Group Title: Research report - North Florida Research and Education Center ; 88-2
Title: Date of corn planting in relation to biological nitrogen production
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00066068/00001
 Material Information
Title: Date of corn planting in relation to biological nitrogen production
Series Title: Research report (North Florida Research and Education Center (Quincy, Fla.))
Physical Description: 13 pages : ill. ; 28 cm.
Language: English
Creator: Wright, D. L ( David L )
North Florida Research and Education Center (Quincy, Fla.)
Publisher: North Florida Experiment Station
Place of Publication: Quincy Fla
Publication Date: 1988
Subject: Corn -- Planting   ( lcsh )
No-tillage   ( lcsh )
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
Bibliography: Includes bibliographical references.
Statement of Responsibility: by D.L. Wright ... et al..
General Note: Caption title.
 Record Information
Bibliographic ID: UF00066068
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 71127176

Table of Contents
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
Full Text

Date of Corn Planting in Relation to Biological L:
Nitrogen Production-/

D. L. Wright, I. D. Teare, R. L. Stanley, Jr.,.

B. T. Kidd, and N. R. Usherwood, ...


No-tillage planting of corn into legume cover crops has many of the ad-

vantages of grass cover crops such as protection of soil from wind and water

erosion but also provides biologically fixed N to nonlegumes in the cropping

system. The purpose of this study was to determine optimum corn (Zea mays L.)

planting date in relation to biologically fixed N from crimson clover (Trifol-

ium incarnatum L.). Field experiments were conducted in 1981 and 1982 on a

Norfolk sandy loam soil (Typic Paleudult). Corn was planted with a ripper

minimum till planter (Brown-Ro-Til) into crimson clover mulch at planting

dates from late February to mid-April.

Planting date affects resultant grain yields of corn. The highest grain

yields were obtained at the earliest planting date (mean of 10.4 Mg ha ) and

the lowest at the last planting date (mean of 3.9 Mg ha1 ) over both years.

However, legume dry matter yields varied from the highest (3.2 Mg ha ) in

1980 when corn plantings were started in April to the lowest (0.5 Mg ha-1) in

1981 when plantings were made earliest. In 1982, total tissue N uptake at

1/Research Report No. NF 88-2 from North Florida Research and Education

Center, Quincy, FL 32351, University of Florida. Agricultural Experiment

Station, Institute of Food and Agricultural Sciences.

/ Professor, Research Scholar/Scientist, Associate Professor of Agronomy,

University of Florida, Vice President, Potash and Phosphate Institute,

Atlanta, GA., and Biological Scientist II, University of Florida.

maturity in corn was 125, 150, and 175 kg ha1 for planting date 1, 2, and 3,

respectively, however, tissue concentration was similar (1.0%) and low in all

planting dates at harvest. Nitrogen produced by the legumes at the earliest

planting date was sufficient to produce highest grain yields each year though

plants were visibly N deficient soon after plants reached a height of 0.5 m.

Corn grain yields were highest at the earliest planting dates when legume dry

matter was lowest. This suggests that grain yield reduction was not due to a

shortage of N and that factors that result in higher corn yields from early

planting are more critical than the N supplied by the legumes.

Additional index words: Crimson clover (Trifolium incarnatum L.), Biological

N, No-tillage, Planting date.


Research from the Southeast USA has shown that corn can be produced suc-

cessfully without preparing a conventional seedbed (Touchton and Stevenson,

1984). Production practices proven under conventional seeding should also

result in best yields when planted under no-till conditions. Corn planted as

soon as soil temperatures allow germination in the spring, usually results in

highest yields and grain quality (Teare et al., 1987; Touchton et al., 1982).

As no-till becomes more accepted as a normal planting routine by growers,

questions arise about N production from legume cover crop. Several years ago,

legumes were used as green manure crops to improve soil tilthand to produce N

for subsequent crops. There is a renewed interest in legumes as a mulch cover

for no-till plantings of corn and grain sorghum to provide some N along with

benefits of the mulch cover. Touchton et al. (1982) found that crimson clover

(Trifolium incarnatum L.) produced enough N to produce as much grain sorghum

(Sorghum bicolor L. Moench) as 135 kg ha1 of commercial N. Grain sorghum

requires a soil temperature of 18-200C for germination, as compared to about

12-130C for corn, and successful plantings are often made near maturity of

crimson clover (mid-April). However, when legumes are used to supply N for

early planted corn, legumes are often in a young, vegetative stage of growth

and have not had sufficient time to produce maximum dry matter yields. Doll

and Link (1957) found that legumes produce more total N if allowed to grow to

maturity (maximum dry matter accumulation). When crimson clover is used for

mulch in no-till corn, maximum dry matter accumulation occurs about 40 to 55

days after the recommended period (April 10 April 20) for planting corn in

the Southeast USA (Wesley, 1979). Mitchell and Teel (1977) measured the

influence of various grass and legume cover crops on corn yields and found

that corn planted into a legume cover crop without commercial N yielded as

well as corn planted into a grass cover crop with 112 kg ha" of applied N.

