Winter Cover Crops for Sod‐Planted Corn: Their Selection and Management 1

Winter cover crops for sod‐planted corn ( Zea mays L.) were studied in 11 location‐year field experiments in Virginia during the 1962–1966 period. Conventionally tilled corn with cover crop turnplowed and sod‐planted corn were also compared. Rye ( Secale cereale L.) was the most satisfactory because of superior winter hardiness, susceptibility to herbicidal killing, and the production of relatively large amounts of persistent mulch. Wheat ( Triticum aestivum L.) and oats ( Avena sativa L.) were comparable as mulches except at higher elevations where oats winterkilled. Barley ( Hordeum vulgare L.) was the least satisfactory winter grain tested because of resistance to herbicides. Inclusion of crimson clover ( Trifolium incarnatum L.) or hairy vetch ( Vicia villosa Roth.) in winter grain seedings slightly increased mulch forage but not corn yields. In general, highest corn yields occurred where largest amounts of cover crop mulch occurred, except for Italian ryegrass ( Lolium multiflorum Lam.). The additional mulch produced by late versus early killing of particular cover crops tended to increase corn yields, though not always significantly. Planting corn in rye stubble after removal of forage for hay or silage reduced corn yields an average of 47% in three of seven comparisons with rye left as mulch, while yields in the remaining four were comparable. Yields of sod‐planted corn in rye sod averaged 44% higher than conventionally tilled corn in 4 of 13 comparisons and were comparable in the remaining nine. More soil moisture was found under sod‐planted corn than under conventionally tilled corn, especially during the first half of the growing season. Corn yields were increased or at least maintained, in comparison to conventional tillage, by sod‐planting in rye over a wide range of soil and moisture conditions, with the added advantages of improved soil and water conservation.