Yield of winter wheat depending on preceding crops in the right-bank forest-steppe of Ukrain

Abstract
The realities of the current state of Ukraine's economy show that the share of agricultural production in its structure is 15-18 %, and in the case of state support, may increase to 25 %. The main task of agricultural production is food security of the state, and the successful solution of this problem largely depends on the level and rate of growth of grain farming. Due to its high nutritional value, winter wheat occupies a leading place among the most important grain crops. In world agriculture, it is one of the three strategically important agro-food crops (wheat, rice, corn). Therefore, world food security depends on the state of development of wheat production. The potential of modern adaptive technologies for growing winter wheat is 30-50% increase in its yield from the current level. However, the main obstacle to the growth of wheat production may be climate change, which results in deteriorating moisture supply. Given that moisture reserves determine the agrochemical, agrophysical and biological properties of the soil, ensure the growth and development of plants, as well as the formation of elements of the crop structure. One of the determining factors in the formation of the water regime of the soil in winter wheat crops is the optimization of its placement in crop rotation after different preceding crops. The urgency of this issue has led to the choice of research. The article presents the peculiarities of the formation of available moisture reserves for the cultivation of winter wheat, depending on the preceding crops. It was found that in the Right-Bank Forest-Steppe in terms of the ability to provide winter wheat for the sowing period (0-10 cm layer of soil) with available moisture, the preceding crops were placed as follows: winter rape-sunflower-soybean-corn for silage. At the time of sowing, sufficient moisture reserves in the 0-10 cm layer of soil were formed by placing winter wheat after peas and winter rape, respectively 11,5 and 10,9 mm. The highest yield of winter wheat on average in 2019-2021 at the level of 5,68 t/ha was ensured by its placement after peas. The use as a precursor of winter rape and soybeans reduced its yield by 4,40 and 5,40 %, respectively, which in absolute terms was 0,25 and 0,31 t/ha. After maize for silage and sunflower, crop yields decreased by 0,48 and 0,67 t/ha, respectively. The highest quality indicators of winter wheat grain - protein content of 13,1 and 13,3 % and gluten 25,2 and 25,5 % were obtained for its placement after legumes (peas and soybeans). Winter rape, as a preceding crops, provided grain quality indicators at the level of 13,0 % protein and 24,5 % gluten. When placed after sunflower and corn in silage, the protein content was 12,6 and 12,8%, and gluten – 24,0 and 24,1 %, respectively.