University of Arkansas, Fayetteville Division of Agriculture


Tillage can negatively affect soil physical properties such as bulk density, organic matter content, and soil hydraulic properties, which in turn affect how plants grow. The objective of this study was to evaluate water retention characteristics of a Jay silt loam soil under cultivated agriculture and native tallgrass prairie in northwest Arkansas. Air-dry soil samples collected from 0-10 cm depth were re-wet with varying amounts of distilled water to create a range of water contents. After overnight equilibration, the water potential was measured on the re-wet soil samples using a dewpoint potentiameter. The relationship between water potential (Ψ) and water content (θv) for the cultivated agricultural and undisturbed prairie soil was modeled using the equation Ψ = aθv –b, where a and b are coefficients determined from fitting the data and represent the water retention characteristics for the soil of the two different land uses. The a and b coefficients did not differ significantly due to land use. Therefore, the results of this study did not support our hypothesis that agricultural land use significantly affects water retention characteristics. However, increasing the number of soil samples in which the water potential was measured could have sufficiently decreased the variability in the a and b coefficients so that significant differences in water retention characteristics as a result of land use could have been demonstrated.