Theory of field water use: basics of water flow i unsaturated soils;water uptake by plants roots;numerical approximation of flow in soil-root systems. Theory of crop production:mathematical description of growts;water and actual production;calculation of potential production. Theprogram:program for field water use, SWATR;program for crop production,CROPR;execution of SWATR; execution of CROPR.

Theory of field water use. Basics of water flow in unsaturated soils. Water uptake by plant roots. Numerical approximation of flow in soil-root systems. Theory of crop production. Mathematical description of growth. Water and actual production. Calculation of potential production. The programs. Program for field water use, SWATR. Program for crop production, CROPR. Execution of SWATR. Execution of CROPR.