|Riassunto in Inglese:|
Traditional soil tillage based on medium depth ploughing can determine excessive energy costs, loss of nutrients, decrease of natural fertility and, in some cases, increase of soil erosion caused by wind and water. These negative effects can be reduced by introducing soil tillage methods, such as tilling without inversion of layers and minimum tillage, which aim at maintaining a permanent soil cover and at reducing number and depth of interventions. There are many types of equipment on the market with large work front, formed by assembling various implements in order to fulfill different agronomic functions. The effectiveness of such equipments essentially depends on the texture of the soil and on the amounts of surface weed biomass or crop residues. These can lead to ground accumulation between the tools, especially on heavy clay soil, to reduced working speed and to decreased uniformity of residue mixing and burial across the whole working width.
The Agricultural Machinery Testing Centre of CRA-ING (CPMA), accredited as Testing Laboratory (ACCREDIA no. 1141) in accordance with the requirements of the EN ISO/IEC 17025:2005 standard, performed tests to evaluate the operative performances of an innovative combined cultivator, allowing the contemporary execution of deep tillage and soil refining, in comparison with a three furrows, reversible mouldboard plough, for traditional soil primary tillage, and an offset disk harrow, for minimum tillage of untilled soil. The tests were carried out on a flat, silt-clay untilled soil, using a 205 kW instrumented tractor. The objective of this study was to evaluate the energy parameters of each tractor-machine coupling and the quality of their work, especially with reference to the capability of burying biomass residues as a function of working depth and speed. The tests results show a decrease of power and energy requirements proceeding from traditional (thesis A) to more conservative tillage methods (thesis C), that can be synthesized by savings up to 37.6% for the fuel consumption per hour and up to 83.6% for the fuel consumption for surface unit. Intermediate values have been obtained for the combined machine (thesis B). The best performances on biomass burying were provided by the plough and the cultivator.