SALT MANAGEMENT: A KEY TO IRRIGATION SUSTAINABILITY IN ARID CLIMATES

摘要

Salt management is a critical component of irrigated agriculture in arid regions. Successful croprnproduction cannot be sustained without maintaining an acceptable level of salinity in the rootrnzone. This requires drainage and a location to dispose drainage water, particularly, the salts itrncontains, which degrade the quality of receiving water bodies. Despite the need to generaterndrainage water to sustain productivity, many irrigation schemes have been designed andrnconstructed with insufficient attention to drainage, to appropriate re-use or disposal of salinerndrainage water, and to salt disposal in general. To control the negative effects of drainage waterrndisposal, state and federal agencies in several countries now are placing regulations on therndischarge of saline drainage water into rivers. As a result, many farmers have implementedrnirrigation and crop management practices that reduce drainage volumes. Farmers and technicalrnspecialists also are examining water treatment schemes to remove salt or dispose of salinerndrainage water in evaporation basins or in underlying groundwater. We propose that thernresponsibility for salt management be combined with the irrigation rights of farmers. Thisrnapproach will focus farmers' attention on salt management and motivate water delivery agenciesrnand farmers to seek efficient methods for reducing the amount of salt needing disposal and torndetermine methods of disposing salt in ways that are environmentally acceptable.