Irrigation Techniques and Evaluations

The primary motivation for the development of farm irrigation systems is almost always economic. Water is considered an input to the farm enterprise just as are seed, fertilizer, labor, equipment, etc. In more humid regions, irrigation water serves to maintain production in years of drought. In slightly more arid regions, irrigation produces higher yields in a majority of years. In extremely arid regions, crop production relies entirely on water from irrigation. In the second case, the decision to supplement rainfall with irrigation water is an economic decision. If the expected benefit of increased yields more than offsets the cost of the irrigation system plus the cost of water, then development of the irrigation system is justified. In many cases, this can be considered a short-term investment. In the third case, development of a farm irrigation system is dependent on the economic feasibility of the entire farming enterprise. This is nearly always a long-term investment decision.