Tillage Management on Sustainable Rainfed Agricultural Resources

The aim of this study is to investigate the effects of plowing treatments on the volume of surface runoff, soil loss and crop yield, a research plan was implemented on hillslopes of the Sohrain Gharacharian floodwater spreading station in Zanjan province, Iran. Rainfall, surface runoff, sediment and crop yields were monitored in 1.8 wide x22.1 m long erosion plots. Two plowing treatments of contour and up and down the slope were compared on three slope classes of 0-12, 12-20 and 20-40% in triple replication and randomized complete block design in a regional wheat cropping experiment. Results demonstrated that contour plowing significantly reduced the volume of surface runoff and sediment yield in all slope classes. The amounts of reduction in all three slope classes were 83, 88 and 57% for runoff and 92, 97 and 95% for sediment, respectively. The volume of surface runoff and sediment yield from contour plowing of the 12-20 and 20-40% slopes were significantly lower compared to up and down the slope plowing of 0-12%. Similar results were obtained when comparing volume of surface runoff and sediment yield from contour plowing of 20-40% slope to up and down the slope plowing of 12-20%. Contour plowing resulted in soil loss that was 6.11, 7.73 and 7.73 times less than the soil loss threshold in 0-12, 12-20 and 20-40% slopes, respectively. The quantity and quality of crop yield did not change by plowing treatments. But, contour plowing increased the crop yield by 19, 21 and 9% on 0-12, 12-20 and 20-40% slopes, respectively.