Effect of Depth of Plowing and Soil Moisture Content on Reduced Secondary Tillage
This study was carried out to investigate the effect of depth of plowing and soil moisture content dry base on reduce secondary tillage. Split plots have been used for statistical analysis. The Main plot was used for the percentage of soil moisture content and the sub-plot was used for investigation of the effect of depth of plowing. Each treatment was replicated 3 times. For primary tillage and secondary tillage moldboard plow and disk harrow was used, respectively. This research was done in two different land types, one land type had silty clay loam soil and another had loam soil. Based on this research, in silty clay loam soil, the clod mean weight diameter of soil was minimum for each two depth of plowing 15-20 and 25-30 cm with 15-18 % of soil moisture content, and it was maximum for the same depth but with 10-13 % of soil moisture content. In loam soil, clod mean weight diameter was minimum for 15-20 cm depth of plowing with 18-20 % of soil moisture content and 25-30 cm depth of plowing with 13-18 % of soil moisture content, and it was maximum for two depth of plowing 15-20, 25-30 cm with 10-13 % soil moisture content. Results showed that, if primary tillage was performed in optimum soil moisture content, based on type of soil, we will have suitable seedbed with minimum secondary tillage. It can reduce costs of secondary tillage.