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INTEGRATED SOIL AND CROP MANAGEMENT

Cover Crops and Nutrient Retention for Subsequent Sweet Corn Production

^a Dep. of Plant Sci., Macdonald Campus of McGill Univ., 21,111 Lakeshore Rd., Ste. Anne de Bellevue, QC, H9X 3V9, Canada
^b Inst. de Malherbologie, P.O. Box 222. Ste. Anne de Bellevue, QC, Canada

afm{at}nrs.mcgill.ca

	ABSTRACT

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results Discussion REFERENCES

 
The use of high rates of N fertilizer in intensive sweet corn (Zea mays L.) production may result in leaching losses and contamination of adjacent waterways and ground water. Cover crops planted after sweet corn harvest could absorb residual soil N and minimize losses of fertilizer in gravitational water. Field experiments were conducted on a Ste. Rosalie heavy clay (fine, mixed, frigid, Typic Humaquept) and a St. Bernard sandy clay loam (fine loamy, mixed, nonacid, frigid Typic Eutrochrept). Cover crop effects on nutrient uptake, subsequent N release, loss of N, P, and K in leaching water, and denitrification rates were measured. Fertilizer N rates were 0, 75, and 150 kg ha^-1. Cover crops were red clover (Trifolium pratense L.), crimson clover (Trifolium incarnatum L.), forage radish (Raphanus sativus L.), canola (Brassica rapa L.), barley (Hordeum vulgare L.), and annual ryegrass (Lolium multiflorum L.). A control treatment with no cover crop was also included. Three replicates were used in a split-plot arrangement of a randomized complete block design. Fall residual soil NO^-₃–N levels were higher in control plots than cover crop plots. Gravitational water NO^-₃–N was greater in control plots and ranged from 17 to 76 kg N yr^-1 N, compared with cover crop plot values of 1 to 55 kg N yr^-1. Cover crops had no effect on denitrification rates, or on NH⁺₄–N, P, or K concentrations in gravitational water. Forage radish, canola, and barley were effective cover crops in reducing soil NO^-₃–N. Cover crop effects on subsequent sweet corn were found only in grain N uptake.

	INTRODUCTION

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results Discussion REFERENCES

 
NUTRIENT LOSS

from the soil during crop production has adverse effects on soil properties and is an economic loss. Ground and surface water contamination can be caused by plant nutrients applied in excess of crop uptake. Nitrogen management goals are to promote N uptake and maximize crop yield while minimizing N losses. Losses of mineral N are a result of immobilization, volatilization of NH₃, leaching, and denitrification (Bock, 1984). These last two processes are of concern as potential sources of contaminants of ground and surface waters and of the atmosphere. Sweet corn in eastern Canada may be a problem crop due to high N fertilizer rates.

Growing cover crops after sweet corn harvest may minimize residual soil NO^-₃–N level and reduce NO^-₃–N content of gravitational water (Karlen and Doran, 1991; Miller et al., 1992; Brandi-Dohrn et al., 1997). Legumes are difficult to study as they are both a sink and a source of N. Nitrogen supplied by hairy vetch (Vicia villosa Roth) and crimson clover (Trifolium incarnatum L.) in cover crop experiments ranged from 72 to 149 kg N ha^-1 (Ebelhar et al., 1984; Hargrove, 1986; Holderbaum et al., 1990; Clark et al., 1995; McVay et al., 1989). Nonlegume cover crops have been associated with reducing N leaching loss, but the equivalent fertilizer N retained against leaching is estimated with difficulty. Studies of legume vs. nonlegume cover crops are needed in order to compare their capacity to decrease soil NO^-₃–N and release N to the subsequent crop.

The denitrification process in agricultural soils is affected by NH⁺₄–N and NO^-₃–N concentrations (De Klein and van Logtestijn, 1994), water content (Davidson, 1992), available C content (Rolston, 1981), and temperature (Mancino et al., 1988). Incorporation of available C from cover crops can increase denitrification rates (Aulakh et al., 1983). Production of crops such as sweet corn, which have high N rates and early maturity, might benefit from the use of cover crops to absorb excess fertilizer N in the late summer and fall growth. The objectives of the study were to quantify the effect of N fertilizers and cover crop species on subsequent sweet corn yield, N uptake, potential nutrient losses in gravitational water, and denitrification.

