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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 9/1/2011 Publication Date: 1/2/2012 Citation: Suarez, D.L. 2012. Irrigation water quality assessments. In: Wallender, W.W. and Tanji, K.K. (eds.) ASCE Manual and Reports on Engineering Practice No. 71 Agricultural Salinity Assessment and Management (2nd Edition). ASCE, Reston, VA. Chapter 11 pp. 343-370. Interpretive Summary: Increasing demands on fresh water supplies by municipal and industrial users in the semi arid and arid regions of the world raises questions about the sustainability of using these waters for irrigated agriculture. There is potential for agricultural use of treated wastewaters and low quality waters for irrigation but this will require consideration of the impact of the water on the soil physical properties as well as on crop production. Current water quality criteria were developed as simple criteria designed to avoid problems under most conditions. It is suggested that the focus be on describing the impact of the water quality parameter on soil properties and crop production and utilizing the results to develop site specific recommendations. New guidelines are developed for SAR and EC criteria as well as use of high B containing waters. These guidelines will allow for management practices to better utilize marginal quality waters for irrigation. Technical Abstract: Increasing demands on fresh water supplies by municipal and industrial users means decreased fresh water availability for irrigated agriculture in semi arid and arid regions. There is potential for agricultural use of treated wastewaters and low quality waters for irrigation but this will require consideration of the impact of the water on the soil physical properties as well as on crop production. Current water quality criteria were developed as simple criteria designed to avoid problems under most conditions. Consideration of site specific conditions is necessary for better water utilization. Many waters considered unsuitable have value under specified climatic, soil and management conditions. Rather than classification of waters as suitable and unsuitable it is more useful to develop predictive relationships that describe how certain water quality parameters impact crop and soil responses. Incorporation of this information into models such as SWS, will allow evaluation of when and under what conditions low quality waters can be used for irrigation at specific sites. New guidelines are developed for SAR and EC criteria as well as use of high B containing waters. |
