Short-term Effects of Land Leveling on Soil Physical Properties and Microbial Biomass. (S06-brye766716-oral)
Authors:
K.R. Brye* - University of Arkansas N.A. Slaton - University of Arkansas M.C. Savin - University of Arkansas R.J. Norman - University of Arkansas D.M. Miller - University of Arkansas
Abstract:
The spatial variability and distributions of soil physical and biological properties, and the relationships between them, are not well-characterized in agroecosystems that have been land leveled. The
objectives of this study were to characterize the short-term impacts of land leveling on soil physical and biological properties in a Stuttgart silt loam (Albaqultic Hapludalf) used for irrigated soybean and rice production in the Mississippi Delta region of eastern Arkansas. Bulk density, and sand and clay contents significantly increased, while silt content, and fungal and bacterial biomass significantly decreased, as a result of land leveling. However, the fungal-to-bacterial biomass ratio did not change despite the effect leveling had on the relative abundance of the fungal and bacterial biomass. Land leveling significantly changed the variance associated with soil biological properties, but the variances of soil physical properties were unaffected. The spatial distributions of soil fungal and bacterial biomass in the top 10 cm were most noticeably altered by land leveling in comparison to pre-leveling distributions.
The relationships between soil physical and biological properties also changed significantly as a result of land leveling, but the predictive ability of the relationships was surprisingly poor. These results indicate that variability in soil biological properties may play an important role in restoring productivity to precision-leveled soils.
Speaker Information: Kristofor R. Brye, University of Arkansas, University of Arkansas Department of Crop, Soil,, Fayetteville, AR 72701; Phone: 479-575-5742; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 7:55 AM-10:30 AM Presentation Start: 10:00 AM
Keywords: land leveling; physical properties; microbial biomass; soil and water conservation
