Andre Biscaro1, Francisco J. Arriaga2, Kipling Balkcom2, Joey Shaw1, Edzard Van Santen1, Jason S. Bergtold2, and Randy L. Raper2. (1) Auburn University, Auburn University, 411 S. Donahue Dr., Auburn University, AL 36832, (2) USDA-ARS, 411 S Donahue Dr, Auburn, AL 36832
Crop production has become more competitive every year, and improving recommendation and implementation of site-specific crop management can help farmers to achieve input optimization and consequent savings. The use of precision agriculture techniques is completely dependent on understanding the spatial variability of soil physical properties. In order to assess management practices and landscape variability effects on soil physical properties, infiltration, aggregate stability and total carbon were measured in a 9-ha field in the central Alabama Coastal Plain. Based on the local soil properties, the field was separated into three zones - summit, backslope and accumulation. Four tillage systems treatments - conventional system with (CTM) or without (CT) dairy manure, and conservation system with (NTM) or without (NT) dairy manure - and corn-cotton rotation have been established in the study area since 2001. Overall, the three measurements herein assessed were lower on CT. The carbon content was significantly higher (p-value ≤ 0.001) on the treatments with manure, where CTM was 62% greater than CT, and NTM was 39% greater than NT. As expected, infiltration was higher on the summit (0.004 cm s-1), followed by backslope and accumulation zones (0.0024 and 0.002 cm s-1, respectively). No significant difference (p-value = 0.69 and 0.39, respectively) was found for aggregate stability and carbon among the zones. So far, conservation tillage has improved infiltration, and manure has increased the soil carbon content of the soil.