Evaluating Cover Crops for Benefits, Costs and Performance within Cropping System Niches

作者：Sieglinde S. Snapp, Scott M. Swinton, Ricardo Labarta, Dale R. Mutch, J. Roy Black, Richard H. Leep, Judith Nyiraneza, Katherine O’Neil · 发表于：Agronomy Journal · 年份：2005 · DOI：10.2134/agronj2005.0322a · 被引用次数：1012 · 研究领域：Agronomic Practices and Intercropping Systems、Soil Carbon and Nitrogen Dynamics、Legume Nitrogen Fixing Symbiosis

The integration of cover crops into cropping systems brings costs and benefits, both internal and external to the farm. Benefits include promoting pest‐suppression, soil and water quality, nutrient cycling efficiency, and cash crop productivity. Costs of adopting cover crops include increased direct costs, potentially reduced income if cover crops interfere with other attractive crops, slow soil warming, difficulties in predicting N mineralization, and production expenses. Cover crop benefits tend to be higher in irrigated systems. The literature is reviewed here along with Michigan farmer experience to evaluate promising cover crop species for four niches: Northern winter (USDA Hardiness Zones 5–6), Northern summer (Zones 5–6), Southern winter (Zones 7–8), and Southern summer (Zones 7–8). Warm season C4 grasses are outstanding performers for summer niches (6–9 Mg ha−1), and rye (Secale cereale L.) is the most promising for winter niches (0.8–6 Mg ha−1) across all hardiness zones reviewed. Legume–cereal mixtures such as sudangrass (Sorghum sudanese L.)–cowpea (Vigna unguiculata L) and wheat (Triticum aestivum L.)–red clover (Trifolium pretense L.) are the most effective means to produce substantial amounts (28 Mg ha−1) of mixed quality residues. Legume covers are slow growers and expensive to establish. At the same time, legumes fix N, produce high quality but limited amounts (0.5–4 Mg ha−1) of residues, and enhance beneficial insect habitat. Brassica species produce glucosin...