Summer Cover Crops for Organic Production System: II.

Cropping systems when integrated with cover crops return economic and environmental benefits. Cover crops help suppress insects, disease, and weeds, conserve soil and water, enable efficient nutrient cycling and improve productivity. Summer cover crops are viable options for crop rotation is sustainable cropping systems. Despite growing interest in short-season summer annual cover crops, there is limited published research on these crops. In a study conducted at Alabama A&M University, 5 summer cover crops, sunflower (Helianthus annuum), buckwheat (Fagopyrum esculentum Moench), Sudan sorghum (Sorghum bicolor (L.), velvet bean (Mucuna pruriens L.), and iron-clay peas (Vigna unguiculata) were evaluated against a no-cover crop fallow using randomized complete block design. The sunflower with a significantly higher leaf area of 1.3 m² also intercepted a greater proportion (90%) of incoming PAR (Photosynthetically active radiation).  The biomass production by cover crops ranged from 0.85 Mg ha^-1 for velvet bean to 2.5 Mg ha^-1 for Sudan sorghum.  The weed biomass was significantly lower in iron clay peas (0.4 Mg ha^-1) than that in Sudan sorghum, buckwheat, and sunflower plots. This study showed the potential of summer cover crops for biomass production and suppression of weeds.