There is little difference in establishment cost of grass or legume cover

crops and their value for holding soil against wind and water erosion is

similar. However, legumes do have the advantage of N fixation when properly

inoculated. Touchton (1980) noted that the value of N from legumes was ap-

proximately equal to the establishment cost ($20), but other benefits such as;

1) less soil and nutrient loss and 2) better soil tilth are accrued and are

difficult to assess in value. When grain sorghum is planted into a mature

stand of crimson clover, the clover may naturally reseed under favorable

environmental conditions to the extent that no replanting of the clover is

necessary for several years making it an excellent choice as a cover crop

(Duncan, 1980). However, when corn is planted into a mulch crop the legume is

in the vegetative stage and this does not permit seed production for natural

reseeding. Since recommended corn planting dates do not allow legumes to

accumulate maximum dry matter yields, these experiments were conducted to

relate the optimum planting date of corn to amount of nitrogen produced by the

symbiotic relationship between crimson clover and rhizobia fixation of nitro-

gen and dry matter accumulation.

Materials and Methods

Legumes were established in the fall of each year from 1979 through 1981

on a Norfolk sandy loam soil (Typic Paleudult) located at Quincy Agricultural

Research and Education Center in the Southeast Coastal Plain. The cropping

history of the experimental area was a wheat-soybeans double crop system for

each of the previous two years. Initial pH was 5.8 and fertility levels were:

P,20 = 190 kg ha-1, K 0 = 200 kg ha-1, CaO = 720 kg ha- and MgO = 310 kg ha-1

as measured by soil test (double acid extraction). In each of the 3 years

prior to planting crimson clover, the area was harrowed and fertilized. Fer-

tilizer was incorporated to 150 mm soil depth at the rate of 448 kg ha- of

3-9-18 in the fall prior to planting. Inoculated crimson clover seeds were

hand seeded at 22.4 kg ha~ after 15 October. Seed were cultipacked immedi-

ately after planting to obtain better soil-seed contact. An application of

12.4 mm of water was applied to the experimental area after planting to aid

germination and to promote early legume growth. Crimson clover was allowed to

grow until just prior to corn planting time when clippings were made for dry

matter yield.

Approximately 5 days before each corn planting date, 0.9 L ha- of para-

quat (1, 12 dimethyl 4, 4' bipyridinium ion) was sprayed on crimson clover

in 350 L of H20 containing 0.5% non-ionic surfactant (X-77) to eliminate com-

petition to the corn crop. Corn was overplanted by 15% in 760 mm wide rows to

attain a final population of 74 000 plants ha-. Atrazine (2 chloro-4-ethyl-

amino-6-isopropyl amino-l, 3, 5-triazine) and either metolachlor (2-methozy-l-

methylethyl acetamide) or alachlor(2-chloro-2-6-diethyl-N-(methoxy-methyl)

acetanilide) were used as the grass herbicide as an "over-the-top" broadcast

spray when the corn was 0.13 m tall. Corn hybrids used were Ring Around 1502

in 1980 and DeKalb XL71 in 1981 and 1982 which had shown high yield potential

in state yield trials. Both hybrids mature in 100 to 110 days. Corn seed was

planted with a no-till, subsoil unit planter and subsoiling was accomplished

to a depth of 300 mm. Carbofuran (2, 3-Dihydro-2, 2-dimethyl-7- benzofuramyl

methylcarbamate) was applied in a 150 mm band over the row for insect and

nematode control at the rate of 2.2 kg of a.i. ha-1. Corn planting dates were

11 April, 1 May, and 15 May in 1980; 25 February, 27 March, and 17 April in

1981; 5 March, 30 March, and 14 April in 1982.

Following planting, 112 kg ha- of P20,, 224 kg ha~ of K20, 7 kg ha~ of

Zn and 7 kg ha- of Mn were applied over the row. Tensiometers were installed

in rows between plants and maintained throughout the experimental area.

Irrigation water was applied when soil tensiometer readings reached .02 MPa.

