Performance Assessment of Disc-Type Furrow Openers in Residue-Retentive Soils under Conservation Tillage

Effective residue management is essential for successful conservation tillage, especially in rice-wheat systems where combine harvesting leaves substantial straw on the surface. This study aimed to compare the performance of two disc-type furrow openers—single disc (SD) and double disc (DD)—in terms of straw-cutting efficiency and draft force under controlled soil bin conditions. Trials were conducted using loamy soil prepared to match field moisture content and compaction. Freshly harvested rice straw was spread uniformly at three densities (1, 2, and 3 t/ha), and the openers were tested at forward speeds of 1.5, 2.0, and 2.5 km/h, maintaining a working depth of 5 cm. The double disc opener consistently outperformed the single disc in cutting efficiency, achieving a maximum of 81.36% at 1.5 km/h forward speed. However, this came with a higher draft requirement, averaging 368.5 N under optimal conditions, the single disc required less draft force but showed reduced cutting performance, particularly at higher speeds and residue levels. Statistical analysis confirmed that furrow opener type, speed, and residue density significantly affected both draft force and straw-cutting efficiency. Overall, the double disc furrow opener was more effective for high-residue conservation tillage, offering a better balance between cutting performance and manageable draft force.