Productivity of Alfalfa of Various Slopes for Seeds, Depending on Bio- and Biotic Factors

Abstract

The scientific paper presents the results of studies of the influence of mowing on the development and formation of alfalfa seed yield when growing it on chernozems of the southern steppe of Ukraine on non-irrigated lands. Studies aimed at identifying factors that can contribute to increasing alfalfa seed productivity and improving soil fertility, reducing the pesticide load on them, are relevant. The aim of the work was to determine the influence of abiotic and biotic environmental factors (weather conditions and mowing on seeds, relationships between weeds and cultivated plants, population of agrophytocenoses with pests) on alfalfa seed productivity. It is determined that at the first mowing in the agrophytocenosis there are, on average, 12.5 specimens./ m2 of weeds that during the growing season of alfalfa seeds of the third year of life remove 40.8 kg/ha of nitrogen, 3.5 – phosphorus, 41.3 – potassium and 9.9 kg/ha of nitrogen from the soil. calcium, and with an intermediate slope, the density of weeds is much less (9 PCs./m2), which absorb almost 3 times less nutrients from the soil. It was found that the cultivation of alfalfa with intermediate mowing (mowing the first for green fodder at the beginning of budding) contributes to an increase in seed yield by 20.9% compared to the first, the level of profitability increases from 182.9 to 313.7%, or by 130.8 percentage points (71.5 percent. So, growing alfalfa for seeds with intermediate mowing is environmentally safer, due to a decrease in the number of pests in the agrophytocenosis, and therefore the need for insecticides, compared to the first mowing, which is proposed for introduction into production.