Efficiency of disc harrow adjustment for stubble tillage quality and fuel consumption

Abstract

The compact disc harrow due to post-harvest tillage is used to incorporate the stubble and plant residues into soil, to induce their decomposition and to increase mineralization. The high-cut winter rape stubble is often main challenge of clear disc harrowing, especially in clay loam soil at minimum expenditure of fuel consumption. The aim of this study was to find optimal tillage performances and determine the fuel consumption what required to achieve the preferred level of stubble tillage in loam and clay loam soil after winter oilseed rape harvest. The tillage quality and fuel consumption were investigated in dependence on harrow disc angle (10°, 15° and 20°), tillage depth (5 and 8 cm) and working speed (1.4; 1.9; 2.5; 3.1; 3.6 m∙s−1). The tractor “CASE 135″ was instrumented with data acquisition system and was used to measure fuel consumption, actual working speed and implement draft. Research developed the efficient adjustment of aggregate regime mode to the best soil structure and plant residue incorporation. The beneficial relationship was established by obtaining tillage quality level to fuel consumption, which varied from 2.6 to 5.9 L·ha−1 in depending of soil type (loam and clay loam). Based on research results, the optimal fuel consumption (2.85 L·ha−1) was identified at disk harrow adjustment: disc angle 10°, working speed 3.5 m∙s-1 on both soils, but in different tillage depth 8 cm on loam and 5 cm on clay loam soil.