Climate change impacts on soil salinity in agricultural areas

Authors: Corwin, Dennis

Submitted to: European Journal of Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2020
Publication Date: 6/12/2020
Citation: Corwin, D.L. 2020. Climate change impacts on soil salinity in agricultural areas. European Journal of Soil Science. 72(2):842-862. https://doi.org/10.1111/ejss.13010.
DOI: https://doi.org/10.1111/ejss.13010

Interpretive Summary: Agriculture and climate change are directly linked. Crop yield, water use, biodiversity, and soil health are directly affected by changes in climate. The impact of climate change on soil properties and processes that influence plant productivity have been studied for a variety of properties, but to a lesser extent for soil salinity. It is the objective of this paper to evaluate the impact of climate change on soil salinity development in agricultural areas of the world. Case studies are presented for California’s San Joaquin Valley (SJV), Minnesota’s Red River Valley (RRV), Bangladesh, Gaza Strip, and Australia’s Murray-Darling River Basin. The case studies reflect the impact of climate change on different aspects of the soil salinization process, including the reuse of low quality water in areas of water scarcity, upward movement of salts from shallow water tables, and seawater intrusion from rising sea levels. Ground and satellite sensor protocols for mapping soil salinity at multiple scales are presented for field- (< 1 km2), landscape- (1-10 km2), and regional-scale (10-105 km2). Soil salinity assessments using sensors indicate that the California drought of 2011-2015 caused an appreciable increase in soil salinity in the root zone in the SJV while salinity assessments of Kittson County in the RRV indicate increased soil salinity from above average rainfall creating shallow water tables from which upward movement of salts occurred. The likelihood of increased root zone soil salinity in arid and semi-arid areas agricultural of the world suggests that an infrastructure is needed to monitor soil salinity at local, state/province, national, and global scales for agriculturally productive arid and semi-arid areas. Soil and agronomic researchers, irrigation specialists, producers, consultants, conservation and irrigation districts, commodity groups, cooperative extension, federal and state regulators and agencies, and the United Nation’s Food and Agriculture Organization will directly benefit from timely salinity monitoring maps from ground- and satellite-based sensors.

Technical Abstract: Changes in climate patterns are dramatically influencing some agricultural areas. Arid, semi-arid, and coastal agricultural areas are especially vulnerable to climate change impacts on soil salinity. Inventorying and monitoring climate change impacts on salinity are crucial to evaluate the extent of the problem, to recognize trends, and to formulate irrigation and crop management strategies that will maintain the agricultural productivity of these areas. Over the past 3 decades, Corwin and colleagues at the U.S. Salinity Laboratory have developed proximal sensor and remote imagery methodologies for assessing soil salinity at multiple scales. The objective of this paper is to evaluate the impact climate change has had on selected agricultural areas experiencing weather pattern changes with a focus on the use of proximal and satellite sensors to assess salinity development. Evidence presented for case studies for California’s San Joaquin Valley (SJV) and Minnesota’s Red River Valley (RRV) demonstrates the utility of these sensor approaches in assessing soil salinity changes due to changes in weather patterns. Agricultural areas are discussed where changes in weather patterns have increased root-zone soil salinity, particularly in areas with shallow water tables (SJV and RRV), coastal areas with seawater intrusion (e.g., Bangladesh and Gaza Strip), and water-scarce areas potentially relying on degraded groundwater as an irrigation source (SJV and Murray-Darling River Basin). Trends in salinization due to climate change indicate that the infrastructure and protocols to monitor soil salinity from field to regional to national to global scales are needed.