	Materials and methods

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The experiments were conducted at two sites, the Ste. Rosalie site at the Lods Experimental Agronomy Centre and the St. Bernard site at the Horticulture Centre, both on the Macdonald Campus of McGill University (45°25'45'' N, 73°56'00'' W) (Table 1) . Average precipitation is 929 mm yr^-1 and mean annual temperature is 6.2°C.

Two liters per hectare of Basagran [480 g L^-1 bentazon; 3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] was applied on 22 June 1994, to control nut sedge (Cyperus rotundus L.) on the Ste. Rosalie site. In April 1995 and June 1996, the Ste. Rosalie plots were sprayed with 5 L ha^-1 Roundup [356 g L^-1 glyphosate, N-(phosphonomethyl)glycine] directed between the rows, 2.8 L ha^-1 Hoe-grass 284 {284 g L^-1 diclofop-methyl; methyl ester of (±)-2-[4-(2,4-dichlorophenoxy)phenoxy]propanoic acid}, 1 L ha^-1 Pardner (280 g L^-1 bromoxynil; 3,5-dibromo-4-hydroxybenzonitrile), and 2.25 L ha^-1 Basagran Fort (480 g L^-1 bentazon). Herbicides were applied post emergence. No herbicides were used in the St. Bernard site. Corn was harvested by hand on 5 Aug. 1994, 24 July 1995, and 20 July 1996; 25 ears were randomly harvested from the central two rows and a five-plant subsample was taken from each plot to assess yield components. Samples were dried at 70°C and ground to pass a 1-mm sieve (18 mesh) prior to analyses.

Experimental areas were cultivated with a tractor-mounted rototiller before seeding cover crops. Six cover crops and a control treatment (no cover crop) were used. Cover crops were seeded on 8 and 10 Sept. 1994 and 5 and 6 Sept. 1995, using a 5-row, 76-cm small-plot forage seeder. Cover crop seeding rates were 12 kg ha^-1 for red clover, 22 kg ha^-1 for crimson clover, 10 kg ha^-1 in 1994 and 20 kg ha^-1 in 1995 for forage radish, 10 kg ha^-1 for canola, 142 kg ha^-1 for barley, and 35 kg ha^-1 for annual ryegrass. Forage radish seeding rate was increased to 20 kg ha^-1 in 1995, due to low plant populations in 1994.

Harvesting of cover crop biomass was completed on 28 October in 1994 and on 25 October in 1995, using a 53.4- by 53.4-cm quadrat. Due to unusual conditions, the cover crop continued to grow in 1994 after sampling. Ten plants were dug from each plot to estimate root and shoot biomass and NPK concentrations. Plant roots were removed with help of a small shovel, and washed carefully to remove the soil. All plant samples were dried at 70°C and weighed. Plots were plowed after sampling. Treatments were repeated in time in the same plots throughout the study.

Soil NO₃ and gravitational water measurements were carried out only on high N rate plots, on forage radish, red clover, ryegrass, and control plots. Samples for NO₃–N were obtained before sweet corn seeding in spring and in late fall when cover crop growth ceased. Samples at the Ste. Rosalie site were taken to a depth of 100 cm in 20-cm increments; samples at the St. Bernard site were taken to a depth of 60 cm in 20-cm increments.

Zero-tension lysimeters were installed to collect gravitational water in November and removed in early May. Sampling cylinders (6.0 cm i.d. by 90 cm) with one closed end and three holes (0.3 cm diam.) were installed in the selected treatment plots, with three replicates, after sweet corn harvest for both sites in 1994 and 1995. Cylinders were pushed into the soil to 55 cm below the soil surface after removing soil with hydraulically inserted sampling tubes of the same diameter. The open end of the cylinder was covered with a glass jar to prevent precipitation entry and evaporation. Soil water at zero tension could enter but not leave the cylinder. Soil solution samples were collected periodically whenever water was found from the cylinder with a rubber hose connected to a 60-mL syringe. Both rubber hose and syringe were washed with distilled water after each sample and rinsed with the next sample to minimize contamination. At each sampling, approximately 70 mL of soil solution was collected from each cylinder for determination of NO^-₃–N, NH⁺₄–N, P, and K on 28 Mar. 1995, 22 Jan. 1996, 2 May 1996, and 8 May 1996.

