Irrigated cropping optimization

This paper develops a nonlinear optimization model for the determination of optimal cropping patterns in irrigated agriculture. Decision variables are the cultivated area in each soil type at the farm. The objective function of the model is based on crop-water production functions, irrigation technology used, and costs and prices of the products. The model is solved using the GAMS-MINOS package for conditions existing in Chile. The model gives the optimal distribution of areas and crops, irrigation water needs, labor requirements, and total profit. Sensitivity of the optimal solution to land, labor, and water resources is examined. Results of the model show that changes in the prices of exportable products and water cost have a large impact on the cropping patterns and profit. Water availability affects the distribution and area of crops, whereas labor availability is more important for the agricultural enterprise than its wages.