THREE METHODS FOR CALCULATING SOIL WATER DYNAMICS

R. A. Poluektov, I. V. Oparina, and V. V. Terleev

Three versions of a model designed for calculating the dynamics of the water regime of soil under agricultural crops in real time are described. The one-layer version of the model is based on a simple balance scheme that enables the calculation of the soil water storage in the top 1-m soil layer. This version can be used both separately or being incorporated into the Agrotool simulation system modeling the production process of plants. Two other versions are incorporated into the Agrotool system. The three-layer version is based on an explicit difference calculation scheme. Its characteristic feature is an estimation of actual values of transpiration and physical evaporation using an original method more accurate than the previously developed ones. The third version of the model uses the Crank—Nicholson scheme with iterations. All the three model versions are maximally intended for the use of standard agrometeorological information.