Harvest Management of a Crimson Clover Cover Crop For No‐Tillage Corn Production

Abstract

Legume cover crops are valuable N sources for no‐tillage corn (Zea mays L.). However, little research has been done in assessing the management options for legume cover crops. Field studies were conducted on a Coastal Plain Matapeake silt loam soil (fine‐silt, mixed, mesic Typic Hapludult) from 1983 through 1986 to determine the effects of various harvest management schedules on total N contribution of legume cover crops, subsequent corn grain and silage yields, and total forage (combined cover crop and corn herbage) production. A crimson clover (Trifolium incarnatum L.) cover crop was subjected to no harvest; spring silage harvest with clippings removed (spring silage); and simulated pasture harvests with clippings from multiple harvests removed (pasture removed) or returned (pasture returned). A no‐cover control treatment was also included. No‐tillage corn was grown in the cover crop residues and two fertilizer N (FN) rates (0 and 90 kg ha−1) were applied in a split‐block design to each harvest management treatment. Averaged over 3 yr, multiple harvests of the cover crop vs. a spring silage harvest resulted in lower cover crop herbage yields (3.0 vs. 4.7 Mg ha−1) and total N content (114 vs. 146 kg N ha−1) for the multiple harvests. Corn grain and silage yields and corn N uptake were consistently higher following crimson clover cover than for no cover, regardless of harvest management, and were generally higher when the cover was left in place than following removal of the cover. There were FN responses regardless of harvest management treatment. The reduction in corn silage yield when the cover crop was harvested and removed was less than the cover crop herbage dry matter yield, resulting in greater total forage production when the cover crop was harvested as forage. Results suggest that harvest management options of a crimson clover cover crop offer flexibility in either optimizing subsequent corn grain yields or total forage production for no‐tillage cropping systems and provide control over how cover crop N is utilized in the overall cropping system.

Cut and Post‐Cut Herbage Management Affects Berseem Clover Seed Yield

“…Compared to the removal of berseem herbage, its return to the soil/crop produced an increase in the yields of wheat straw and grain in the subsequent growing season, particularly when the herbage was chopped. Holderbaum et al (1990) found that in corn ( Zea mays L.) following a crimson clover cover crop both grain and silage yields were higher when clippings were returned rather than removed. Chopping the herbage resulted in a small but significant increase in wheat yield compared to returning it unchopped; according to several authors (Guérif, 1979; Swift et al, 1979; Chesson, 1997; Fruit et al, 1998), reducing the size of the mulching material may increase the decomposition of biochemical components and enhance the exchange of nutrients with the surrounding soil.…”

Influence of Winter Cover Crop and Residue Management on Soil Nitrogen Availability and Corn

“…The effectiveness of nonleguminous cover crops or mixture of leguminous and nonleguminous cover crops to reduce NO 3 –N leaching is well recognized (Brandi‐Dohrn et al, 1997; Owens, 1990). The effectiveness of various types of cover crops or combination of different cover crop species on soil N availability and the productivity of succeeding crops has been extensively evaluated (Holderbaum et al, 1990; Clark et al, 1997a; Kuo et al, 1996, Smith et al, 1987). It is quite clear from the literature that N content or C/N ratio of cover crop is a principal determinant of cover crop residue effects on soil N availability after residue incorporation into soil (Hargrove, 1986; Ranells and Wagger, 1996; Smith et al, 1987).…”

“…Removing top growth of legume or rye cover crops may leave little, if any, effects on yield of succeeding corn or sorghum [ Sorghum bicolor (L.) Moench] (Doll and Link, 1957; Raimbault et al, 1990). Even with a slight reduction in corn yield when the top growth of crimson clover ( Trifolium incarnatum L.) was removed, the reduction was more than compensated for by the harvested crimson clover (Holderbaum et al, 1990). The total biomass yield under this residue management system was still higher than the total corn silage yield with the incorporation of the clover residue into the soil.…”

Crimson Clover Management to Enhance Reseeding and No‐Till Corn Grain Production

“…was evident during the cool, wet, late winter period in 1989 and may have reduced crimson clover DM production by corn planting time. Sclerotinia rot has been reported in reseeded crimson clover stands during cool, moist, late winter and early spring periods, especially when considerable fall growth occurred (Holderbaum et al, 1990a;Myers and Wagger, 1991).…”

“…Recent studies with crimson clover as a cover crop in no-tillage systems showed corn yield responded to as much as 90 kg ha-l of fertilizer N in seasons with adequate rainfall distribution (Ebelhar et al, 1984;Fleming et al, 1981;Holderbaum et al, 1990a). However, corn grain yield following crimson clover, rye (Secale cereale L.), or hairy vetch (Vicia villosa Roth.)…”