Author
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UNGER, PAUL - USDA-ARS, RETIRED |
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Submitted to: Encyclopedia of Soil Science
Publication Type: Popular Publication Publication Acceptance Date: 1/15/2002 Publication Date: 6/1/2002 Citation: N/A Interpretive Summary: Soil-water conservation is important for crop production in all climatic regions, and is critical in subhumid, semiarid, and arid regions. Demands for water for agricultural and non-agricultural purposes are increasing in many places. As a result, water conservation is becoming increasingly important in some regions. Improved soil-water conservation depends on increasing infiltration and reducing evaporation, use by weeds, and deep movement into the soil profile. Practices for increasing infiltration include keeping the soil covered with plants or a mulch to reduce surface seal development and to hinder runoff; applying materials to stabilize the soil surface; and using tillage to loosen sealed soil surfaces, provide for temporary water storage depressions on the surface, and loosen subsurface layers that hinder water movement. Evaporation can be reduced by a mulch of crop residues or plastic films on the soil surface. Weeds can be controlled by tillage or herbicides. Deep movement of water can be reduce by matching crop growing seasons to seasons when water excesses are most likely, increasing soil water storage capacity, loosening the soil to allow deeper plant rooting, growing deep-rooting crops, and installing subsurface barriers that impede deep drainage. Technical Abstract: Soil-water conservation is important for crop production in all climatic regions, and is critical in subhumid, semiarid, and arid regions. Increasing demands for water for agricultural and non-agricultural purposes make water conservation increasingly important in some regions. Improved soil-water conservation depends on increasing infiltration and reducing evaporation, transpiration (by weeds), and deep drainage losses. Practice for increasing infiltration include keeping the soil covered with plants or a mulch to reduce surface seal development and to impede runoff; applying materials to stabilize the soil surface; and using tillage to disrupt sealed soil surfaces, provide for temporary depressional water storage on the surface, and disrupt subsurface layers that impede water movement. Evaporation can be reduced by a surface mulch (crop residues or plastic films). Weeds can be controlled by tillage or herbicides. Deep drainage can be minimized by matching crop growing seasons to seasons when water excesses are most likely, increasing soil water storage capacity, loosening the soil to allow deep plant rooting, growing deep-rooting crops, and installing subsurface barriers that impede deep drainage. |
