HYDROLOGIC AND ENVIRONMENTAL IMPACTS OF CONSERVATION PRACTICES IN OKLAHOMA AGRICULTURAL WATERSHEDS
Location: Great Plains Agroclimate and Natural Resources Research Unit
Title: Impact of conservationpractices on soil quality indicators: case study in the Fort Cobb Reservoir watershed, Oklahoma
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 9, 2011
Publication Date: August 17, 2011
Citation: Steiner, J.L., Starks, P.J., Moriasi, D.N., Stott, D.E., Zobeck, T.M., Karlen, D.L. 2011. Impact of conservation practices on soil quality indicators: case study in the Fort Cobb Reservoir watershed, Oklahoma [abstract]. ASA-CSSA-SSSA Annual Meeting, Fundamental for Life: Soil, Crop, & Environmental Sciences, Oct. 16-19, 2011, San Antonio, Texas. Available: http://a-c-s.confex.com/crops/2011am/webprogram/Paper64797.html.
Interpretive Summary: Abstract Only.
While there has been controversy amongst researchers about the concepts and terminology of soil quality, there is agreement that management has critical effects on soils and that soils can either move toward or away from a condition that is favorable for the defined use of that soil. Within watersheds, soil condition, along with storm characteristics, controls the basic hydrologic process of infiltration, retention, and runoff of precipitation. In addition, soil condition controls the ability of soils to retain, bind, and transmit solutes and contaminants that flow with water. Many conservation practices (CPs), by explicit design or otherwise, impact soil condition. Four contrasting management systems were evaluated in the Fort Cobb Reservoir watershed in southwestern Oklahoma: conventionally tilled wheat, no-till wheat, perennial grass converted from cropland (e.g., peanut conversion to bermudagrass), and native grass land. Each of the four management systems were monitored on contrasting soil types, with 10 replications (fields) for each management/soil combination. Soil quality indicators measured include field water content, microbial biomass carbon, water stable aggregation, potential mineralizable N, electrical conductivity, pH, soil test P and K, and total organic C and N, bulk density, porosity, soil volume, and water filled pore space. Changes in soil indicators will be used as metrics to classify soil quality as improved, stable, or degraded by applying factor analysis. The soil management assessment framework (SMAF) will be used to assess soil function (e.g., nutrient cycling, water relations, filtering and buffering, etc.) for selected combinations of soil and land management practices in the Ft. Cobb watershed.