Effect of Discs Overlap and Forward Speed on Terradisc Performance in Soil Preparation for Planting Wheat in Corn Residue

Performance of Terradisc stubble cultivator was evaluated in a field experiment during two years in Khuzestan agricultural research center with nine treatments. These treatments were also compared with traditional method. Corn planted in experimental field in summer and wheat cultivated after corn in fall. Terradisc treatments consisted of three levels of forward speed namely: 8, 10, and 12 km/h and three levels of front and rear discs overlaps: 0, 30, and 60 percent. All treatments were replicated three times in this research. The measured and evaluated parameters were fuel consumption, time, effective field capacity, percentage of residue remained on the soil surface, wheat grain yield, and yield components. Two years ANOVA results showed that, tillage method, forward speed, and discs overlap had no significant effect on wheat yield and yield components. Variance analysis of technical parameters showed that effects of forward speed and discs overlap were significant on some of these parameters such as fuel consumption and time requirement. The results showed that amount of residue remained on the soil surface increased significantly, as discs overlap reduced. The highest and lowest remained residue was 88.6 and 64.7 percent in 60 and zero degrees of discs overlap, respectively. Mean weight diameter (MWD) reduced as forward speed increased. MWD calculated 31.6 mm and 33.6 mm in forward speeds of 12 and 8 km/h, respectively. Forward speed of 12 km/h had the minimum fuel consumption (11.8 lit/ha), while the maximum fuel consumption (15.5 lit/ha) belonged to forward speed of 8 km/h. According to obtained results, Terradisc can be recommended as an acceptable option for applying the minimum tillage in corn residue with higher forward speed and lower discs overlap.