Energy Consumption Studies of Soil-Protecting Machine-Tractor Aggregate for Soil Loosening

Abstract Over the years, soil loosening, as a primary form of soil tillage, has been performed with machines of various construction characteristics that usually work at a depth of 0.40 m or sometimes even greater depths. These machines include cultivators for soil loosening, machines for deep soil loosening, and subsoilers. In Bulgaria, the Maschio-Gaspardo subsoiler, model Artiglio 300/7, has been successfully used for three years to perform this technological operation. This machine is aggregated with tractors with a nominal towing capacity of 50 kN, such as John Deere 8R280 tractors. The efficient use of this machine-tractor aggregate required a thorough energy-consumption study using the tensiometer method. The paper presents the study findings, which show that the tractor chosen for this newly formed aggregate is suitable due to its towing and power capacity. Its maximum towing resistance when performing soil loosening reaches 36.40 kN, while the normal indicator for this tractor is 50.00 kN. The maximum power consumption can reach up to 208.78 kW, with an engine load factor of 92.01% and a permissible wheelspin of a maximum of 14.9%. This machine-tractor aggregate is properly sized in terms of power consumption and ensures optimum towing and speed operation when carrying out the soil conservation method of soil loosening as main tillage on agricultural land with calcic chernozem soil.