AMELIORATION OF A SOLONETZIC SOIL BY SUBSOILING AND LIMING
The effect of subsoiling and liming on a Dark Brown Solodized Solonetz was investigated by measuring changes in physicochemical status, root penetration, soil moisture status, and crop yields. Major differences were due to subsoiling. The pH of the Ap was increased from 5.7 to 7.0 following liming but to greater than 8.0 following subsoiling. Subsoiling elevated calcium salts from depth thus improving subsurface soil structure; SAR values of the Bnt horizon decreased from approximately 12 to less than 7; moisture status and root penetration were increased at depth. Average yearly yield of wheat was increased by 0.9 Mg ha−1 following subsoiling. The addition of lime in combination with subsoiling did not improve physicochemical properties, moisture status, or crop yields as compared to subsoiling alone. Subsoiling increased the clay content of the Ap from 16 to 27%, this elevation of clay increased the crust strength of the Ap horizon and hence the potential for surface crusting. Key words: Solonetzic, amelioration, subsoiling, lime