University of Arkansas, Fayetteville Division of Agriculture


Ecosystem productivity


Agricultural land use affects soil physical properties, such as bulk density, water content, organic matter content, and soil structure; all of which in turn affect ecosystem productivity. The objective of this study was to evaluate the effects of: 1) time since aboveground biomass has been removed by haying (i.e., 0 vs. 23 years), and 2) land use (i.e., undisturbed tallgrass prairie vs. cultivated agriculture) on water-retention characteristics in a silt-loam soil of the Grand Prairie region of eastern Arkansas. Soil samples were collected from the 0- to 10-cm depth and were wetted with varying amounts of distillated water to create a range of soil water contents. After overnight equilibration, the water potential of the soil was measured using a dewpoint potentiameter. The relationship between water potential and water content for the prairie and the agricultural soils was modeled using the equation Y=aX-b, where Y was the water potential and X was the gravimetric soil water content and the coefficients a and b were determined from fitting the data. The modeled a and b coefficients did not differ significantly by land use of soil series evaluated. The results of this study do not support the original hypothesis that water-retention characteristics in cultivated agricultural soils differ significantly from that of undisturbed, tallgrass prairie soil.