Performance Evaluation of Vertical Discs and Disc Coulters for Conservation Tillage in an Intensive Rice–Wheat Rotation System

Abstract

As an advanced agricultural production technology, conservation tillage has been developed rapidly and adopted widely for many crops all over the world, but challenges remain with regard to dealing with excessive residues, especially for intensive rice–wheat rotation systems. Most studies to date have been based on a single type of tool and the indoor bin test to explore its performance. Accurate field test data on the tillage performance of different types of tools for conservation tillage are lacking in this area. In this study, five tillage tools were tested in a paddy field with plenty of crop residues to compare their performance. They were three vertical discs with plain disc (PD), notched disc (ND), and rippled disc (RD) and two disc coulters with plain disc coulter (PDC) and notched disc coulter (NDC). All five tools were tested using a specific field test rig at two different working depths of 70 and 100 mm. Tillage forces, straw cutting efficiency, soil disturbance width, and soil cutting depth were measured. The results showed that tool geometry and working depth had a significant impact on tillage performance. The vertical disc performed a higher average straw cutting efficiency, as well as lower tillage forces and lower soil disturbance width than the disc coulter. For straw handling and furrowing operations, RD had the highest straw cutting efficiency, moderate tillage force, and appropriate soil disturbance width among the five tools. For all five tools, the 100 mm working depth results in 40% higher draught force, 39% greater vertical force, and 18% higher straw cutting efficiency on average. For no-tillage seeding in the intensive rice–wheat rotation system, the RD would be a more suitable rotary tool for conservation tillage practice.