Effect of Residue Management, Different Conservation Tillage and Seeding on Soil Physical Properties and Wheat Grain Yield

Crop residue management has a large impact on soil physical properties and also crop grain yield. To investigate the effect of conservation tillage methods and different amount of wheat stubble on soil surface a study was conducted in 2011. A split-split complete randomized block design was applied with three replications. Crop residue treatments including 0 residue، 45 percent and 90 percent of soil covered by stubble in the main plots and tillage treatments including two passes combined tillage، moldboard plow followed by double disc and without till seeding in sub plot and sowing treatments including flat and raised bed planting were located in sub-sub plots. Soil moisture content، bulk density، cone index and soil moisture content at depth 0-10 and 10-20 cm were recorded. Without-tillage with an average 18. 7% moisture content was shown the highest moisture content at seedling emergence. The 90 percent residue increased soil moisture content compared to no residue treatment. The 45% residue treatment using two pass combination tillage and then raised bed planting produced the highest (7924. 9 kg ha-1) grain yield.