||One of the main problems in the agriculture of Ukraine is soil recompaction, which is often observed in the lower horizons of the arable layer and badly affected the access of the plant to the moisture, air, heat and nutrition.
Only scientifically grounded soil tillage system can regulate and maintain an optimal density of the arable layer.
The purpose of our investigation was to determine the dynamics of changes in the agro – physical indicators of black earth in peas crops in the conditions of organic agriculture in the Southern Steppe of Ukraine by different methods of basic tillage. And also to identify the main factors which affect the agro-physical indicators.
The results of the field researches that were conducted during 2015–2017 in the graincultivated four – field crop rotation with following crops changes: peas – winter wheat – winter barley - ½ sunflower + ½ corn, show the influence of the soil tillage system on the agrophysical properties of the soil, its structure coefficient and density, were outlined.
It was established that in the southern steppe of Ukraine the intensity and depth of the soil tillage for peas crops on the black earth led to the slight improvement of its structure. The highest index of the structure at the end of vegetation was in the version with the boardless plowing to the depth of 14 –16 cm and was 2,69. This indicator was not significantly smaller on the background of plowing – 2,68, but the smallest it was in the version with boardless plowing to the depth 10–12 cm – 2,57.
The contents of agronomically valuable aggregates, in the phase of peas' growth, in the size of 10 to 0,25 mm in the arable layer, was 75,7 % on the background of plowing, 76,3 % on the background of boardless plowing to the depth of 14–16 cm and 79,7 %.on the background of boardless plowing to the depth of 10–12 cm.
Also, in our investigation we revealed the depth reducing of arable layer of soil in general and by layer in the version with moldboard plowing compared to boardless plowing to the depth of 14–16 cm and boardless plowing to the depth of 10–12 cm at the beginning of peas vegetation. Depending on the soil tillage, despite the changes in its density, this indicator was within optimum limits in all the variants.