- Effect of Tillage Methods on Oxygen Diffusion Rate (ODR), Power and Fuel Requirements, Some Soil Physical Properties and Wheat Yield
Three types of tillage implements including moldboard plow (conventional tillage), heavy disk (tandem disk harrow) and chisel plow (minimum tillage), is common in Iran and widely used by farmers for plowing and preparing the land for rainfed or irrigated wheat production. Determining the most suitable tillage tools for each product, which creates the lowest cost for farmers, can bring more profit to farmers while reducing the investment costs. Many soil chemical and physical properties are influenced by the type of tillage. One of the most important factors, is the soil bulk density or the amount of oxygen in the soil. Oxygen in the soil is one of the most important factors in plant growth and reducing its concentration in the soil affects plant physiological processes. Tillage methods are usually evaluated by the amount of oxygen in the soil and distribution of organic matter. On the other hand using the cropping operations program can significantly affects the amount of oxygen diffusion rate (ODR), fuel consumption and energy efficiency. Prediction of the accurate amount of fuel requirements for tillage operation of the soil is difficult. Changes in humidity, soil type and tillage depth directly effects on the amount of fuel consumption. Therefore, in this study, the effects of three types of tillage implements including moldboard plow (conventional tillage), heavy disk (tandem disk harrow) and chisel plow (minimum tillage), on the amount of power required, fuel consumption, oxygen diffusion rate (ODR) and some soil physical properties including bulk density, and organic carbon contents in a randomized complete block design was studied. The results showed that minimum tillage methods increases the amount of organic matter, reduces fuel consumption and needed less power. Highest fuel consumption of 49.6 liters per hectare and the lowest 21.3 liters per hectare, related to the moldboard plow and heavy disk, respectively. The experimental results showed that in the moldboard plow (MP), the ODR was highest (53.6×10-8 gcm-2min-1) and the lowest (35×10-8 gcm-2min-1), was measured in plowing the field by heavy disk (HD). This value was equal to 42.5×10-8 gcm-2min-1 for chisel plow (CP). Mean values of soil organic carbon related to the moldboard plow (MP), chisel plow (CP) and heavy disk (HD) were 0.38, 0.43 and 0.48 percent, respectively. Effects of tillage methods on the wheat yield were not significant. Mean values of the wheat yield for moldboard plow, chisel plow and heavy disk were 5.45, 5.23 and 5.36 ton/ha, respectively.