CHANGE OF WEEDINESS IN A FIVE-FIELD CROP ROTATION BY MINIMIZING THE MAIN TILLAGE OF THE SOIL AND DIFFERENT LEVELS OF FERTILIZER AND ITS IMPACT ON CROP PRODUCTIVITY

This researchwas carried out in a stationary field trial on a typical deep low-humus black soil at the experimental field of Bila Tserkva National Agrarian University. The aim of the research was to assess the productivity of a crop rotation using the main tillage of the soil, which included mouldboard for sunflower (25-27 cm), mouldboardless for corn (25-27 cm) and for soybeans (16-18 cm) and disking for winter wheat, spring barley and white mustard (10-12 cm). The results proved that in this crop rotation the productivity was the highest. Cenotic resistance to weeds was highest in winter wheat and lowest in corn. During the period of the experiment (2012-2021) the potential weediness on unfertilized plots was unchanged and the annual application of 12 tons of manure + N95P82K72 and 16 tons of manure + N112P100K86 per hectare of crop rotation increased this indicator by 2.4 and 6.0%, respectively. The used for the main cultivation of the soil mouldboardless and disking (continuous shallow) causes the spread of rhizomatous and root rhizomes and the localization weeds and an increase the number of seeds of other species in the upper soil layer (0-10 cm). In the weed component of agrophytocenoses of crop rotation the increases of dicot species under mouldboard tillage and monocots - under mouldboardless tillage. Productivity of crop rotation on fertilized and unfertilized plots is almost at the same level for mouldboard and mouldboard & mouldboardless tillage but it is significantly lower for mouldboardless and disking tillage. The highest efficiency in crop rotation provided by differentiated cultivation with used of 12 tons of manure + N95P82K72.