Yield losses of soybean and maize by competition with interseeded cover crops and weeds in organic-based cropping systems Export

@article{FIELD_CROP_RES_V113pp342-351, abstract = {Weed management is a major issue in organic farming systems. Although interseeding cover crops is one alternative to herbicides, cover crops often suppress not only weeds but also main crops. Therefore, using cover crops for weed control without adverse effects on main crop growth is important. To verify the effect of cover crops on competition between main crops, cover crops and weeds in a snowy-cold region, main crops soybean ( Glycine max Merr.) in 2005 and maize ( Zea mays L.) in 2006 were grown with cover crops winter rye ( Secale cereale L.) and hairy vetch ( Vicia villosa Roth), respectively. The cover crops were sown on three sowing dates: before main crop planting (Pre-MC), on the same date of main crop planting (Syn-MC) and after main crop planting (Post-MC). A plot without cover crops (Sole-MC) was used as a control. The dry weight (DW), vegetation cover ratio (VCR), vertical community structure and chlorophyll content were measured to estimate the competition between main crops, cover crops and weeds. Weed DW was suppressed significantly by sowing cover crops in both soybean and maize. This weed suppression was associated with the increase of VCR of main crops plus cover crops at the early growth stage of main crops. Soil seed banks of dominant weed also became lower by sowing cover crops, implying the importance of proper weed management for suppressing weeds successively. In addition, the sowing dates of cover crops had large effects on main crops DW especially in maize, i.e., it was significantly lower in Pre-MC and Syn-MC than in Post-MC. Although the cover crop height was markedly shorter than the main crop height, the chlorophyll content of the main crops was significantly lower when cover crops were sown earlier. These results suggest that the growth inhibition of main crops by cover crops was partly caused by competition for nutrients between main crops and cover crops, and this growth inhibition was alleviated when cover crops were sown after the establishment of main crops. Consequently, soybean yield was the highest in Post-MC and decreased by 29\%, 18\% and 7\% in Sole-MC, Pre-MC and Syn-MC, respectively, and maize yield was also the highest in Post-MC and decreased by 68\%, 100\% and 24\% in Sole-MC, Pre-MC and Syn-MC, respectively. It was concluded that weeds could be controlled effectively by sowing cover crops after planting main crops in organic farming systems in a snowy-cold region.}, author = {Uchino, H. and Iwama, K. and Jitsuyama, Y. and Yudate, T. and Nakamura, S.}, citeulike-article-id = {5310418}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.fcr.2009.06.013}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/S037842900900166X}, day = {04}, doi = {10.1016/j.fcr.2009.06.013}, issn = {03784290}, journal = {Field Crops Research}, keywords = {agriculture, cover\_crop, intercropping, maize, organic\_agriculture, rye, sowing, soybean, time, vetch, weed}, month = {September}, number = {3}, pages = {342--351}, posted-at = {2009-11-04 11:14:38}, priority = {0}, title = {Yield losses of soybean and maize by competition with interseeded cover crops and weeds in organic-based cropping systems}, url = {http://dx.doi.org/10.1016/j.fcr.2009.06.013}, volume = {113}, year = {2009} }

TY - JOUR ID - FIELD_CROP_RES_V113pp342-351 L3 - citeulike-article-id:5310418 N2 - Weed management is a major issue in organic farming systems. Although interseeding cover crops is one alternative to herbicides, cover crops often suppress not only weeds but also main crops. Therefore, using cover crops for weed control without adverse effects on main crop growth is important. To verify the effect of cover crops on competition between main crops, cover crops and weeds in a snowy-cold region, main crops soybean ( Glycine max Merr.) in 2005 and maize ( Zea mays L.) in 2006 were grown with cover crops winter rye ( Secale cereale L.) and hairy vetch ( Vicia villosa Roth), respectively. The cover crops were sown on three sowing dates: before main crop planting (Pre-MC), on the same date of main crop planting (Syn-MC) and after main crop planting (Post-MC). A plot without cover crops (Sole-MC) was used as a control. The dry weight (DW), vegetation cover ratio (VCR), vertical community structure and chlorophyll content were measured to estimate the competition between main crops, cover crops and weeds. Weed DW was suppressed significantly by sowing cover crops in both soybean and maize. This weed suppression was associated with the increase of VCR of main crops plus cover crops at the early growth stage of main crops. Soil seed banks of dominant weed also became lower by sowing cover crops, implying the importance of proper weed management for suppressing weeds successively. In addition, the sowing dates of cover crops had large effects on main crops DW especially in maize, i.e., it was significantly lower in Pre-MC and Syn-MC than in Post-MC. Although the cover crop height was markedly shorter than the main crop height, the chlorophyll content of the main crops was significantly lower when cover crops were sown earlier. These results suggest that the growth inhibition of main crops by cover crops was partly caused by competition for nutrients between main crops and cover crops, and this growth inhibition was alleviated when cover crops were sown after the establishment of main crops. Consequently, soybean yield was the highest in Post-MC and decreased by 29%, 18% and 7% in Sole-MC, Pre-MC and Syn-MC, respectively, and maize yield was also the highest in Post-MC and decreased by 68%, 100% and 24% in Sole-MC, Pre-MC and Syn-MC, respectively. It was concluded that weeds could be controlled effectively by sowing cover crops after planting main crops in organic farming systems in a snowy-cold region. IS - 3 JF - Field Crops Research SN - 03784290 EP - 351 TI - Yield losses of soybean and maize by competition with interseeded cover crops and weeds in organic-based cropping systems VL - 113 SP - 342 KW - agriculture KW - cover_crop KW - intercropping KW - maize KW - organic_agriculture KW - rye KW - sowing KW - soybean KW - time KW - vetch KW - weed AU - Uchino, H AU - Iwama, K AU - Jitsuyama, Y AU - Yudate, T AU - Nakamura, S PY - 2009/09/04/ UR - http://dx.doi.org/10.1016/j.fcr.2009.06.013 ER -