Dealing with the impact of climate change-induced drought on the management of soil salinity under irrigated arid-zone agriculture

Authors: Corwin, Dennis

Submitted to: Advances in Agronomy
Publication Type: Review Article
Publication Acceptance Date: 9/25/2023
Publication Date: 1/27/2024
Citation: Corwin, D.L. 2024. Dealing with the impact of climate change-induced drought on the management of soil salinity under irrigated arid-zone agriculture. Advances in Agronomy. https://doi.org/10.1016/bs.agron.2023.12.001.
DOI: https://doi.org/10.1016/bs.agron.2023.12.001

Interpretive Summary: a) Problem Statement Soil salinity has a major impact on global agricultural productivity with an estimated global economic loss of USD 27.3 billion in 2013. Current and future climate change-induced impacts on arid and semi-arid irrigated agricultural areas will increase the frequency and extent of droughts with a concomitant increase in soil salinity in many areas. To conserve water in water-scarce agricultural areas impacted by climate change, site-specific micro-irrigation management systems are needed to remove sufficient salinity from the root zone to minimize the crop yield decrement due to the detrimental impacts of soil salinity while significantly conserving water beyond current micro-irrigation management protocols and guidelines. b) Accomplishment This climate-smart technology paper discusses the integration of state-of-the-art technological concepts behind site-specific soil salinity management with micro-irrigation systems using minimal leaching to conserve water in water-scarce arid and semi-arid agricultural areas impacted by climate change. The state-of-the-art technological concepts include field-scale soil salinity mapping of fields under micro-irrigation systems, leaching requirement derived from transient models, site-specific plant salt tolerance studies, site-specific micro-irrigation management, and degraded water reuse. c) Contribution This paper presents a framework for site-specific soil salinity management with micro-irrigation systems, which can be effectively used for precision agriculture and water conservation applications by NRCS staff, agricultural consultants, natural resource specialists, and soil scientists in the university, government, and private sectors. This climate-smart technology is particularly applicable to agricultural areas that use micro-irrigation to control soil salinity as a means of coping with the climate change-induced impact of droughts on water-scarce, arid and semi-arid agricultural areas.

Technical Abstract: Climate change will cause an increased frequency and intensity of drought in irrigated arid-zone agricultural areas resulting in a greater need for water conservation. Water-scarce agricultural areas, such as California’s San Joaquin Valley (SJV), have shifted from sprinkler and flood irrigation on low cash crops to micro-irrigation on high cash crops, which is a continuing trend throughout the world. As prolonged droughts place increasing demands on water conservation, not only will micro-irrigation systems on high cash crops become more prevalent, but greater focus will be placed on site-specific management of micro-irrigation systems to maximize their water efficiency. Site-specific micro-irrigation management (SSMIM) will play a crucial role in maintaining the future productivity of water-scarce agricultural areas like the SJV. It is the objective of this paper to present a review and integration of the concepts for managing soil salinity utilizing SSMIM. The topics covered include (1) apparent soil electrical conductivity soil sampling for mapping soil spatial variability and soil salinity under micro-irrigation, (2) use of data fusion to improve the mapping of soil spatial variability, (3) an alternative plant salt tolerance approach to provide site-specific plant salt tolerance parameters (i.e., plant salt tolerance threshold and yield decrement slope percentage) to more accurately determine leaching requirement (LR), (4) determination of LR using sophisticated transient models, (5) water reuse as another water source for water-scarce irrigated agricultural areas, (6) infrastructure and knowledge adjustments that are needed to operate site-specific micro-irrigation systems, and (7) existing knowledge gaps that need to be filled before site-specific micro-irrigation can come to fruition. California’s San Joaquin Valley, Imperial Valley, and Napa Valley are used to explain the concepts behind SSMIM. The climate-smart technology presented is of value and benefit to producers, agriculture consultants, water conservationists, irrigation specialists, cooperative extension specialists, Natural Resources Conservation Service field staff, and soil and water researchers.