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Show The Situation Supplementary irrigation has been expanding rapidly in the Ohio Basin and is becoming an im- portant farming practice for certain specialized crops. In recent years many farmers have adopted irrigation to insure an even flow of water to their crops throughout the growing season. The number of acres irrigated, when compared with the total cropland, is relatively small. Com- prehensive statistics are lacking but observations indicate that during the last 5 years hundreds of farmers have installed equipment for sprinkler irri- gation. Recent information indicates that the acreage irrigated in 1950 is about 20 times the acreage irrigated in 1944. The United States Census reported that in 1944 there were 5,008 acres of crops harvested from irrigated land in the States of Ohio and Indiana. It has been estimated that the total land irrigated in the humid areas of the eastern United States is in excess of 1.5 million acres. A small amount of irrigation has been used for years, primarily on tracts producing floral, nursery, fruit, and truck crops. The post World War II period, however, has brought a surge of interest and activity in the use of supplemental irrigation. The current expansion stems from several factors: the development of new types of portable light- weight irrigation equipment; the distribution of electrical power to approximately 85 percent of the farms in the Ohio Basin; advances in farm techniques, particularly use of fertilizers that re- quire more moisture for optimum use than is sup- plied by natural precipitation; and postwar levels of farm income that have both permitted and favored substantial investments in new equipment. Supplemental irrigation in the basin has gener- ally been developed by individual farmers. Large- scale community development of irrigation lies far in the future, when the needs of the Nation for farm products are much greater than now. For the next several years many factors will tend to keep irrigation development relatively small and on an individual farm development basis. Most important are. the expansion which can be brought about without large-scale irrigation developments, and the small amount of water needed to make up for poor distribution of rainfall and as insurance against certain extended periods of drought. Approximately 60 percent of the irrigation water used comes from streams, ponds, and other surface sources and 40 percent from ground water supplies. State regulations regarding the use of waters for irrigation hold generally to the rule of reasonable use, or are governed by the riparian doctrine. Various preliminary experiments carried out in nearly every State within the basin indicate that supplemental irrigation will produce large, in some cases phenomenal, increases in yields of crops and pastures. To illustrate: results in both Ohio and Indiana show increases of more than 100 percent in yield of strawberries. In Tennessee, yields of tobacco and cabbage were more than doubled. Yields of snap beans were multiplied as much as seven times. Substantial gains were recorded for potatoes, cantaloupe, squash, okra, and tomatoes. Investments in irrigation equipment and the de- velopment of irrigation facilities can be very high. Costs, excluding wells or other facilities on irrigated tracts from 20 to 60 acres, may run from $60 to $100 per acre. The economic question of whether the increased production and farm income is ade- quate to justify the higher cost is yet to be deter- mined. On a basis of present information, the ben- efits appear to outweigh the disadvantages. This is especially true on intensely farmed lands, par- ticularly on lands growing vegetable and fruit crops and, to some extent, in dry seasons on pasture lands and field crops. Conclusions With improved types of equipment, wider dis- tribution of electrical power, and advances in farm techniques, expansion of supplemental irrigation in the basin is likely to continue. Plans for com- prehensive development of water resources of the basin need not provide for irrigation facilities. They should, however, be kept flexible enough to provide for certain irrigation improvements, should such a need arise. Conflicts have already appeared in connection with the use of water for supplemental irrigation. As this system of farming expands, such conflicts will become more and more evident. The States should consider legislation needed to permit the orderly development of sup- plemental irrigation and to protect the rights of water users. Attention should also be given to pro- tecting underground water supplies against over- drafts in areas where such drafts conflict with other demands. Experimental studies on the use of sup- plemental irrigation should be continued and in some cases expanded to determine not only the values, but also the solution of problems associated with irrigated agriculture. 683 911610-51- |