CONSERVATION SYSTEMS RESEARCH FOR IMPROVING ENVIRONMENTAL QUALITY AND PRODUCER PROFITABILITY
Location: National Soil Dynamics Laboratory
Title: Management Practices and Landscape Variability Effects on Selected Soil Physical Properties
Submitted to: American Society of Agronomy Branch Meeting
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2006
Publication Date: February 5, 2007
Citation: Biscaro, A., Arriaga, F.J., Balkcom, K.S., Shaw, J., Bergtold, J.S. 2007. Management Practices and Landscape Variability Effects on Selected Soil Physical Properties [Abstract]. Southern Branch American Society of Agronomy Annual Meetings Abstracts. 2007 CD-ROM.
Understanding the spatial variability of soil physical properties is important for aiding in the recommendation and implementation of site-specific crop management. As a soil-forming factor, topography leads to soil differentiation because of variations in water infiltration and depth to water table. Topography is often strongly related to changes in soil physical properties. However, steep slopes may lead to soil removal and deterioration, specially if associated with conventional tillage practices. The use of conservation systems benefits soil by increasing organic carbon content and providing protective crop residue on the soil surface. In order to assess management practices and landscape variability effect on soil physical properties, infiltration, aggregate stability and total carbon were measured in a 9-ha field with a long history of conventional row cropping in the central Alabama Coastal Plain. Nine soil map units indicate significant soil landscape variability with soils ranging from poorly to well drained. Based on the local soil properties, the field was separated in three zones, Z1, Z2 and Z3, typifying summit, backslope and toeslope, respectively. 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. Infiltration and aggregate stability were higher on NT. The carbon content was significant higher (p-value=0.0005) on the treatments with manure, where CTM was 62% greater than CT, and NTM was 39% greater than NT. As expected, infiltration was found to be higher on Z1 (0.004cm.s-1), followed by Z2 and Z3 (0.0024 and 0.002cm.s-1, respectively). No significant difference (p-value=0.69) was found for aggregate stability among the zones. So far, conservation tillage has improved infiltration and aggregate stability, and manure has increased the soil carbon content.