Experimental design was a split plot with planting date as main plots and

years the sub plots. Each plot was 9.1 m long replicated 4 times consisting

of 8 rows 760 mm apart. Harvests were made from 4.6 m of the middle two rows

to minimize the border effects. The standard error of the treatment means

were calculated and illustrated in Fig. 2.

Harvested corn yields were corrected to 15.5% moisture. Whole plant

samples were taken to determine N uptake and concentration at four plant

growth stages (0.5 m ht., 1.2 m ht., tasselling and maturity) by kjeldahl

analysis procedures.

Results and Discussion

The effects of corn planting dates on corn grain yields are shown in Fig.

1. Highest corn grain yields were consistently made at the earliest planting

date. Highest grain yield for Ring Around 1502 (1980) was 9.6 Mg ha1 at the

earliest planting date. This planting date corresponded to the last planting

date in the two succeeding years with DeKalb XL71. This is attributed to the

excellent growing conditions encountered for the legumes in March of 1980 when

258 mm of rainfall fell as compared to 170 mm and 111 mm in 1981 and 1982,

respectively and resulted in more legume dry matter production (Fig. 2).

Crimson clover accumulated about 2.5 Mg ha~ dry matter by mid-April of (1981,

1982, 1983) which corresponds with its maturity date. In 1980, crimson clover

accumulated 3.5 Mg ha1 DM by mid April. Crimson clover did not accumulate

any additional dry matter after mid-April and was in a state of decomposition

at the late April and mid-May planting dates. However, corn grain yields

decreased at each successive date, therefore, it was decided to "dare the

frost" for studies in 1981 and 1982, with the third planting at maturity of

crimson clover. Grain yields from corn planted early into crimson clover in

1981 and 1982 were about 10.5 Mg ha-. Each of the following planting dates

resulted in a sharp drop in grain yield to less than 6 Mg ha- for the April

plantings. We interpretated this data for the three years to be an indica-

tion that early planting of corn is highly desirable regardless of the legume

dry matter accumulation.
Nitrogen Uptake in Corn Tissue

Nitrogen uptake in corn at four growth stages is a quantitative measure of

nitrogen availability in relation to crimson clover dry matter accumulation

and N fixation. Total N uptake by corn at 0.5 m height in 1982 was about 25

kg ha"1. By maturity, the earliest planted corn had a total N uptake of about

125 kg ha1 which compared to 150 and 175 kg ha1 of N for the second and

third planting dates at maturity, respectively. The difference in total N

uptake was attributed to the amounts of dry matter produced in early March as

compared to mid April. Using 20% crude protein as an average value for the

March through May period for crimson clover (L. S. Dunavin, personal communi-

cation) and 0.6 Mg ha-1 dry matter for early March and 2.5 Mg ha1 dry matter

for mid-April, 19.2 and 80.0 kg ha1 of N were produced in the legume biomass

by the 5 March and 14 April planting of corn, respectively. Since higher

amounts of N were available for corn growth at the later planting dates, more

N was taken up as noted in Figure 3. Residual soil N and N fixed in rhizobia

were not measured in the total N uptake of corn since uptake was much higher

than the total amount extracted in the top growth of the legumes. According

to Jones (1967), tissue N concentration was below the critical level (2.25%

indicating nitrogen deficiency) for corn planted at any date for most of the

season. Visual observations of N deficiency (yellow leaf tips and light green

plants) were noted throughout the growing season and substantiated tissue

tests that corn N deficiency started at 0.45 m plant height and became

progressively more severe as corn matured. Olson and Kurtz (1982) found that

N concentration for whole plant samples was less than for the ear leaf sample

and that the critical N concentration for whole plants was 1.9%. Using this N

concentration as a guide to determine when corn became deficient, data shown

in Figure 3 suggests that the period between 0.5 and 1.2 m would be important

for additional sidedress N applications. Nitrogen concentration in corn

tissue decreased rapidly from 0.5 m plant height to maturity in each planting

date even though more N was available from increased legume dry matter yields

at the April planting date. Tissue N concentration was similar and low (about

1%) for all planting dates as corn matured. In spite of the low N concentra-

tion found in corn tissue at maturity, no visual ear malformation was noted

for any planting into the legumes.

