IRRIGATION SUITABILITY OF SOLONETZIC SOILS IN THE COUNTY OF NEWELL, ALBERTA

Abstract

A 5-yr study was conducted in the County of Newell to monitor soil salinity and sodicity, water-table levels and crop production on Solonetzic soil associations under normal irrigation management practices. All soil associations consisted of at least 50 percent Solonetzic Order soils, with Brown Solod as the dominant subgroup at all but one site. Changes in soil quality were monitored through regular measurements of water-table levels, annual fall sampling and chemical analysis of soils. Irrigation practises used by farmers did not permanently raise water-table levels at any of the sites irrigated by center pivots. Changes in soil salinity or sodicity as a result of irrigation were generally not statistically significant, suggesting that the salt status of soils at most sites did not change appreciably over the 5-yr period. The relatively low productive capability of land units dominated by Solonetzic soils was evident in the low yield and by a high degree of variability in yield within individual sites. Careful irrigation management partially compensated for some of the soil limitations in these Solonetzic soil landscapes; however, due to the low productivity observed, modification of existing land classification standards to allow irrigation of Solonetzic soils is not presently recommended. Key words: Irrigation suitability, Solonetzic soils, productive capability