Document Type


Publication Date



Expanding sodicity and salinity problems have placed many northern Great Plains (NGP) soils at the sustainability tipping point. This study assessed the impact of chemical restoration on water and salt transport in undisturbed soil columns collected from three hillslope model landscape positions. The backslope (Redfield), footslope (White Lake), and toeslope (Pierpont) soils had moderate (3.27 ± 0.59), high (7.3 ± 3.34), and very high (13.29 ± 3.2) sodium adsorption ratio (SARe) values, respectively. The soils were treated with KBr and one of four soil amendments (none, H2SO4, CaSO4, and CaCl2). The rapid movement of Brthrough the columns suggested that bypass water flow occurred. In addition, a comparison with widely used salinity models (final EC = 0.8 × initial EC/pore volume [PV]) underestimated the leaching requirements by 69, 79, and 41% in the backslope, footslope, and toeslope soils. In the footslope soils with high SAR values, H2SO4 was more effective at promoting Na+leaching than gypsum or CaCl2. However, in back slope and toeslope soils with moderate and very high SAR values, the chemical amendments were not, and were equally effective at facilitating Na+ leaching, respectively. These findings suggest that chemical amendments should target treatments to problem areas, and that bypass flow can influence their effectiveness. The LOESS regression model suggested that the electrical conductivity (ECe)/SARe ratio was useful for assessing Na+ risks, and that to maintain a water flow rate of 1 mm h–1 in a soil with a SARe value of 1, an ECe value of ≥2 was required.

Publication Title

Agronomy Journal





First Page


Last Page


DOI of Published Version



American Society of Agronomy


Copyright © 2018 by the American Society of Agronomy

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.


This is an open access article originally published in Published in Agron. J. 110:1103–1110 (2018) doi:10.2134/agronj2017.07.0416