Miroshnichenko M. Productivity of short crop rotations and soil fertility depending on the cultivation methods and fertilization in the Left Bank Forest-Steppe of Ukraine

Scientific novelty of the obtained results. For the first time for the zone of insufficient moisture of the Left Bank Forest-Steppe of Ukraine the efficiency of organic-mineral systems of fertilizers and tillage in short crop rotations is substantiated. It was proved the high efficiency of alternative fertilizer systems with the application of by-products, the advantage of crop rotation and different depths of plowing, which ensured the reproduction of natural soil fertility. It was improved the system of soil tillage and fertilization in short crop rotations for the zone of insufficient moisture of the Left-Bank Forest-Steppe of Ukraine. It was further developed the issues of the influence of crop rotation structure, soil tillage and fertilization on the formation of natural soil fertility, water and nutrient regimes, phytosanitary condition of crops, energy efficiency of agricultural technologies. The practical significance of the obtained results. Based on the results of long-term field research, agrochemical and agrotechnical principles of sustainable cultivation of agricultural crops in short crop rotations of the Left-Bank Forest- 11 Steppe of Ukraine have been formed, which ensures reproduction of fertility of typical weakly saline chernozem and increase the productivity of crop rotation. The research results were implemented at the Veselopodilska Research-Breeding Station, Semenivskyi District, Poltava Region on an area of 60 hectares. The application of N46,2P33,7K33,7 + by-products in grass crop rotation and multi-depth plowing ensured crop rotation productivity at the level of 8.0 fodder units, grain yield - 2.20 t/ha, with receiving additional products from one hectare in the amount of 1,830 thousand UAH. The main results of research. It is established that in the grain-steam crop rotation in sugar beet crops the highest reserves of productive moisture in 1.5 m of soil layer were formed by applying 6.25 t/ha of manure + N33.7P33.7K33.7 + by-products and carrying out various-depth plowing – 226 mm, in winter wheat and spring barley crops – for combined tillage of soil on the background of the aftereffect of an alternative fertilizer system – respectively 232 and 251 mm. It was investigated that the application of 6.25 t/ha of manure + N33.7P33.7K33.7 + by-products in the conditions of grass crop rotation on the background of different depth plowing provided the best conditions for expanded reproduction of natural soil fertility. At the end of the 10th rotation, the humus content in the arable 0-30 cm layer of grass crop rotation increased to the beginning of rotation by 0.28% with absolut value of 4.81% and prevailed the humus content in the grain-steam crop rotation by 0.18%. Plowing of by-products against the background of N46.2P33.7K33.7 + by-products stabilized the humus content in crop rotation at 4.79%. It was determined that the use of organo-mineral fertilizer systems in both crop rotations for 40 years increased the content of mobile phosphates in the arable 0-30 cm layer in 2.5 times compared to the beginning of rotation, with the advantages of grass crop rotation to grain-row crops rotation per 5 mg/kg of soil. With the application of 6.25 t/ha of manure + N33.7P33.7K33.7 + by-products in both crop rotations the highest content of mobile potassium in the soil was achieved – 138-140 mg/kg, which exceeded the beginning of rotation by 30 mg/kg of soil. 12 According to the results of research it is established that the best conditions of mineral nutrition of sugar beet were formed in gras crop rotation with an application of 6.25 t/ha of manure + N33.7P33.7K33.7 + by-products and plowing of different depths. This fertilizer system provided the highest content of mineral nitrogen, mobile phosphorus and potassium in the 0-30 cm layer of soil at the beginning of the growing season – 27.5, 58 and 163 mg/kg of soil, respectively. It was investigated that in winter wheat crops the smallest abundance of weeds was observed for the application of 6.25 t/ha of manure + N33.7P33.7K33.7 + by-products: for combined tillage – 20.8, plowing of different depths – 23.7 pcs./m2. In sugar beet crops, the lowest abundance of weeds in both crop rotations was achieved by plowing at different depths and applying 6.25 t/ha of manure + N33.7P33.7K33.7 – 16.7 pcs./m2. In spring barley crops, the least abundance of weeds was provided by the afte