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United States Department of Agriculture

Agricultural Research Service

Research Project: SALINITY AND TRACE ELEMENTS ASSOCIATED WITH WATER REUSE IN IRRIGATED SYSTEMS: PROCESSES, SAMPLING PROTOCOLS, AND SITE-SPECIFIC MANAGEMENT Title: Extent of Global Salinization and Management Options for Sustainable Crop Production

Authors
item SUAREZ, DONALD
item SUAREZ, DONALD

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: December 31, 2009
Publication Date: January 11, 2010
Citation: Suarez, D.L. 2010. Extent of Global Salinization and Management Options for Sustainable Crop Production. Proceedings of the International Conference on Soils and Groundwater Salinization in Arid Regions. Held January 11-14, 2010 at the Sultan Qaboos Univeristy, Muscat, Sultanate of Oman.

Interpretive Summary: Global irrigated acreage in arid regions has already started to decline due to unsustainable utilization of fresh water. Meeting the food needs of these regions will require more efficient use of present resources as well as utilization of lower quality waters and reuse of drainage and municipal waste waters. Management practices need to be carefully examined for the potential for more efficient water utilization. As shown in an example, there is a large discrepancy between current models of plant response to salinity and the widely utilized guidelines, suggesting that less leaching is required when irrigating with moderately saline waters. In contrast, current guidelines also suggest saline waters do not pose a sodicity and infiltration problem, yet recent findings indicate that in the presence of rain, the sodicity hazard is of concern, and surface amendments likely required. Recent improved understanding of the effects of salinity on plant growth provides numerous approaches for improving the salt tolerance of sensitive plants. This information is of particular interest to irrigation specialists who make recommendations regarding water suitability for irrigation and growers evaluating their water requirements for salinity control.

Technical Abstract: Irrigated acreage in arid regions of the world has recently stopped increasing and it will be difficult to even maintain existing levels of irrigation in these regions. At the same time the amount of salt affected soils in the world, continues to increase, with a major part being secondary salinization in irrigated lands. Since this salinization is caused primarily by over irrigation, more uniform irrigation application systems allow for reductions in quantities of water applied, and paradoxically may reduce soil salinity, due to lowering of shallow water tables. Model simulations of irrigation with saline waters confirms field data indicating that existing guidelines overestimate water quantities needed for salinity control in the root zone. The sodicity hazard associated with application of saline water has been generally overlooked, due primarily to lack of consideration of the adverse impact of even small quantities of rain on physical properties of the soil surface. Recent improved understanding of the effects of salinity on plant growth provides numerous approaches for improving the salt tolerance of sensitive species.

Last Modified: 9/10/2014
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