Grouping water storage properties of Indian soils for soil water balance model applications

Soil water balance models are useful tools of agricultural and water resources planning and management. Data of water storage limits of soil profiles, field capacity (FC) and permanent wilting point (PWP), are essential for running soil water balance models. A procedure for estimating these parameters for Indian soils is presented. The values of FC and PWP for each textural class are estimated independently for alluvial, black and red soils. The estimated parameters are tested by running a soil water balance model for a case study area. The use of the model in saving irrigation water is also demonstrated. The estimated parameters of Indian soils are also compared with corresponding values of US soils. The comparisons are favourable for FC for all soil texture groups, and for PWP for coarse to medium and medium texture groups. Differences in PWP between US and Indian soils increase at finer soil textures as a result of differences in clay fraction, mineralogy, and organic matter content.