is an increasing public demand to reduce the amount of phosphorus (P) transported to water bodies due to the risk of eutrophication, mainly from agricultural P-inputs, including the land application of animal manure. Extensive efforts have been focused on finding ways to reduce soluble P in manure-impacted soils. Aluminum (Al) binds to P and application of Al could be one potential solution to the problem. However, application of Al to the land can also result in ingestion by livestock and potential harm to animals. Aluminum water treatment residuals (Al-WTR) are the by-products of water purification procedures. They may be one solution to the P problem, in that the Al in the product will bind with P, thus preventing leaching into groundwater. Prior research from Florida has shown that amending soils with Al-WTR increases soil retention and reduces leaching of Al Water Treatment Residuals applications to pastures in low to moderately high levels, help alleviate environmental phosphorus contamination. effective method of reducing P contamination that does not adversely affect forage or cattle mineral concentrations.

PAGE 2

Two experiments were conducted to determine the effects of pasture application of Al-WTR on mineral status (primarily P) and performance of grazing cattle. A second objective was to evaluate the effects of the applied Al-WTR on forage mineral concentrations. Procedure Two experiments were carried out in consecutive yr, 2005 and 2006 using 36 grazing Holstein steers for 145 or 148 d respectively. Aluminum water treatment residuals (AlWTR) pasture applications were applied over two yr totaling 169.5 tons dry weight/ac. Steers were allotted (three/pasture) to one of twelve 2.0 ac bahiagrass ( Paspalum notatum) pastures on d 0 and provided ad libitum water and grazing access. Soil series that exist at this location are Millhopper sand, Bonneau fine sand, and Gainesville sand. Experimental pastures were randomly allotted to one of four treatments with three replications per treatment. The Al-WTR product contained 0.30% iron (Fe), 7.8% Al, 0.11% calcium (Ca), 0.024% magnesium (Mg), 0.30% P, 0.004% manganese (Mn), 0.73% sulfur (S), 0.006% copper (Cu), 0.002% zinc (Zn), and approximately 70% solids. The treatments were 1) control-no AlWTR application with steers receiving commercial free-choice mineral supplement but no P, 2) control with free-choice mineral supplement plus P, 3) treatment 1 with Al-WTR and 4) treatment 2 with Al-WTR. Weights, blood and liver biopsies were taken at d 0, 84 and 148 and bone biopsies were obtained on d 148. Forage samples were taken on d 0 and approximately every 28 d thereafter for five mo. Forage samples were analyzed for Al, Ca, Cu, Fe, potassium (K), Mg, Mn, sodium (Na), P, Zn, cobalt (Co) molybdenum (Mo) and selenium (Se). Data were analyzed for treatment effects using Proc Mixed in SAS (SAS for Windows v9; SAS Inst., Inc. Cary, NC) for a completely randomized design with a 2x2 arrangement of treatments. Contrasts (control vs. Al-WTR, no P vs. P, and the interaction) were used for mean separation. Significance was declared at P < 0.05. Results In general, differences in animal performance among treatments were limited throughout the experiment in both yr. In both experiments, application of Al-WTR to pastures of grazing ruminants to control environmental P was not detrimental to the animal when considering BW alone. Plasma macrominerals (Ca, Mg and P) concentrations were greater, in general, in experiment 1. Yet, the microminerals (Al, Cu and Zn) concentrations were generally greater in experiment 2. Plasma P concentrations were greater in experiment 1 than experiment 2 (6.02 vs. 5.18 mg/dL). In both experiments, P plasma levels were normal to low, but never reached a level of deficiency at any collection. Therefore, the Al in the Al-WTR did not complex with P enough to cause a deficiency in the cattle during either experiment. In both experiments, the Al plasma average), indicating that the Al in Al-WTR may be unavailable to the animal and safe to use on pastures to reduce the P environmental problem. In general, there were few treatment effects on mineral concentrations in liver and bone. Forage mineral concentrations as affected by AlWTR are presented in Tables 1 and 2. Throughout the collection periods forage Ca concentration was below or slightly above the critical level of 0.35%. Using 0.18% P as a critical level, both treatment groups produced adequate forage P concentrations until August/September for both experiments. Magnesium, K and Mn forage concentrations were adequate for both treatments during both yr. All forage Na concentrations were below the critical level of 0.06% during both experiments. All forage Cu concentrations were below the critical level of 10 mg/kg in both experiments and were lower, on average, in experiment 1. Aluminum concentration were similar in experiments 1 and 2 and varied by date ( P <0.05)

