Comparative Field Performance Evaluation of Rotavator with L-Shape and C-Shape Blades

Abstract

Rotavators are widely used active tillage implements for seedbed preparation, and the geometry of the working blade is a primary determinant of draft, power demand, fuel economy, and the quality of soil pulverisation and residue incorporation achieved in a single pass. Among commercially available designs, L-shape and C-shape (curved-sweep) blades remain the two most common working tools fitted to tractor-drawn rotavators in South Asian farming systems. This study presents a comparative field evaluation of L-shape and C-shape rotavator blades mounted on a 1.8 m working-width, tractor-operated rotavator and tested at three forward speeds (2.0, 3.0 and 4.0 km/h) at a constant tilling depth of 10 cm in a sandy loam field. The L-shape blade consistently required higher draft force and PTO power (6.1–8.2 kW) than the C-shape blade (4.9–7.1 kW) across speeds of 2.0–4.0 km/h, while also consuming more fuel (2.8–4.5 l/h vs. 2.5–4.0 l/h). However, the L-shape blade produced finer soil pulverisation (mean clod size 10 mm vs. 18 mm at 3.0 km/h), whereas the C-shape blade provided better residue mixing (75% vs. 60% at 4.0 km/h). Thus, the C-shape blade is more energy-efficient (saving 12–15% fuel), while the L-shape blade performs better in soil fragmentation, presenting a clear trade-off between energy use and tillage quality depending on speed. From 2.00 to 4.00 km/h, the reported energy values increased from 58.0 to 66.5 kJ/m³; C-shape blade wear increased from 11.2 to 14.4 mg/ha, while L-shape blade wear increased from 14.4 to 16.0 mg/ha and remained 2.8–3.2 mg/ha higher.