SOIL STRUCTURE AND HARDNESS CHANGE RESULTING FROM THE DEPTH OF A TRACTOR TRACK UNDER DIFFERENT WHEEL DRIVE TOWING STRENGTH

The aim of the research is to reduce the influence of wheel propellers on the structure and hardness of the soil in the track of the tractor. The technique and results of the study of the impact of the drive wheels of the power tool of the machine-tractor unit (MTA) on the structure and hardness of the soil in the layers of the horizon are presented. The influence of slipping on these indicators is revealed. The research has been of MTA consisting of a tractor of drawbar category 0,6 kN (T-25A) and trailed cultivator KPS-4,0. The method of investigation involved the determination of changes in the structural composition of the soil (DS parameter,%) by the number of erosion-hazardous (less than 0.25 mm in size) particles, as well as soil hardness (DN parameter, kg/cm2) on the track of the tractor in different layers of the horizon (0...50 mm; 50...100 mm; 100...150 mm; 150...200 mm and 200...250 mm). The slipping mode was changed by changing the number of working sections of the cultivator. The slipping of the driving wheels was taken into account, as well as the agronomic background. The studies were carried out in conditions of equal humidity. The speed of MTA, its weight and the air pressure in the tires of the drive wheels is maintained constant. It is established that the greatest change in the structure of the soil on the layers of the horizon is exposed when slipping δ=20...30%. To change the hardness of this range is also the least favorable. The obtained dependences of the structure and hardness of the soil on the layers of the horizon from slipping allow us to recognize the rational modes of MTA work, in which the slipping of the propelling power means is in the range of 9 to 12% regardless of from the soil fertility. Slipping over 12% leads to a sharp increase in the soil structure of the number of erosion-hazardous particles, as well as an increase in the hardness of the soil in the track of the tractor in 3,4 ... 3,7 times in the layer depth of 50 ... 100 mm.