Summer Cover Crop Performance in the Gulf States

Six cover crops were evaluated over two years for biomass production in  the summer season at the two sites.  The species and seeding rates used included: sunnhemp (Crotalaria juncea, 44 kg^.ha^-1); southernpea (Vigna unguiculata, 44 kg^.ha^-1), buckwheat (Fagopyrum esculentum, 66 kg^.ha^-1); sesame (Sesamum indicum, 5.5 kg^.ha^-1); sesbania (Sesbania macrocarpa, 27^.5 kg.ha^-1); and a proprietary mix of 70% buckwheat and 30% southernpeas, 44 kg^.ha^-1)).  Untreated and/or certified organic seeds were broadcast and incorporated at recommended rates in June.  Plots received a single irrigation after planting, but received no fertilizer or pesticides prior to or during growth.  A 1 m2 area of crop and weed shoot mass was harvested at two timings.  The greatest total fresh (FW) and dry matter (DW)crop biomass production from harvest at Baton Rouge at 90 DAP in 2007 was sunnhemp (62.3 MT^.ha^-1 FW; 17.0 MT^.ha^-1 DW) and from sesame (51.6 MT^.ha^-1 FW; 9.5 MT^.ha^-1 DW).  Weed biomass was less than 15% of total fresh or dry biomass in these two cover crops.