Author
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Sojka, Robert |
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Submitted to: Yearbook of Science and Technology
Publication Type: Book / Chapter Publication Acceptance Date: 1/1/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Book Chapter - No interpretive summary required Technical Abstract: Recently some have argued that irrigation's environmental, economic and political problems exceed the benefits derived form irrigation development. These contentions disregard the extent of irrigation's role in meeting human needs and preserving earth's environment. About 3.0-3.5 billion acres are cultivate world wide. Only about 600 million acres (15-17% of the cropland total) are irrigated. This 1/6 of the total produces over 1/3 of the global harvest, and between 1/3 and 1/2 the value of crops produced. Irrigated crops usually have improved quality. A mere 125 million irrigated acres (about 4% of the cropland total) produces 1/3 the global food-crop harvest. Because most irrigation is in arid climates and on low organic matter-high base saturation soils, crop production requires less potassium fertilizer, little liming, less soil applied herbicides and fewer pesticides. Irrigation's greater efficiency, and predominate association with arid and semi-arid environments, means fewer species are eliminated or displaced by irrigation than for equivalent output from rainfed agricultural development in its more richly speciated environments. Irrigation also provides greater production reliability (food security) and irrigation projects often have side benefits of water-based transportation, recreation, flood control, and hydropower. |
