EFFECT OF WHEAT RESIDUE MANAGEMENT ON SOIL PROPERTIES AND ON SUNFLOWER YIELD IN DOUBLE CROPPING SYSTEM

Residue management has a direct impact on soil physical and chemical characteristics which in turn have identical effects on sustainability of crop production in agroecosystems. The effects of wheat residual management practices (burning, plowing under and removal) on soil physical and chemical characteristics were investigated in this research. Treatments were compared in a complete block design of four replications. The measured traits were: soil nitrogen, phosphorus, potassium, calcium, zinc and magnesium, soil organic matter, pH, bulk density as well as C/N. Soil nitrogen content in residue burning treatment decreased as compared to control, while potassium and phosphorus increased significantly. In residue plowing treatment soil nitrogsn significantly decreased because of a higher C/N ratio as compared to control. However, soil organic matter increased with an increase in C/N ratio. Wheat residue management affected soil pH and organic matter but it did not affect soil bulk density. The ploughing of residue significantly reduced the grain yield of sunflower. Burning wheat residue increased the grain yield of the succeeding crop; however, grain yield was not significantly different from those in other residue management practices.