Denitrification measurements were made during the corn growing season using the technique of Aulakh et al. (1983). Soil cores (2.5 cm i.d. by 15 cm) were collected from the 0- to 15-cm depth from forage radish, red clover, ryegrass, and control plots and were incubated in 2-L bottles at ambient temperatures. The concentration of N₂O was determined on gas samples from incubated soil by gas chromatography.

Soil samples were extracted using the Mehlich 3 procedure (Tran and Simard, 1993); P and K were determined with an automated analyzer. Organic matter analyses used the Walkley–Black procedure (Nelson and Sommers, 1982). Soil particle size distribution was measured by hydrometer (McKeague, 1976, p. 16–26).

The mineral N lost from the profile during the fall and winter of 1994–1995 and 1995–1996 was calculated using changes in soil NO₃ and estimated leaching losses from gravitational water assuming leaching losses of 215 to 236 mm of excess water (Zhang and MacKenzie, 1997). Ammonium and NO^-₃–N were extracted from approximately 10 to 15 g of soil from each depth by shaking in 100 mL of 1 M KCl for 1 h. Suspensions were filtered and filtrates analyzed colorimetrically (Keeney and Nelson, 1982). Plant total N, P, and K were determined by digesting 0.250 g of oven-dry plant tissue using H₂SO₄ and H₂O₂ and determining N and P colorimetrically and K by flame photometry (Thomas et al., 1967).

Statistical analyses were conducted using Analysis of Variance (ANOVA) and General Linear Model (GLM) procedures of Windows SAS Version 6.11 (SAS Institute, Cary, NC). Comparisons among treatments were made using orthogonal contrasts. Polynomial trend comparisons were used to examine N treatment effects.

	Results

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Sweet Corn Dry Matter Production and Grain N Uptake
The effect of N and cover crop treatments on sweet corn was limited to grain N contents (Table 2) . Cover crops did not affect sweet corn dry matter production (data not shown). Block effects were found at one location year due to variation in site properties.

Cover Crop Dry Matter Production
Cover crop root and shoot yields varied with species, except for the Ste. Rosalie shoot biomass in 1994 (Table 3) . Shoot biomass at the St. Bernard site in 1994 was highest from barley and ryegrass, followed by forage radish, canola, and red and crimson clover. Estimated root biomass in 1994 was highest for ryegrass at both sites. In 1995, shoot biomass ranged from 255 to 3120 kg ha^-1. Cover crop species effects were similar across both sites. Forage radish produced the highest shoot and root biomass; red clover produced the lowest aboveground biomass.

Cover Crop N Uptake
Cover crop N uptake paralleled dry matter production at both sites for both years. There was no effect of N fertilizer in either year at either site (Table 4) . Root and shoot N uptake was affected by cover crop species excepted for shoot N in 1994 at the Ste. Rosalie site. At the St. Bernard site, shoot N uptake was higher with barley, ryegrass, forage radish, and canola and lower with crimson and red clover. In 1995, forage radish had the highest total shoot and root N at both sites, followed by canola at the Ste. Rosalie site, and canola and barley shoot values at the St. Bernard site.

Denitrification Values
Denitrification was not influenced by cover crops at either site, at any sampling date (data not shown). Seasonal variations were noted, and values ranged from lows in October of 0 to 21 g ha^-1 N d^-1 to highs in June of 8 to 95 g ha^-1 N d^-1.

	Discussion

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results Discussion REFERENCES

 
Cover crops had the capacity to deplete soil NO^-₃–N in the fall relative to the control treatment. Gravitational soil solution NO^-₃–N concentrations are within the range found by Brandi-Dohrn et al. (1997). With cover crops, values of soil solution NO^-₃–N did not always fall below 10 mg L^-1. However, the improvement in soil NO^-₃–N levels with cover crops was significant. Cover crop plots increased in NO^-₃–N through net mineralization and nitrification during this period, but this higher soil mineral N value in the spring was not reflected in higher corn yields. Values are within the range of equivalent N fertilizer found by Ebelhar et al. (1984), Hargrove (1986), McVay et al. (1989), Holderbaum et al. (1990), and Clark et al. (1995). Cover crop contribution to subsequent sweet corn was found to a limited extent in grain N uptake. This supports the Hargrove (1986) observation that grain N content seemed to be a better parameter to estimate cover crop contribution to subsequent corn. This lack of yield response indicated that 40 to 60 kg ha^-1 of NO₃–N in plots with cover crops was sufficient N for sweet corn growth. However, in situations where the background N levels are low, yield increases with cover crops could be found (Holderbaum et al., 1990). In general, cover crops had no negative effect on sweet corn growth and yield.