PAGE 3

in all but treatment 1 of experiment 2. Zinc concentrations also varied by date in both experiments and were similar between treatments ( P >0.05). Most Zn concentrations were below the critical level of 30 mg/kg in both experiments. Only a limited number of samples were analyzed for Co, Mo and Se. Forage Mo concentrations means were not variable between treatments, and generally low throughout all sampling periods. Forage Mo concentrations ranged from 0.09 to 2.45 mg/kg and averaged 0.69 0.60 mg/kg. Over 99% of all Co samples taken were below the critical concentration of 0.1 mg/kg. Forage Se concentrations in this study were extremely deficient and were all less than the requirement of 0.1 mg/kg. Previous Florida studies have shown the majority of forages to be deficient in Na, P, Ca, Cu, Co, Se and Zn (McDowell and Arthington, 2005). L iterature C ited McDowell and Arthington. 2005. Minerals for Grazing Ruinants in Tropical Regions, IFAS/Animal Sciences, Gainesville, FL. 1 Rachel Madison, Former Graduate Student; Lee McDowell, Professor; Nancy Wilkinson, Chemist; Paul Davis, Former Graduate Student; Adegbola Adesogan, Associate Professor; Tara Felix, Former Graduate Student, UF/IFAS, Department of Animal Sciences, G Professor, UF/IFAS, Department of Soil and Water Science, Gainesville, FL; Megan Brennan, Assistant Professor, UF/IFAS, Department of Statistics, Gainesville, FL.

