As water demand is increasing and the world food problem is becoming more pronounced، world efforts are forwarded towards the optimal usage of water resources، specially in regions where water is scare or irrigation is very costly. Inadequate irrigation is considered one of the methods that increase water usage efficiency and the application of optimization methods is essential in order to increase agriculture production.
A mathematical model was developed for optimal allocation of irrigation water under full and inadequate irrigation. The model determines the optimal seasonal allocation of irrigation water between crops. The output of the model are the area and water allocated for each crop under limited and full irrigation، the effects of various management options، as changing the plan of agriculture، type of production function، and value of irrigation water، were studied. The model was run for many percentages of full irrigation ranging from 10% to 100%. The model is considered a good approach for deciding on area and amount of irrigation water which achieves optimal values in irrigation planning projects under limited water resources.
Keywords: irrigation optimization, nonlinear programming, limited irrigation water, water allocation for different crops.