Both methods for estimating NO^-₃–N leaching losses showed similar overall trends between soils. Estimated losses of NO^-₃–N were higher at the St. Bernard site than Ste. Rosalie site using either method. This could be due to reduced movement of NO^-₃–N over the winter due to a higher clay content in Ste. Rosalie soil than in St. Bernard soil, or due to rapid surface water movement down fissures in the high-clay Ste. Rosalie soil, reducing N levels in the leaching water.

Differences in estimates of NO^-₃–N loss between methods varied with the year. In the winter of 1994–1995, at the Ste. Rosalie site, losses of NO^-₃–N calculated by each method were similar for control plots, but at St. Bernard, soil losses estimated using the soil gravitational solution method were higher than when using the sequential soil core sample method. In both soils, losses during winter 1995–1996 calculated from soil solution were less than those obtained from the sequential soil core sample method. This difference could be due to rapid surface preferential flow of water through soil macropores or fissures diluting gravitational soil solution NO^-₃–N levels (Francis et al., 1994). Amount and distribution of over-winter precipitation was similar for both years, at 396 and 386 mm (November to March, inclusive), and was probably not a major cause of difference between years. Francis et al. (1994) stated that the sequential soil core sample method could overestimate losses if denitrification was significant during the fall to spring period. However, our denitrification rates were low in this period. Thus, denitrification is not considered to have been a significant component of the N cycle in the fall to spring time of the year.

In 1994, species differences were not pronounced, due to low dry matter production. In 1995, when the cover crop dry matter yields were higher, species effects were large. Barley, forage radish, and canola generally produced the highest shoot and root dry matter at both sites.

Root uptake N tended to parallel shoot N uptake but was only 10 to 20% of the total N uptake. Our results support previous observations of percentage of N contained in the cover crop shoots. Jensen et al. (1944) and Mitchell and Teel (1977) reported that more than 80% of the N in several forage species was contained in the shoots. Touchton et al. (1982) concluded that no more than 30% of N can be expected in the root system.

Losses of NH⁺₄–N, P, and K were not affected by cover crop, due to their low mobility in soils or retention on cation exchange complexes. With adequate cation exchange capacity in these soils, cations such as NH⁺₄–N and K⁺ would remain largely adsorbed. Phosphorus was largely immobile, due to fixation in the soils.

The highest denitrification values occurred during growth of the sweet corn, because residual N levels in the soil were high (De Klein and van Logtestijin, 1994) and temperature was high (Mancino et al., 1988) compared with the period of cover crop growth, when the temperature was low. The hypothesis that denitrification would be increased with cover crop (Aulakh et al., 1983) use was not supported, and cover crops following sweet corn had no apparent effect on denitrification.

Criteria for cover crop selection should include ease of establishment, effective absorption of excess fertilizer N, reduction of nutrient loss by leaching, and subsequent release of N for growth of a following crop. Under these criteria, establishment was most successful with forage radish, barley, and canola. In contrast, legumes and ryegrass resulted in disappointing stands and their effectiveness was limited under the short-term period of growth used in the experiment. Cover crops achieved the objectives of reducing potential fall leaching and ensuring adequate soil N levels the following spring.Jensen Frith 1944

	NOTES

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results Discussion REFERENCES

 
Funded by Auxiliary Canada–Quebec Entente, Contract Research Program.

Received for publication June 11, 1998.

	REFERENCES

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results Discussion REFERENCES

 

