ESTABLISHMENT, DEVELOPMENT AND YIELD OF FORAGE LEGUMES AND GRASSES ASCOVER CROPS IN GRAIN CORN IN EASTERN CANADA

Interseeded cover crops can minimize soil erosion, increase organic ma tter and nutrient levels and the yield of subsequent crops. However, t heir performance is very sensitive to local conditions. Field experime nts were conducted at two Quebec locations in 1993 and 1994 in order t o evaluate the potential use of forage legumes and grasses as intersee ds in corn in eastern Canada. Twelve forage species were evaluated. Fa ll rye (Secale cereal L.), hairy vetch (Vicia villosa Roth), a mixture of red clover (Trifolium pratense L.) and ryegrass (Lolium multifloru m Lam), a mixture of white clover (Trifolium repens L.) and ryegrass, subterranean clover (Trifolium subterraneum L.), yellow sweet clover ( Melilotus officinalis Lam.), black medic (Medicago lupulina L.), Persi an clover (Trifolium resupinatum L.), strawberry clover (Trifolium fra giferum L.), crimson clover (Trifolium incarnatum L.), annual alfalfa (Medicago sativa L.) and berseem clover (Trifolium alexandrinum L.) we re seeded at two planting dates (10 and 20 days after corn emergence). The control treatments were: hand weeding, chemical weeding and non-w eeded. Early seeded forages established better and had higher biomass accumulation than the late seeded ones. In the presence of larger weed populations, the interseeded forages did not develop well due to comp etition with the weeds. At Macdonald crimson clover provided good soil cover while Persian clover, fall rye and alfalfa provided relatively little cover. Strawberry clover and hairy vetch did not provide early ground cover due to their late development. Forage mixtures of red or white clover and rye grass established well and achieved high populati ons at the end of the growing season. Fall rye provided good early gro und cover but senesced by the middle of the season. The better establi shment and early germination of crimson clover caused a 19 % reduction in corn grain yield in 1993. In 1994 none of the cover crops caused a reduction in corn yield.