Effects of six primary tillage implements on energy inputs and residue cover in Central Italy

The use of agricultural machinery represents the main aspect contributing to the total energy input in the agricultural system. The study evaluated the energy requirements and the work quality of two conventional (threefurrow plough and spading machine) and of four conservation implements (rotary harrow, subsoiler, disk harrow, combined cultivator) for mediumdeep primary tillage in a silty-clay soil, widespread in Central Italy. The tests were carried out with the aim of selecting the most energy-efficient implement. Working speed, force of traction, fuel consumption and energy demands were measured, using a 205 kW instrumented tractor. Cloddiness and roughness of the tilled soil, biomass coverage index and burying degree were evaluated. The conservation tillage implements gave the best results in fuel consumption and energy requirements respect to the conventional implements, with energy savings up to 86% in the case of disk harrow. The rotary harrow showed intermediate values and the best soil refinement. Among the conservation implements, the disk harrow showed the best performance on biomass coverage index (43.8%), while the combined cultivator showed the highest value of biomass burying (87.8%) and the best performance on fuel consumption per hour (25.8 kg h–1).