PAGE 4

Table 1. Forage minerals (dry basis) as affected by water treatment residuals (Experiment 1) 1 4 Trt 5 May Jul Aug Sept Oct Nov Dec Means 6 SD 7 Ca, % 1 2 SD 0.38 a 0.33 bc 0.04 0.30 bc 0.27 bcd 0.20 0.27 c 0.31 bcd 0.03 0.27 c 0.27 bcd 0.00 0.28 bc 0.26 d 0.10 0.32 b 0.42 a 0.07 0.31 bc 0.35 b 0.03 0.30 0.32 0.01 0.04 0.06 K, % 1 2 SD 1.38 a 1.51 b 0.09 1.43 b 1.36 bc 0.05 1.33 bc 1.18 bc 0.11 0.82 cd 1.02 c 0.14 1.09 bc 1.09 bc 0.00 2.14 a 2.09 a 0.04 0.43 d 0.44 d 0.01 1.23 1.24 0.01 0.50 0.47 Mg, % 1 2 SD 0.18 ab 0.17 bc 0.01 0.19 a 0.20 a 0.10 0.16 b 0.19 ab 0.02 0.16 b 0.15 c 0.01 0.18 ab 0.17 bc 0.01 0.16 b 0.19 ab 0.02 0.13 c 0.15 c 0.01 0.17 0.17 0.00 0.02 0.02 Na, % 1 2 SD 0.02 abc 0.02 b 0.00 0.02 abc 0.02 b 0.00 0.02 abc 0.02 b 0.00 0.02 abc 0.01 b 0.01 0.03 a 0.02 b 0.01 0.03 a 0.04 a 0.01 0.01 c 0.01 b 0.00 0.02 0.02 0.00 0.01 0.01 P, % 1 2 SD 0.23 a 0.22 a 0.01 0.23 a 0.21 a 0.01 0.15 b 0.17 ab 0.01 0.14 b 0.12 b 0.01 0.14 b 0.14 b 0.00 0.14 b 0.15 b 0.01 0.06 c 0.06 c 0.00 0.16 0.15 0.01 0.05 0.05 Al, mg/kg 1 2 SD 35.0 b 25.1 bcd 7.0 65.3 a 31.9 ab 23.6 17.3 c 15.8 e 1.06 36.1 b 28.9 bc 5.09 18.7 c 39.2 a 14.5 26.2 bc 37.4 a 7.92 17.7 c 20.1 cde 1.70 30.9 28.3 1.84 15.8 8.00 Cu, mg/kg 1 2 SD 9.69 a 8.41 a 0.91 8.17 bc 8.23 a 0.04 8.75 ab 7.52 a 0.87 5.76 d 5.32 b 0.31 6.18 d 5.55 b 0.45 6.87 cd 8.48 a 1.14 7.95 bc 8.29 a 0.24 7.66 7.39 0.19 1.31 1.27 Fe, mg/kg 1 2 SD 66.3 a 43.9 c 15.8 59.1 a 43.1 bc 11.3 33.3 b 33.7 c 0.28 34.3 b 36.7 c 1.70 35.4 b 36.4 c 0.71 54.9 a 66.6 a 8.27 42.1 b 52.4 bc 7.28 44.5 44.7 0.14 12.48 10.66 Mn, mg/kg 1 2 SD 78.3 b 48.9 c 20.8 83.8 ab 49.7 c 24.1 60.5 c 48.6 c 8.41 56.5 c 48.3 c 5.80 90.7 ab 63.2 b 19.4 96.1 a 70.0 ab 18.5 95.1 a 79.6 a 11.0 80.1 58.3 15.4 14.89 11.78 Zn, mg/kg 1 2 SD 34.4 a 43.9 bc 6.72 28.8 b 43.1 bc 10.1 28.7 b 33.7 c 3.54 25.9 bc 36.7 c 7.64 23.3 cd 36.4 c 9.26 23.0 cd 66.6 a 30.8 18.6 d 52.4 b 23.9 26.1 44.7 13.2 4.73 10.66 a e Means with same letters within rows are not different (P<0.05). 1 Water treatment residual contained 0.30% Fe, 7.8% Al, 0.11% Ca, 0.024% Mg, 0.30% P, 0.004% Mn, 0.73% S, 0.006% Cu and 0.002% Zn. 2 Critical concentrations are as follows: Ca, 0.35%; P, 0.18%; Mg, 0 .10%; K, 0.60%; Na, 0.06%; Cu, 10.0 mg/kg; Fe, 50.0 mg/kg; Mn, 20.0 mg/kg; Zn, 30.0 mg/kg (NRC, 1986; McDowell and Arthington, 2005). 3 Means represent 12 samples per month per treatment. 4 In November for forage Ca, treatment with Al WTR was lower (<0.05) t han the control. In July for forage Al, control treatment was lower (P<0.05) than treatment with Al WTR. 5 Treatments were as follows: 1) Al WTR; 2) Control no Al WTR. 6 Means of seven months of sampling 7 SD = standard deviation

