Meghan Buckley-Zeimen, Gerard J. Kluitenberg, Kenneth W. Kelley, and Daniel W. Sweeney. Dept. of Agronomy, Kansas State University, 2004 Throckmorton, Manhattan, KS 66506
The Parsons soil has a sharp increase in clay content from the low twenties in the A horizon to the upper fifties in the Bt horizon. The high clay content continues to the parent material resulting in 1.5 m of dense, slowly permeable subsoil over shale residuum. This project was designed to better understand soil and water management needs of this soil. In addition to the main objective of determining a comprehensive hydrologic balance, the study also quantified the relationships between tillage and water storage as well as between stored water and crop variables. The study utilized three replicates of an ongoing project in Labette County, Kansas in which till and no-till plots have been maintained in a sorghum-soybean rotation since 1995. Both crops are grown each year in a randomized complete block design. The sorghum plots were equipped with TDR probes to measure A horizon water content and neutron access tubes for measurement of water deeper in the profile. Precipitation, evaporation, and perched water depth were measured at the field scale. Preliminarily, data indicate that the surface soil in no-till was frequently wetter during wet periods and dryer during dry periods than the tilled soil. No tillage effect was seen on water content in the Bt horizon. Over an entire growing season, cumulative differences in the hydrologic balances were minimal.
