Water Quality Effects on Soils and Alfalfa: II. Soil Physical and Chemical Properties

Abstract

AbstractSalt accumulation can occur in northern Great Plains soils during irrigation with saline water. The objective of this study was to quantify effects of salinization produced in Barnes loam (fine‐loamy, mixed Udic Haploboroll), Parshall loam (coarse‐loamy, mixed Pachic Haploboroll), Svea loam (fine‐loamy, mixed Pachic Haploboroll), and Williams loam (fine‐loamy, mixed Typic Argiboroll) soils by irrigation with seven water qualities during 21 mo of greenhouse alfalfa production in undisturbed columns. Eight physical and chemical soil properties were evaluated and related to soil, water quality, and depth in the soil. Saturation percentage (SP) of the soil increased 0.2% for each unit increase in soil‐extract sodium adsorption ratio (SARe). Saturation‐extract electrical conductivity (ECe) increased with depth, at rates dependent on water quality, to maximums of 1 to 17 ds m−1. Parshall was the soil most susceptible to dispersion as SARe increased. From the surface to 15‐cm depth, bulk density was reduced 0.04 to 0.06 Mg m−3 by the water that resulted in the highest soluble‐Ca concentration. Significant regression models were developed for SP, ECe, SARe, and salt precipitation. Parshall, the most irrigable soil, was the most detrimentally affected, as judged by dispersion, ECe, and SARe, indicating a need for further investigation. Barnes, Svea, and Williams soils proved more suited to irrigation than previously believed.