Effects of Management Practices on Soil Hydraulic Properties for Claypan Landscapes.

Improvement in soil management practices is considered a key to sustainable farming operations. Using different management practices may lead to changes in soil hydraulic properties which may affect productivity and hydrologic processes. Perennial vegetation management which includes biomass crops as well as agroforestry buffer and grass buffer practices provides diversified productivity and ecosystem services. Thus, this study investigated the effects of perennial vegetative management systems (biomass crops, agroforestry buffers, grass buffers) relative to row crop management on soil hydraulic properties for a claypan soil in northern Missouri. The experimental watersheds for this project were located at the Greenley Memorial Research Center. Samples were collected from four treatments: no-till corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation established in 1991, agroforestry buffers established in 1997, grass buffers established in 1997, and biomass crops established in 2012. Intact soil samples were collected using a core sampler (76-mm diam. by 76-mm long). Four soil depths (0 – 40 cm in 10-cm increments) were taken with six replicates per treatment to determine saturated hydraulic conductivity (Ksat), soil water retention, bulk density, and pore size distributions. Results showed that soils under agroforestry buffers, grass buffers, and biomass crops had lower bulk density values than row crop management. Trends also showed higher saturated hydraulic conductivity for the agroforestry and grass buffers as well as biomass crops compared with the row crop area. These results indicate that conservation practices can significantly enhance soil hydraulic properties compared with row crop management, particularly in eroded claypan landscapes; these approaches have remarkable importance in addressing challenges of soil and water conservation. In addition, the results of these investigations will be useful in making improved land use management decisions for claypan landscapes.