IRRIGATIONS NINTH CONGRESS

Irrigation scheduling is rapidly gaining acceptance as a valuable tool for developing an on-farm water management program. Irrigation scheduling 'develops the optimum timing and amounts of irrigation applications and pro-vides the ability to manage the soil-moisture reservoir. Improving the timing and amounts of irrigation applied will reduce the adverse environ-mental effects of irrigated agriculture. Improved management of the soil-moisture reservoir directly benefits the irrigator economically. A com-puter is used to maintain a daily water budget, give the current status of the soil-moisture reservoir, and predict evapotranspiration for the next 14 days. Data required are basic soil-moisture properties, estimated rate of crop development, and daily climatic data. By applying these parameters as they individually and comprehensively relate to an irrigation project and the local. cultural practices, an optimum irrigation schedule can be developed. This schedule gives attention to the many decision considerations that an irrigator needs to make in his day-to-clay operation. Irrigation scheduling is the "grass roots " level of water management, and the initial step of any comprehensive land and water management concept related to irrigated agriculture. Programme d'irrigation pour un emploi optimum