RESEARCH, REVIEWS, PRACTICES, POLICY AND TECHNOLOGY Crop Response in Salt-Affected Soils

Salt-affected soils, those on which plant growth is limited by an excess of salts, are of three types: (i) saline soils in which electrical conductivity is > 4 dSm 1; (ii) sodic soils in which the exchangeable sodium percentage (ESP) is > 15; and (iii) saline-sodic in which the electrical conductivity (EC) is > 4 dSm 1 and ESP is > 15. Salt-affected soils are most common in aridic moisture regimes, and secondary salinization A. Eynard was affiliated with The Ohio State University, Carbon Management and Sequestration Center, 2021 Coffey Road, Columbus, OH 43210 USA. A. Eynard’s present address: South Dakota State University, Plant Science Department, Box 2140C, NPB 247, Brookings, SD 57007-2141 (E-mail: [email protected]). R. Lal is affiliated with The Ohio State University, Carbon Management and Sequestration Center, School of Natural Resources, 2021 Coffey Road, Columbus, OH 43210 USA. K. Wiebe is affiliated with the USDA-ERS, 1800 M Street N.W., Room 4198, Washington, DC 20036 (E-mail: [email protected]). Address correspondence to: R. Lal at the above address (E-mail: [email protected]). The views expressed here are those of the authors, and may not be attributed to the Economic Research Service or the US Department of Agriculture. Journal of Sustainable Agriculture, Vol. 27(1) 2005 Available online at http://www.haworthpress.com/web/JSA © 2005 by The Haworth Press, Inc. All rights reserved. doi:10.1300/J064v27n01_03 5 (due to anthropogenic activities such as irrigation) may occur by improper management of irrigation. Estimates of the area of salt-affected soils vary widely, ranging from 6% to 10% of earth’s land area, and 77 million hectares (Mha) of irrigated lands. Crop yields are drastically affected due to lack of availability of water, nutrients, and oxygen in the root zone. The magnitude of yield reduction depends on the crop, soil type, and management. The reduction in yield normally ranges from 10% to 90% for wheat, 30% to 50% for rice, 50% to 75% for cotton, and 30% to 90% for sugarcane. Crop yield can be enhanced by nutrient management (especially N), water management (irrigation with good quality water and appropriate drainage), use of soil amendments (manures and gypsum, etc.), and use of salt-tolerant varieties.[Article copies available for a fee from The Haworth Document Delivery Service: 1-800-HAWORTH. E-mail address: Website: © 2005 by The Haworth Press, Inc. All rights reserved.]