In-Situ Soil Water Retention Curves of a Highly Weathered Soil Under Different Land Uses.

The relationship between soil moisture content and its energy status is represented by the soil water retention curve. The soil water retention curve is a key tool for characterizing and understanding many basic soil hydrologic relationships. In addition, the soil water retention curve is a necessity for modeling of water flow and transport processes in soil. The ability of the soil to retain water is affected by factors such soil texture, soil structure, and organic matter. These factors are influenced by vegetation and human activities such as tillage. The objective of this study is to measure and examine in-situ soil water retention curves of a highly weathered soil under different land uses. Soil water retention curves will be developed from co-located measurements of soil water content and soil matric potential at five and ten centimeters below the soil surface for the different land uses. In-situ soil water retention curves obtained under the different land uses will be compared to soil water retention curves estimated from existing pedotransfer functions. Measurement results and the accuracy of the pedotransfer functions will be reported.