SW--Soil and Water: Optimal Scheduling of a Micro-irrigation System under Deficit Irrigation

The time schedule of micro-irrigation for a given irrigation interval can be expressed by an irrigation scheduling parameter which is defined as the ratio of the amount required and the amount applied. Different values of the scheduling parameter can provide over-irrigation as well as deficit irrigation in different areas of the field. A well-designed micro-irrigation system cannot reach its full potential and the goal of irrigation if the decision on irrigation scheduling is not properly taken. An economic analysis was carried out on the basis of the linear models of irrigation water distribution and crop response to deficit irrigation for all values of the scheduling parameter. An optimal irrigation schedule was determined to achieve an optimal return. A case study was presented to compare the optimal irrigation schedule with the conventional irrigation schedule in which the whole field is irrigated to the required amount. The optimum irrigation schedule can achieve optimum returns and also save water at the same time.