Interseeded Cover Crops Research Articles

Interseeding Cover Crops into Soybean and Subsequent Corn Yields

Organic producers in the northeastern USA have difficulty establishing cover crops after soybean [Glycine Max (L.) Merr.] harvest. We interseeded species into soybean on an organic farm without livestock to identify cover crops that do not interfere with soybean harvest, provide significant ground cover, and increase subsequent corn (Zea mays L.) yields. Foenugreek (Trigonella foenum‐graceum L.), rye (Secale cereale L.), wheat (Triticum aestivum L.), strawberry clover (Trifolium fragiferum L.), and Austrian winter pea (Dolichos lignosus L.) did not meet establishment and height requirements at the time of harvest. White clover (Trifolium repens L.), red clover (Trifolium pratense L.), barrel medic (Medicago lupulina L.), alfalfa (Medicago sativa L.), annual ryegrass (Lolium multiflorum L.), and creeping red fescue (Festuca rubra L.) met these requirements and generally provided >30% ground cover. Interseeded grasses provided the most biomass (0.5–1.1 Mg ha−1) at spring plowdown. Interseeded legumes did not establish well in 1996–1997 and produced only 0.1 to 0.2 Mg ha−1 biomass in 1997. Corn yielded more following Dutch white clover (7.2 Mg ha−1) and medium red clover (6.7 Mg ha−1) than following no cover (5.7 Mg ha−1) in 1996 but yielded the same in 1997 (5.7, 6.3, and 6.2 Mg ha−1, respectively). Corn yielded less following annual ryegrass (5.3 Mg ha−1) and creeping red fescue (5.1 Mg ha−1) than following no cover in 1997. More research is needed to identify conditions that would reduce the risk of poor establishment of interseeded legumes or reduced corn yields following interseeded grasses.

Cover crops and interrow tillage for weed control in short season maize ( Zea mays)

Weed competition can cause substantial maize ( Zea mays L.) yield reductions. Interseeding maize with cover crops or a combination of interrow cultivation and interseeded cover crops are possible alternative methods of weed control. This study was conducted to examine the potential of interrow cultivation plus cover crops to reduce weed density in maize without reducing the grain yield. Field experiments were conducted in 1993 and 1994 at two sites in Québec to determine the effects of planting 12 cover crops with maize on weed control. Fall rye ( Secale cereal L.), hairy vetch ( Vicia villosa Roth), a mixture of red clover ( Trifolium pratense L.) and ryegrass ( Lolium multiflorum Lam), a mixture of white clover ( Trifolium repens L.) and ryegrass, subterranean clover ( Trifolium subterraneum L.), yellow sweet clover ( Meliotus officinalis Lam), black medic ( Medicago lupulina L.), Persian clover ( Trifolium resupinatum L.), strawberry clover ( Trifolium fragiferum L.), crimson clover ( Trifolium incarnatum L.), alfalfa ( Medicago sativa L.), and berseem clover ( Trifolium alexandrinum L.) were seeded at two planting dates, 10 and 20 days after maize emergence. Interrow cultivation was carried out weekly until forage seeding, with a final cultivation being conducted just prior to cover crop seeding. Cover crop planting date did not affect maize yields or the ability of interrow tillage plus cover crops to suppress the development of weed populations. Maize yield was less affected by the interseeded cover crops under conditions of adequate rainfall. Corn planted in fields heavily infested with weeds resulted in substantial yield reductions even when rainfall was adequate. Except for 1993 at l'Assomption interrow tillage plus cover crop treatments had consistently lower weed biomass when compared to the weedy control. Most of the weed control was due to the interrow cultivation performed prior to seeding of the cover crops. The lowest weed density occurred in the herbicide treated plots. The ability of interrow tillage plus cover crops to suppress the development of weeds was affected by the level of weed infestation, the growing conditions and location. The cover crops provide additional weed control but the interrrow tillage or some herbicide application may still be necessary.

Yield and Yield Components of Corn Interseeded with Cover Crops

AbstractThe rising costs of pesticides, soil erosion, and environmental pollution associated with corn (Zea mays L.) production have led to consideration of alternative production methods. Growing cover crops with corn could address these problems. Field experiments were conducted in 1993 and 1994 at l'Assomption and Macdonald in Quebec to determine the effects of interseeding 12 cover crops on corn yield and yield components. Fall rye (Secale cereale L.), hairy vetch (Vicia villosa Roth), a mixture of red clover (Trifolium pratense L.) and ryegrass (Lolium multiflorum Lam.), a mixture of white clover (T. repens L.) and ryegrass, subterranean clover (T. subterraneum L.), yellow sweetclover (Melilotus officinalis Lam.), black medic (Medicago lupulina L.), Persian clover (T. resupinatum L.), strawberry clover (T. fragiferum L.), crimson clover (T. incarnatum L.), alfalfa (Med. sativa L.), and berseem clover (T. alexandrinum L.) were seeded 10 and 20 d after corn emergence. The experimental design was a splitplot, randomized complete block with four replications at each site. The mainplots were the cover crop planting dates; the subplots were the 12 cover crop treatments and 3 controls (hand weeding, chemical weeding, and no weeding). Seeding the cover crops either 10 or 20 d after corn planting did not affect corn grain yield. Chlorophyll fluorescence measurements (Fv/Fm) indicated that corn plants were stressed when interseeded with crimson clover (P < 0.05). When there was competition for moisture, crimson clover was found to be too competitive with corn at the seeding rates used in this experiment. Corn yield was less affected by the interseeded cover crops under conditions of adequate rainfall. No consistent differences in corn grain yield components were found for cover crop treatments.

Integration of Cereal Cover Crops in Ridge-tillage Corn (Zea mays) Production

Field experiments evaluating 11 cereal cover crops were established at two locations in Ontario over a two-year period. Cover crops were interseeded into a ridge-tillage corn crop and evaluated in terms of biomass production and winter annual, biennial, and perennial weed species suppression. Seedling establishment and aboveground biomass production of cover crops were variable between locations and years. At both locations over two years, ‘Danko’ winter rye, ‘OAC Halton’ winter barley and ‘Rodeo’ spring barley were the most consistent cover crops in biomass production. However, cover crop residues had no significant effect on weed biomass or density due to a high degree of spatial variability present in the weed populations. Corn grain yields were not reduced by the presence of inter-seeded cover crops when compared with the bare ground control treatment.

Effect of Corn Planting Pattern on Yield, Root Extension, and Interseeded Cover Crops1

SynopsisAmong 8 corn‐planting patterns inter‐planted with cover crops, more improvement in stand establishment of cover crops per bushel reduction in corn yield occurred in corn drilled in 63‐inch rows than in hilled patterns of various dimensions.