Effect of irrigation on salt and sodium content of salt affected soils in central Nebraska

Abstract

The effect of irrigation water of good quality on the salt and sodium content of some Halaquepts on the floodplain of the Platte River in Central Nebraska was determined. The study compared salts and sodium concentrations in A and B horizons of adjacent soils in 3 fields within a single delineation of a map unit. Land uses were long term irrigation, recent introduction to irrigation, and permanent pasture that had never been cultivated or irrigated. The presence of a salt crust on the surface of the field that had been irrigated for some time led the farm operator to believe that irrigation was increasing salt problems within the field. The objective of the study was to determine whether or not this was true. Salt content, sodium absorption ratio, and exchangeable sodium values were not greater in the irrigated field than in the permanent pasture. Salt contents of A horizons were the same in all fields, whereas B horizon salt content tended to be lower where both long and short term irrigation had been practiced. Sodium absorption ratios and exchangeable sodium percentages followed the same pattern as that of soluble salts. Irrigation with water of good quality appeared to be decreasing both salt and sodium content of these soils.