Where legumes are allowed to grow to maturity, significant amounts of N

can be fixed to meet the N requirements for a grass crop in the cropping

system (Dunavin, 1982). When legumes are used as a cover crop for N fixation

in corn production, earliness of corn planting is more critical to optimum

grain yields than the value of added N fixed when legumes were allowed to


Other significant benefits derived from using legumes as cover crops in-

clude erosion control, less leaching of nutrients, and decreased water evapor-

ation after stands are chemically killed (Ebelher et al. 1984). The N pro-

duced by the legume during the vegetative stage of growth is rapidly released

upon chemically killing (Hargrove and Wilson, 1984) and is available for corn

growth within a couple of weeks after planting. Nitrogen requirements for

corn are generally higher after corn reaches heights of 0.5 m or more.

Therefore, where legumes are used to supply part of the N requirement, supple-

mental N applications should begin when corn reaches a height of 0.5 m or soon

thereafter. In using legume cover crops, the highest priority should be

placed on planting corn at its optimum planting date, rather than striving for

optimum dry matter production of the legumes.


Doll, E. C., and L. A. Link. 1957. Influence of various legumes on the

yields of succeeding corn and wheat and nitrogen content of the soil.

Agron. J. 49:307-309.

Dunavin, L. S. 1982. Vetch and clover overseeded on a bahiagrass sod.

Agron. J. 74:793-796.

Duncan, R. R. 1980. General sorghum production practices. p. 1-3. In R. R.

Duncan (ed.). Proc. Sorghum Short Course. Univ. of Georgia Spec. Pub.

No. 6.

Ebelhar, S. A., W. W. Frye, and R. L. Blevins. 1984. Nitrogen from legume

cover crops for no-tillage corn. Agron. J. 76:51-55.

Hargrove, W. R., and D. O. Wilson. 1984. Winter legumes as a nitrogen source

for no-till grain sorghum. Agron. Abst. p. 74.

Jones, J. B., Jr. 1967. Interpretation of plant analysis for several

agronomic crops. p. 49-58. In soil testing and plant analysis. Special

Pub. Ser. No. 2. Soil Science Soc. Am., Madison, Wis.

Mitchell, W. H., and M. R. Teel. 1977. Winter-annual cover crop for no-till

corn production. Agron. J. 69:569-573.

NRC. 1984. Nutrient requirements of beef cattle (6th Ed.). National Academy

Press. Washington, D.C. p. 50.

Olson, R. A., and L. T. Kurtz. 1982. Crop nitrogen requirements, utiliza-

tion, and fertilization, p. 567-604. In F. J. Sevenson (ed.). Nitrogen

in agricultural soils. Agronomy Monograph Pub. No. 22. Madison, Wis.

Touchton, J. T. 1980. Soil fertility management for grain sorghum pro-

duction. p. 4-12. In R. R. Duncan (ed.). Proc. Sorghum Short Course.

Univ. of Georgia Spec. Pub. No. 6.

Touchton, J. T., W. A. Gardner, W. L. Hargrove, and R. R. Duncan. 1982.

Reseeding crimson clover as a N source for no-tillage grain sorghum

production. Agron. J. 74:283-287.

Touchton, J. T. and R. E. Stevenson. 1984. Proceedings of 7th Ann.

No-tillage Sys. Conf., Auburn, Ala.

Wesley, W. K. 1979. Irrigated corn production and moisture management.

Univ. of Georgia. College of Agric. Bull. No. 820.

Wright, D. L., I. D. Teare, and B. T. Kidd. 1987. Phenological events of

corn in relation to time of planting. IFAS, Agric. Exp. Stn. Research

Report No. NF 87-3:1-12.


.- "^'^- 1982
0 ;-:- --:

E Pd 1 Pd 2 Pd 3

Planting Date

Figure 1. Corn grain yield in relation to planting date using
crimson clover as a biological source of N in 1980, 1981, and

'-"------1981 20 ="
I0 0

U, 40

Pd Pd2 Pd 3

Planting Date
Figure 2. Crimson clover phytomass and total clover N in relation
to planting date prior to planting no-till corn for 1981 and
1982. Total N in crimson clover was ob-
tained by multiplying phytomass by20

Pd 1 Pd 2 Pd 3
Planting Date
Figure 2. Crimson clover phytomass and total clover N in relation
to planting date prior to planting no-till corn for 1981 and
1982. Total N in crimson clover prior to planting was ob-
tained by multiplying phytomass by 3 18.-4% CP)
( 6.15


--_- 1.2 m
S.0 Tassel

Pd 1 Pd 2 Pd 3
Planting Date
Figure 3. Nitrogen content of whole corn plant at four growth stages
(5 March, 30 March, and 14 April) in 1982. Tissue N concentration
considered critical when below 2.25%.

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs