Abstract

The purpose of this study is to predict optimal drainage design parameters for ensuring maximum crop yield under irrigated arid lands. The water management simulation model, DRAINMOD was applied to compute the effects of land drainage on soil moisture conditions in the root zone and their effect on crop yield in Bala-Koprukoy Basin in Central Anatolia Region of Turkey. Soil, crop and site parameters were obtained as inputs from field experiments. Model was run for 5 years to simulate optimum drainage design parameters (drain depth, drain spacing) while controlling soil salinity in root zone. Soil water conditions were simulated for crop rotation of corn and wheat. Yields of individual crops were predicted for each growing season. Results of the simulations were analyzed to identify alternative of subsurface drainage system that would satisfy maximum crop productions. According to the simulation results the optimum drain depth were found to be 1.2 m and drain spacing were 160 m for the multiple croppingsystem in study area.

Key words: DRAINMOD, drainage, drain space, drain depth, wheat, corn.