EFFECT OF SUBSOILING ON WHEAT YIELD AND SALT DISTRIBUTION OF A SOLONETZIC SOIL

The effects of subsoiling, deep ripping to 52 cm depth, in the amelioration of a Solonetzic soil under irrigated and nonirrigated conditions were examined at the Vauxhall Research Substation in Alberta. All plots were fertilized by broadcasting N and P2O5 at rates of 80 and 42 kg ha−1, respectively. Hard spring wheat (Triticum aestivum L. ’Neepawa’) was grown annually from 1980 to 1984. The plot area had a high degree of spatial variability in both physical and chemical properties of the soil. Subsoiling in the fall of 1979 and 1980 had no significant effects on soil salinity and sodicity or on wheat yield under nonirrigated conditions. However, under irrigated conditions, subsoiling enhanced the downward movement of salts and had a significant overall profile (to 90 cm) effect on soil salinity and sodicity, but it had no significant effect among depths within the profile. Subsoiling also had no significant effect on wheat yield under irrigated conditions. Irrigation alone improved the soil salinity and sodicity conditions, increased wheat yields, and reduced yield variability. Key words: Amelioration, irrigation, salinity, sodicity, spatial variability