|Riassunto in Inglese:|
Mouldboard ploughs represent the most diffused implements in the soil main tillage, for the positive effects determined by the vertical soil cutting and, most of all, by the cut slice overturning. Modern reversible mouldboard ploughs, equipped with electro-hydraulic control systems, can be rapidly adjusted according to the requirements of specific tillage conditions, reducing the time and the discomfort for the adjustment and to optimize the working width. This paper reports the results of tests aimed at evaluating and comparing the dynamic-energetic parameters and the quality of the work determined by the use of a three furrow, reversible mouldboard plough, according to four different configurations obtained by means of the control system, allowing the implement to work as a traditional in-furrow plough or as an out-of-furrow plough and to continuously vary the working width. The tests have been carried out on silt-clay, untilled soil. The dynamic-energetic parameters have been measured by means of a mobile laboratory based on a tractor equipped with sensors and radio-transmitting the signals to a pc lodged on a van. Ploughing at the maximum width, both in in-furrow and out-of-furrow, showed higher instant power requirements and fuel consumption, as the energy required for surface unit resulted lower than for ploughing at minimum width. Out-of-furrow ploughing seemed to favourite the energy saving with respect to the traditional ploughing. As to the quality of work, the refinement index, based on the determination of the cloddiness, resulted lower under maximum working width conditions both in in-furrow and out-of-furrow ploughing, as the differences between these ploughing modes do not seem significant.