Simulation the effects of water deficit irrigation on wheat and corn yield using the Budget model (study on Bilasuvar plain)

Correct and convenient management of water resources by preserving the sources in regional and national scales is an inevitable need. Models are the best methods to select most efficient irrigation method lead to high yield response. In this simulation effects of water deficit irrigation in Bilasuvar plain on the north-east of Ardabil province has been simulated on wheat and corn crops using Budget soil and water balance model. By choosing the product, minimum and seasonal methods with different time steps and also setting the relative evapotranspiration or relative evaporation model has been calibrated for the observation year (2004-2014) and amount of yield was estimated. Result of the statistical analysis shows that choosing the product method with 10 day time periods provides the best simulation using relative evapotranspiration with amounts in an R^2 of 0.98, an RMSE of 78% and an EF of 0.83 that between observed and simulated data of wheat and amount in an R^2 of 0.87, an RMSE of 7.4% and an EF of 0.83 of corn. Later water consumption graphs, performance for each statistic period (2004-2014) under different irrigation strategies have been drawn for both crops. Results demonstrates significant impact of rainfall amount, water preservation capacity, water consumption management and water tension in both crops during the middle stage of its growth compared to the stages of growth including first and final stage. This important fact must be considered for planning the water deficit irrigation schedule.