RALEIGH, NCConservation tillage encompasses a range of techniques for establishing crops in the previous crop's residues, which are purposely left on the soil surface. The principal benefits of conservation tillage are improved water conservation and the reduction of soil erosion; additional benefits can include reduced fuel consumption, planting and harvesting flexibility, and reduced labor requirements. A new study published in HortScience finds promise in a common legume used as an effective crop cover for organically produced onions.
Conservation tillage promotes soil quality and fertility in accordance with organic principles, but the practice can be challenging. Success of conservation tillage in organic systems is highly influenced by factors such as crop rotation for weed and disease control and nitrogen availability. Surface residues in these systems are usually made up of unharvested crop remains or cover crops that were killed with herbicides (or, in the case of organics, by mechanical methods).
Researchers at North Carolina State University recently released the results of a 2-year experiment designed to assess the efficacy of summer annual grass (foxtail millet) and legume (cowpea) cover crops in different mixture ratios or monocultures. The researchers also analyzed rates of soybean meal as nitrogen amendment on overwintered, no-till, organically managed onion production. Foxtail millet and cowpea were compared with a bare-ground control for weed suppression and nitrogen contribution when followed by organically managed no-till bulb onion production
Cover crop treatments were grown during the summer (July through October) followed by no-till transplanted onions in the fall for overwinter production (November to May). The field experiment was managed according to the U.S. National Organic Program production standards. Cover crop treatments of cowpea and bare ground had the greatest total marketable onion yield
|Contact: Michael W. Neff|
American Society for Horticultural Science