INTEGRATING CATTLE IN A SOUTHERN PIEDMONT CONSERVATION TILLAGE COTTON-COVER CROP SYSTEM Harry H. Schomberg, D. Wayne Reeves, Dwight S. Fisher, Randy L. Raper, Dinku M. Endale, and Michael B. Jenkins. USDA-ARS J. Phil Campbell, Sr., Natural Resource Conservation Center in Watkinsville, GA harry.schomberg@ars.usda.gov INTRODUCTION Winter cover crops are often perceived as costly because there are no direct returns from selling the cover crop (Snapp et al., 2005). Additional negative concerns are expressed due to the potential for cover crop induced water stress early in the growth of the main cash crop. Cover crop conservation benefits have been documented for all major crops and growing regions of the US (Dabney, et al., 2001). Beyond the soil conservation benefits, cover crops have been shown to improve water availability by contributing to improvements in soil physical properties that directly influence water infiltration and reduce runoff (Touchton, et al., 1984; Bruce et al., 1995). Payments from government incentive programs, like the Conservation Security Program, can help offset the cost of cover crops (up to $8 acre -1 ) (Causarano et al., 2005). Another option for offsetting cover crop costs and increasing farm revenue is grazing of winter cover crops by cattle (Bos taurus L.). Grazing stocker cattle in a cotton-peanut rotation in south Alabama produced $157 gross return and $75 net return per acre from cattle (Siri-Prieto et al., 2003). Grazing cover crops may reduce soil productivity due to hoof induced soil compaction during the grazing period (Miller et al., 1997). Cotton yields were reduced an average of 14% in two out of three years on silt loam soil in North Alabama where cover crops were grazed (Mullins and Burmester, 1997). The degree of soil compaction from grazing is influenced by a number of factors (soil texture, soil water content, grazing intensity, vegetation type and climate regime; Taboada and Lavado, 1988). Siri-Prieto et al. (2003) found that paratill or in-row subsoiling was required to alleviate grazing induced compaction and maximize cotton and peanut yields in south Alabama. In the Southern Piedmont, depth to the Bt layer influences profile soil water content and in turn can influence the degree of compaction from grazing. Depth to the Bt is spatially distributed with erosion class being a surrogate indicator but at a very rough scale (Endale et al., 2006). Other factors influencing soil response to cattle may also be spatially variable but need to be quantified before management strategies can be developed to both reduce compaction initially and apply ameliorative remedies on a spatial basis. By identifying important spatially variable factors, the potential exists to combine new technologies for evaluating spatial variability with GPS technology and in cab GIS maps to identify management zones requiring deep tillage. Performing deep tillage only on areas with a high probability of compaction would therefore reduce producer costs. Our objectives were to evaluate on a spatial scale the impact of cattle grazing winter annual small grains on (1) cotton and (2) animal production and (3) soil compaction. We measured a number of spatially distributed soil and plant properties to identify those that might easily be combined to define management zones for applying remedies for soil compaction.