Grazing Winter Cover Crops in a Cotton-Cover Crop Conservation Tillage System.

Grazing of winter annual cover crops with cattle offers a way to offset costs and increase farm revenue in conservation tillage systems. Cattle may also create problems due to treading of surfaces and reductions in surface residues needed to affect soil erosion.  Maximizing returns may require application of precision agricultural methods to manage spatially variable effects from cattle grazing.  We are evaluating grazing effects on conservation tillage cotton grown on Cecil soil (fine, kaolinitic, thermic, Typic Kanhapludult) at the USDA-ARS Research Center, Watkinsville, GA using four long-term conservation systems watersheds instrumented to measure runoff and sediment loss.  In 2006 and 2007, cereal rye (Secale cereale L.) provided approximately 4.5 Mg ha^-1 of forage, enough for 3.5 Angus heifers (Bos Taurus) ha^-1 between February 1^st and April 15^th.   Seed cotton yields ranged from 2.4 Mg ha^-1 to 3.3 Mg ha^-1 in 2006 a year with good rain and only 15 to 20% of this amount in 2007 a year of sever drought.  No differences in yield were detected between grazed and ungrazed fields for either year.  Return on grazing was similar for both years while cotton returns were more variable. These results indicate grazing cover crops may be an important economic consideration for cotton producers in the Southern Piedmont because of the potential to increase revenues from grazing without reducing cotton yields.