Soil Management

Sodic Soils and Their Management

Alan Blaylock, Ph.D.

Alan Blaylock, Ph.D.


Senior Agronomist

Dr. Alan Blaylock brings extensive North American and international experience in nutrient management to the agronomy team. University studies and service as a university extension soils specialist prepared him for a long career in the fertilizer industry. Having managed both domestic and global research and education programs, Dr. Blaylock has a wealth of experience in applying science-based nutrient management principles and products to solving practical questions. Dr. Blaylock earned Bachelor of Science and Master of Science degrees in agronomy and horticulture from Brigham Young University and a Ph.D. in soil science from Iowa State University. He has been in agriculture his entire life — from his childhood on an irrigated farm in eastern Oregon to teaching soil science at Iowa State University to his current role as an agronomist at Nutrien. These diverse experiences helped Dr. Blaylock develop the skills to excel in translating complex scientific principles into practical solutions. Although early in his university studies he explored computer science as a profession, deep family roots in agriculture brought him back to the people and values of his heritage. His career satisfaction comes from helping others improve the performance of nutrients and cropping systems.

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Sodic soils, occurring mainly in arid and semi-arid regions, are especially challenging to manage. They may result from high water tables and/or poor-quality irrigation water. High exchangeable sodium in the soil creates undesirable physical properties, such as poor structure, crusting, clay dispersion, poor infiltration, and poor aeration. These soils also exhibit high pH, typically greater than 8.5. Soil sodicity refers to the amount of sodium held on soil cation exchange sites.

It is typically expressed either as the percentage of the soil cation exchange capacity filled with sodium ions (exchangeable sodium percentage or ESP), or as a ratio comparing exchangeable sodium to exchangeable calcium plus magnesium (sodium adsorption ratio or SAR). Sodic-soil reclamation typically requires large additions of soluble calcium amendments, such as gypsum, or addition of acids to dissolve calcium carbonate in the soil and increase calcium in the soil solution. Dr. Jim Walworth, University of Arizona explores the relationship between soil salinity, soil sodicity, and soil physical properties and how to manage these difficult soils. Download the report here.

Dr. James Walworth, Department of Soil, Water and Environmental Science, University of Arizona, Tucson, Arizona, Western Nutrient Management Conference. 2019. Vol. 13. Pg. 21. Reno, NV.