Economic Evaluation of using Different Tillage Methods and Crop Rotation in Rain-Fed Wheat Cultivation

Soil protection against water and wind erosion is of great importance. Since most soils of arid and semi-arid regions of Iran are poor in organic matter and continuous use of conventional tillage (moldboard plow) has increased the severity of soil organic matter depletion and degradation of soil structure. Therefore replacing conventional tillage with conservation tillage (reduced tillage and no tillage) is needed to improve soil structure and increase soil organic matter. Due to the increasing population growth and the limitation of arable land, it is necessary to remove the fallow year in dryland. Legumes are crops that can be in rotation with wheat.

This study was conducted to evaluate the effect of crop rotation and different tillage systems on rain-fed wheat farming in Kaboudarahang Township during 2012-2014. The experiment was conducted as split-plot in a randomized complete block design with three replications. In this study, different crop rotations including fallow-wheat rotation, and chickpea-wheat rotation as main plots and different tillage systems including conventional tillage (moldboard plow + power harrow), conservation tillage (chisel plow equipped with roller), conservation tillage (sweep plow equipped with roller) and direct drilling were investigated as subplots.In the economic evaluation of this project, the economic impacts of the treatments were analyzed using the partial budgeting method and the cost-benefit ratio. For this purpose, the difference between treatments income and cost compared with control treatment has been calculated and compared. The differences in the benefits of the treatments are due to the different yields of wheat.

Results showed: 1- The highest wheat yield in the first and second years of the study was 605.3 and 2135.1 kg ha-1, respectively in rotation of fallow wheat. 2- In the first year, the highest wheat yield (690.7 kg ha-1) was related to direct planting (no tillage), but in the second year, the highest yield (2268.6 kg ha-1) was related to conservation tillage (sweep blades + roller). 3- In the first and second year, the highest value of treatment was related to direct planting and conservation tillage (sweep tiller + roller), respectively. 4- In the chickpea-wheat rotation, the highest net income in the first and second year was related to direct planting and conservation tillage (sweep + roller), respectively. Thebenefit-cost ratio in the conservation tillage (sweep + roller) (second year) and direct drilling (first year) methods shows that for each rial of expenses, 5.7 and 2.8 rials can be earned respectively. Therefore, economically, these tillage treatments are superior to the control treatment (conventional cultivation).5- In the wheat rotation, the highest net income in the first and second year was related to direct planting and conservation tillage (sweep + roller), respectively. The benefit-cost ratio in the conservation tillage (sweep + roller) (second year) and direct drilling (first year) methods shows that for   each rial of expenses, 4.2 and 1.3 rials can be earned respectively. Therefore, it is economically justified and these tillage treatments are superior to the control treatment (conventional tillage).

The results of this study showed that in the first and second years, economically the direct method and the conservation tillage treatment (sweep blades + roller) were superior to the conventional method, respectively. Therefore, conservation tillage methods can be replaced by the conventional method (plowing with moldboard plow) in dryland farming. Also, in dry years, direct cultivation (no tillage) is a good and economical method.