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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 10/8/2014 Publication Date: 3/2/2015 Citation: Corwin, D.L. 2015. Use of advanced information technologies for water conservation on salt-affected soils. In:Mueller, T., Sassenrath, G.F., editors. GIS applications in agriculture. Conservation planning. Volume 4. Boca Raton, FL:CRC Press. p. 119-150. Interpretive Summary: Some of the most productive agricultural lands in the world are found in water-scarce arid zone regions, such as California’s San Joaquin and Imperial-Coachella Valleys and other arid regions of the world including the Middle East; the Hai He, Huang He and Yangtze basins in China; and along the Nile River in Egypt. Water scarcity is an identifying feature of arid and semi-arid regions of the world, causing water conservation to be a constant consideration in these areas. Due to the unpredictability and scarcity of natural precipitation in arid and semi-arid regions, irrigation is essential for maintaining crop productivity. In general, irrigated agriculture and soil salinity accumulation go hand-in-hand, particularly in the arid zones of the world. Water conservation on arid and semi-arid soils must be done with constant and careful consideration of the distribution of salinity across the landscape and through the soil profile. Salinity is of concern because it causes a significant decrease in crop productivity due to osmotic and toxic ion effects on plant growth. The field-scale management of soil salinity is best handled with knowledge of its spatial and temporal distribution. Ideally, water conservation on irrigated agricultural lands is best achieved by applying irrigation water where, when, and in the amounts needed to adequately leach salts and to meet the crop’s water needs. This can be achieved by site-specific irrigation, which accounts for within-field variation of water content and salinity. It is the goal of this book chapter to provide an overview of the approach for delineating site-specific irrigation management units (SSIMUs) from the field-scale characterization of soil salinity, water content, and texture distributions using advanced information technologies. Guidelines, special considerations, protocols, and strengths and limitations are presented. Maps of SSIMUs provide irrigation management information to ameliorate crop yield reduction on salt-affected soils with minimal irrigation water requirements. Land resource managers, water conservation specialists, farmers, extension specialists, and Natural Resource Conservation Service field staff are the beneficiaries of field-scale maps of soil salinity, water content, texture, and SSIMUs, which can be used for crop selection, irrigation and salinity management, and remediation. Technical Abstract: Water conservation on arid and semi-arid soils must be done with constant and careful consideration of the distribution of salinity across the landscape and through the soil profile. Soil salinity can be managed through leaching and the application of various soil amendments. The field-scale management of soil salinity is best handled with knowledge of its spatial and temporal distribution. Ideally, water conservation on irrigated agricultural lands is best achieved by applying irrigation water where, when, and in the amounts needed to adequately leach salts and to meet the crop’s water needs. But, this is not easily done since water content and salinity are highly variable across a field and through the root zone both spatially and temporally. However, site-specific irrigation will account for within-field variation of water content and salinity. Field-scale salinity measurement and mapping protocols have been developed by Corwin and his colleagues at the U.S. Salinity Laboratory in Riverside, CA. These protocols utilize advanced information technologies (i.e., geophysical techniques measuring apparent soil electrical conductivity, GIS, geostatistics, spatial statistical analysis, and spatial statistical sampling designs) to map the spatio-temporal distribution of soil salinity for management applications. These protocols and technologies also have the potential to map soil water content and texture in most instances. It is the goal of this chapter to provide an overview of the approach for delineating site-specific irrigation management units (SSIMUs) from the field-scale characterization of soil salinity, water content, and texture distributions using advanced information technologies. Guidelines, special considerations, protocols, and strengths and limitations are presented. Maps of SSIMUs provide irrigation management information to ameliorate crop yield reduction on salt-affected soils with minimal irrigation water requirements. Land resource managers, water conservation specialists, farmers, extension specialists, and Natural Resource Conservation Service field staff are the beneficiaries of field-scale maps of soil salinity, water content, texture, and SSIMUs, which can be used for crop selection, irrigation and salinity management, and remediation. |