PAGE 5

Table 2. Forage minerals (dry basis) as affected by water treatment residuals (Experiment 2) 1 4 Trt 5 May Jun Jul Aug Sep Oct Means 6 SD 7 Ca, % 1 2 SD 0.42 a 0.37 a 0.04 0.32 c 0.29 c 0.20 0.38 ab 0.31 bc 0.05 0.38 ab 0.36 ab 0.01 0.33 c 0.39 a 0.04 0.37 bc 0.35 ab 0.01 0.37 0.33 0.03 0.04 0.05 K, % 1 2 SD 1.49 a 1.42 a 0.05 1.39 ab 1.96 b 0.30 1.33 b 1.14 b 0.13 0.31 bc 1.40 a 0.06 1.23 bc 1.58 a 0.25 1.21 c 1.45 a 0.17 1.33 1.33 0.00 0.10 0.23 Mg, % 1 2 SD 0.18 cd 0.18 b 0.00 0.20 ab 0.20 a 0.00 0.19 bc 0.18 b 0.01 0.21 a 0.19 ab 0.01 0.17 d 0.19 ab 0.01 0.19 bc 0.18 b 0.01 0.19 0.19 0.00 0.01 0.01 Na, % 1 2 SD 0.02 a 0.02 b 0.00 0.01 b 0.02 b 0.01 0.02 a 0.01 a 0.01 0.02 a 0.02 b 0.00 0.02 a 0.02 b 0.00 0.02 a 0.02 b 0.00 0.02 0.02 0.00 0.00 0.00 P, % 1 2 SD 0.02 0.21 a 0.01 0.19 0.21 a 0.01 0.19 0.19 ab 0.00 0.19 0.19 ab 0.00 0.15 0.18 ab 0.02 0.17 0.17 b 0.00 0.18 0.19 0.01 0.19 0.02 Al, mg/kg 1 2 SD 23.4 cd 26.2 cd 1.98 24.7 cd 30.8 bc 4.31 26.3 bc 23.2 d 2.19 21.3 d 27.5 cd 4.38 33.7 a 40.5 a 4.81 30.3 ab 37.7 ab 5.23 26.6 31.0 3.11 4.61 6.80 Cu, mg/kg 1 2 SD 9.54 a 9.16 a 0.27 8.33 b 9.27 a 0.66 8.67 b 8.13 bc 0.38 8.41 b 7.47 c 0.66 8.78 b 8.39 b 0.28 7.63 c 7.88 c 0.18 8.54 8.35 0.13 0.62 0.71 Fe, mg/kg 1 2 SD 50.8 ab 58.5 a 5.44 47.2 b 53.8 a 4.67 54.5 a 44.8 b 6.86 55.2 a 42.2 b 9.19 48.4 b 43.8 b 3.25 39.5 c 41.0 b 1.06 49.3 47.4 1.34 5.75 7.10 Mn, mg/kg 1 2 SD 92.0 a 55.7 bc 25.7 69.1 a 58.9 bc 7.21 84.7 a 40.6 c 31.2 64.8 a 74.1 b 6.58 88.2 a 90.1 ab 1.34 142.4 93.3 a 34.7 90.2 68.7 15.2 27.76 20.77 Zn, mg/kg 1 2 SD 37.4 ab 25.5 b 8.41 26.3 cd 24.9 b 1.00 31.5 bc 21.0 bc 7.42 19.8 d 29.1 ab 6.58 20.5 cd 15.7 c 3.39 44.4 a 32.4 a 8.49 30.0 24.8 3.68 9.72 5.90 a d Means with same letter within rows are not different (P<0.05). 1 Water treatment residual contained 0.30% Fe, 7.8% Al, 0.11% Ca, 0.024% Mg, 0.30% P, 0.004% Mn, 0.73% S, 0.006% Cu and 0.002% Zn. 2 Critical concentrations are as follows: Ca, 0.35%; P, 0.18%; Mg, 0.10%; K, 0.60%; Na, 0.06%; Cu, 10.0 mg/kg; Fe, 50.0 mg/kg; M n, 20.0 mg/kg; Zn, 30.0 mg/kg (NRC, 1986; McDowell and Arthington, 2005). 3 Means represent 12 samples per month per treatment. 4 In November for forage Ca, treatment with Al WTR was lower (<0.05) than the control. In July for forage Al, control treatment w as lower (P<0.05) than treatment with Al WTR. 5 Treatments were as follows: 1) Al WTR; 2) Control no Al WTR. 6 Means of seven months of sampling 7 SD = standard deviation