AGRONOMY AND SOILS Cotton Production in Rotation with Summer Legumes

Sunn hemp (Crotolaria juncea) is a fast grow-ing tropical legume that can accumulate large amounts of biomass and N in a relatively short period of time during the summer in the south-east US. This study was conducted to evaluate the potential of using this legume as an N source for cotton (Gossypium hirsutum L.). A field study was conducted in 2004-2005 and 2006-2007. Treatments were summer legume [sunn hemp, cowpeas (Vigna unguiculata), and summer fallow] and fertilizer N rate applied to cotton (0, 45, 90, and 135 kg N ha-1). The summer legumes were planted in mid-summer (July) and cotton was planted the following spring (May). Sunn hemp