Combined Effect of Disc Coulters and Operational Speeds on Soil Disturbance and Crop Residue Cutting under No-Tillage System in Soil Bin

In the present study, a residue cutting system comprising of different disc coulters (plain, notch, curved teeth, cutter bar and star wheel) was developed and its performance was evaluated under no-tillage system in soil bin. The performance of residue cutting system was evaluated by performing a total of 135 experiments (including replications) in soil bin (black cotton soil, moisture content: 16.8-18.4% db and cone index: 1600 +/- 100 kPa) using forward speeds of 0.56, 0.83 and 1.11 m.s(-1) under the crop residues of rice (8 t.ha(-1)), wheat (8 t.ha(-1)) and maize (16 t.ha(-1)). The effects of disc coulters and operational speeds on performance parameters viz. penetration depth, top width, soil disturbance and residue cutting were investigated. For all type of disc coulters, penetration depth and top width were found in the range of 5-10 and 0.6-5.7 cm, respectively. The least soil disturbance was observed for star wheel disc coulter under maize residue. The operational speeds of 0.56 and 1.11 m.s(-1) favored lesser soil disturbance. The highest mean residue cutting was observed for star wheel disc coulter (98.15%) followed by notched (84.12%), curved teeth (75.82%), plain (61.82%) and cutter bar blade disc coulter (52.12%). The change in forward speed did not produce significant effect on residue cutting. Star wheel disc coulter was effective in cutting of medium to heavy residue loads of rice, wheat and maize crops along with minimal soil disturbance.