Operational Assessment of Rotary Disc Harrow on Medium Black Soils

Tillage is one of the most critical operations in agriculture, as it directly influences soil structure, seedbed preparation, and crop establishment. This study evaluated the performance of a rotary disc harrow under different field conditions to assess its suitability for soil tillage. Field trials were conducted at the Cattle Breeding Farm and Agronomy Farm of Junagadh Agricultural University, Junagadh (21.5º N, 70.5º E; 107 m a.s.l.), during 2024–2025, with supporting laboratory tests in the Department of Farm Machinery and Power Engineering. The site, located in the South Saurashtra Agro-Climatic Zone of Gujarat, experiences a semi-arid, subtropical climate with an average annual rainfall of 860 mm, and the soil is clayey in texture with a moderately sub-angular blocky structure. Key performance indicators, including effective field capacity (EFC), field efficiency (FE), fuel consumption, wheel slip, and clod mean mass diameter (MMD) were measured. The harrow recorded a maximum EFC of 0.364 ha h⁻¹ and FE of 76%, with fuel consumption of 4.2 L h⁻¹ and wheel slip of 3.5%. Soil pulverisation, expressed as clod MMD, ranged from 9.62 to 11.30 cm at operating speeds of 2.0–2.5 and 3.0–3.5 km h⁻¹, respectively. The findings confirm that the rotary disc harrow is effective for tillage in clayey soils under semi-arid conditions and provide practical insights for improving implement performance and soil management.