YIELD AND BALANCE OF NUTRITIONAL ELEMENTS IN WINTER GRAIN CROPS DEPENDING ON SOWING PERIOD IN THE SOUTHERN STEPPE OF UKRAINE

Abstract

One of the factors of soil formation is the plant world, which accumulates organic matter through the process of photosynthesis. Organic matter is transformed into humus, which is the main dominant of the soil. In addition to humus, organic matter provides the accumulation of macronutrients such as nitrogen, phosphorus and potassium. The first priority is to create the optimal content of essential nutrients and humus in soils, along with the development of methods to improve the efficiency of fertilizer application. Organic production should not be primitive or extensive. On the contrary, crop production must be sustainable and highly productive. Soil fertility must be restored. The dominant soil is humus. Its quantity is the first criterion for the formation of crop yields, including cereals. Humus is restored at the expense of organic matter through a complex transformation. The aim of the research was to establish the change in soil fertility and the yield of winter wheat and winter barley, depending on the timing of sowing in the conditions of organic farming in the Southern Steppe of Ukraine. Research methods. Field experiments were carried out on the territory of the Odessa State Agricultural Experimental Station of the National Academy of Agrarian Sciences of Ukraine. The experiment studied the effect of sowing dates on the productivity of winter wheat and barley varieties, as well as the renewal of soil fertility and the balance of basic plant nutrients. The total area of the experiment is 4617 m2; the accounting plot is 16.5 m2. Varieties of winter wheat and barley were sown in 10 days interval - from September 25 to October 25. The predecessor is fallow. Placement of variants and repetitions – by the method of the Latin rectangle. Sowing was carried out with a selective planter "Klen – 1.5 C". Repetition – three times. Harvesting was carried out in an inseparable way using the "Sampo – 500" combine. A high yield has a positive effect on the supply of fresh organic matter, that is, there is not only a direct relationship between fertility and yield, but also an inverse relationship: a high yield through plant residues affects soil fertility. As you can see, the larger the yield, the more by-products are formed and the more plant mass accumulates. Winter barley compared with winter wheat has almost the same humus balance. Findings. According to the results of the studies, the best sowing time for all criteria that ensure the formation of grain crop yields and expanded reproduction of soil fertility – Southern chernozem, in terms of humus, nitrogen and potassium content, as well as simple reproduction of phosphorus content, is the second sowing date (October 5).