• Aulakh M.S., Rennie D.A., Paul E.A. Field studies of gaseous N losses under continuous wheat versus a wheat fallow rotation. Plant Soil 1983;75:15-27.
• Bock B.R. Efficient use of N in cropping systems. In: Hauck R.D., ed. Nitrogen in crop production. Madison, WI: ASA, 1984:273-294.
• Brandi-Dohrn F.M., Dick R.P., Hess M., Kauffman S.M., Hemphill D.D., Selker J.S. Nitrate leaching under a cereal rye cover crops. J. Environ. Qual. 1997;26:181-188.[Abstract/Free Full Text]
• Clark A.J., Decker A.M., Meisinger J.J., Mulford F.R., McIntosh M.S. Hairy vetch kill date effects on soil water and corn production. Agron. J. 1995;87:579-585.[Abstract/Free Full Text]
• Davidson E.A. Sources of nitric oxide and nitrous oxide following wetting of dry soil. Soil Sci. Soc. Am. J. 1992;56:95-102.[Abstract/Free Full Text]
• De Klein C.A., van Logtestijn R.S. Denitrification in the top soil of managed grassland in the Netherlands in relation to soil and fertilizer level. Plant Soil 1994;163:33-44.
• Ebelhar S.A., Frye W.W., Blevins R.L. Nitrogen from legume cover crops for no-till corn. Agron. J. 1984;76:51-55.[Abstract/Free Full Text]
• Francis G.S., Haynes R.J., Williams P.H. Nitrogen mineralization, nitrate leaching and crop growth after ploughing-in leguminous and non-leguminous grain crop residues. J. Agric. Sci. (Camb.) 1994;123:81-87.
• Hargrove W.L. Winter legumes as a nitrogen sources for no-tillage grain sorghum. Agron. J. 1986;78:70-74.[Abstract/Free Full Text]
• Holderbaum J.F., Decker A.M., Meisinger J.J., Mulford F.R., Vough L.R. Fall-seeded legume cover crops for no-tillage corn in the humid east. Agron. J. 1990;82:117-127.[Abstract/Free Full Text]
• Jensen H.L., Frith D. Production of nitrate from root and root nodules of lucerne and subterranean clover. Proc. Linn. Soc. N.S.W. 1944;69:210-214.
• Karlen D.L., Doran J.W. Cover crop management effects on soybean and corn growth and nitrogen dynamics in an on-farm study. Am. J. Altern. Agric. 1991;6(2):71-82.
• Keeney D.R., Nelson D.W. Nitrogen: Inorganic forms. In: Page et al A.L., ed. Methods of soil analysis. Madison, WI: ASA and SSSA, 1982:643-693 Part 2. 2nd ed. Agron. Monogr. 9..
• Mancino C.F., Torello W., Wehner D.J. Denitrification losses from Kentucky bluegrass sod. Agron. J. 1988;80:148-153.[Abstract/Free Full Text]
• McKeague J.A. Soil sampling and analysis. Ottawa, ON: Soil Res. Inst, 1976.
• McVay K.A., Radcliffe D.E., Hargrove W.H. Winter legume effects on soil properties and nitrogen fertilizer requirements. Soil Sci. Soc. Am. J. 1989;53:1856-1862.[Abstract/Free Full Text]
• Miller, M.H., T.J. Vyn, G.A. Stewart, J.D. Lauzon, and R. Raudra. 1992. The use of cover crops for nutrient conservation. p. 163. Rapport final PAMPA, No. 42, Ontario, Canada.
• Mitchell W.H., Teel M.R. Winter-annual cover crops for no-tillage corn production. Agron. J. 1977;69:569-573.[Abstract/Free Full Text]
• Nelson D.W., Sommers L.E. Total carbon, and organic matter. In: Page A.L., ed. Methods of soil analysis. Madison, WI: ASA and SSSA, 1982:539-577 Part 2. 2nd ed. Agron. Monogr. 9..
• Rolston D.E. Nitrous oxide and nitrogen gas production in fertilizer loss. In: Delwiche C.C., ed. Denitrification, nitrification, and atmospheric nitrous oxide. New York: John Wiley & Sons, 1981:129-149.
• Thomas R.L., Sheard R.W., Moyer J.R. Comparison of conventional and automated procedure for nitrogen, phosphorus, and potassium analysis of plant material using a single digestion. Agron. J. 1967;59:240-243.[Abstract/Free Full Text]
• Touchton J.T., Gardner W.A., Hargrove W.L., Duncan R.R. Reseeding crimson clover as a N source for no-tillage grain sorghum production. Agron. J. 1982;74:283-286.[Abstract/Free Full Text]
• Tran, T.S., and R.R. Simard. 1993. Mehlich III extractable elements. p. 43–49. In Soil sampling and methods of analysis. Can. Soc. Soil Sci., Lewis Publ., Boca Raton, FL.
• Zhang T.Q., MacKenzie A.F. Phosphorus in zero tension soil solution as influenced by long-term fertilization of corn (Zea mays L.). Can. J. Soil Sci. 1997;77:685-691.

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