Evaluation on Crop Water Demand and Supply in Plentiful and Coarse Sandy Area in Loess Plateau
The water demand and supply condition of main crops, such as spring wheat, winter wheat, spring maize, summer maize, and cotton, and grassland in the growth stage in the plentiful and coarse sandy area in the Loess Plateau is evaluated with the potential evapotranspiration, actual crop evapotranspiration, water profit and loss, and water correction coefficient. It indicates that the water demand decreases by winter wheat, cotton, spring maize, spring wheat, and summer maize. And the water correction coefficient decreases by spring maize, summer maize, cotton, spring wheat, and winter wheat. Whereas the water demand in the grassland is 350-450mm, and the water correction coefficient is over 0 95, which show that the confliction of water demand and supply in the grassland is lower. Returning farmland to grassland in the region is an effective measure that can ameliorate the water resource shortage and improve the ecological environment.