Legume Cover Crop Contributions to No‐Tillage Corn Production

Abstract

Winter cover crops can supply N to the next crop, reduce erosion and N leaching, and conserve or deplete soil moisture. To identify optimum corn fertilizer nitrogen (FN) rates following cover crops, we evaluated hairy vetch (Vf: Jlicia villosa Roth), Austrian winter pea [PE: Pisum sativum L. subsp. sativum var. arvense (L.) Poir.], crimson clover (CR: Trifolium incartUllum L.), and wheat (WH: Triticum aes· ti~·um L.) winter cover crops in the U.S. Coastal Plain and Piedmont for no-tillage corn (Zea mays L.) at four FN rates (topdressed NH 4 N0 3 ) onr 4 yr. Parameters evaluated included cover crop yield and N content, corn N uptake, and corn grain yield. On the Coastal Plain, Vf, PE, CR, and WH topgrowth averaged 205, 180, 170, and 40 kg N ha-•, respectively, and ~40% less for the Piedmont. With no FN, grain yields were generally greater after legumes than after no cover crop, and lowest after WH, with the best yields after legumes with 90 to 135 kg FN ha-•. Synergistic responses occurred when FN was ap· plied after legumes. Non·N-Iimited grain yield increases averaged 2 Mg ha-• (Coastal Plain) and 0.5 Mg ha-• (Piedmont), and were not directly related to cover crop N. With no cover crop, FN needed for maximum yield averaged 80 kg ha -• (Piedmont) and 135 kg ha -• (Coastal Plain). After WH, FN needs increased 15 to 30 kg ha-•, but decreased 10 to 75 kg ha-• after legumes. Hairy vetch provided the most consistent increases, with average grain yield of 10.6 Mg ha-1 (Coastal Plain) and 8.2 Mg ha-1 (Piedmont), and an economic opti· mum FN rate of 127 (Coastal Plain) and 66 kg ha-• (Piedmont).

Recomendação de adubação nitrogenada para o milho no RS e SC adaptada ao uso de culturas de cobertura do solo, sob sistema plantio direto

“…Quando há predomínio de gramíneas, parte do N adicionado pelas leguminosas pode ser imediatamente imobilizado pelos microrganismos durante a decomposição dos resíduos, reduzindo a disponibilidade deste nutriente para a cultura em sucessão (Decker et al, 1987). Henrichs et al (2001), avaliando o milho cultivado em sucessão à consorciação de aveia + ervilhaca em diferentes proporções, concluíram que a proporção de 10% de gramínea + 90% da leguminosa foi a que mais favoreceu a absorção de N e a produtividade de grãos.…”

Living Mulch as a Tool to Control Weeds in Agroecosystems: A Review

“…Incorporating legume living mulches can also increase the yield of the succeeding crop (Bollero and Bullock 1994;Decker et al 1994). Leguminous living mulches have the potential to reduce dependence on fossil fuels and reduce negative environmental effects of crop production systems.…”

Nitrogen cycling, profit margins and sweet corn yield under fall cover crop systems

“…Cover crops may be more advantageous in vegetable than field crop production due to longer fallow periods in which cover crops can immobilize N. Cover crop N accumulation and N availability to succeeding crops can be affected by cover crop species, precipitation, temperature, length of growing season and soil fertility (Stute and Posner 1993;Decker et al 1994). Thus, it is imperative that research be conducted in Ontario to provide applicable cover crop recommendations to vegetable growers.…”