Научный журнал

The studies assessed the effectiveness of mineral fertilizers and the biological product V417 by the aftereffect of green manure (oil radish) during plowing, disking and chiseling on the content of mobile potassium in the arable (0-25 cm) layer of chernozem typical medium-thick medium-humus heavy loamy, underlain by pebbles and the yield of spring oats. Initial indicators when starting the experiment: the content of humus in the arable soil layer (according to Tyurin) is 4.2%, mobile phosphorus and potassium (according to Machigin) is 15 and 233 mg/kg, the reaction of the soil environment is neutral (pHKCl 7.1), uneven depth of pebble (50-100 cm). The crops of spring oats (variety Konkur) were placed according to the predecessor corn in a four-field grain-row crop rotation of peas – winter wheat – corn for grain – oats. During the research, on average over 2 years, a decrease in the content of mobile potassium was observed in the variant without fertilizers, biological preparations and green manure for all soil cultivation methods. The greatest decrease - by 34 mg or 14.5% relative to the initial content of 233 mg/kg was noted during plowing and the supply of soil with mobile potassium in this option moved from the supply group with an average potassium content to the group with a low content (199 mg/kg of soil) according to the Machigin method. During disking and chiseling, the initial average level of soil supply with mobile potassium is maintained, despite a slight decrease in its quantity. The application of mineral fertilizers, a biological product and their combined use against the background of the aftereffect of green manure made it possible to increase the amount of mobile potassium and the yield of oats during plowing by 23-44 mg/kg and 0.2- 1.0 t/ha, and when disking - by 20-76 mg /kg and 0.38-1.29 t/ha, with chiseling - by 27-63 mg/kg and 0.48-1.19 t/ha, respectively. The greatest increase in the content of mobile potassium - 76 mg/kg (up to 275 mg/kg) and oat yield - 1.29 t/ha (up to 2.64 t/ha) was achieved in the variant with the combined application of N80P60K60 and a biological product for the aftereffect of green manure against the background disking, although the increase was within the level of the initial average provision according to the Machigin method. The values of the potassium balance and its intensity for all soil treatments increased from negative in variants without fertilizers (˗24-32 kg/ha with an intensity of 40-47%), when using chemicalization and biologization means, increased to 76-101 kg/ha and an intensity of 212- 235%. The highest potassium balance - 101 kg/ha and its intensity of 235% was noted during disking in the variant with the combined application of mineral fertilizer and a biological product for the aftereffect of green manure.