Dolia S. Efficiency of tillage methods during the corn growing in the Left-Bank Forest-Steppe of Ukraine

For the first time: under conditions of unstable and insufficient moisture on typical black soils, the expediency of using the PRN-31000 moldboardless tillage at a depth of 33–35 cm for growing corn for grain has been substantiated; The impact of local tillage with chisel tools on agrophysical, water-physical and microbiological soil parameters was studied; the dependence of soil surface condition and resistance of corn agrocenosis to erosion processes on the background of minimal tillage was determined; on the corn hybridisation sites of DB Khotyn, it is recommended to plough to a depth of 25–27 cm in combination with the complex application of a soil herbicide based on the active ingredient propizochlor 720 g/l and insurance herbicides with the active ingredients clopyralid 300 g/l + tifensulfuron-methyl 750 g/kg. Improved: distinct technological processes of corn growing at hybridisation sites aimed at increasing yields and quality of seed material. Further development was made in the study of the impact of basic tillage methods for growing grain corn in the Left-Bank Forest-Steppe of Ukraine. The aim of the research is to determine the effectiveness of different methods of basic soil tillage for corn growing in the conditions of the Left-Bank Forest-Steppe of Ukraine. To achieve this goal, the following tasks were envisaged: to investigate changes in the agrophysical state of the tilth layer depending on the degree of intensity and depth of tillage; to determine the impact of different methods of basic tillage on the provision of moisture to the root layer of the soil; to investigate the cellulosolytic activity of the soil depending on the methods of basic tillage; determine the level of soil protection efficiency of different methods of basic tillage; to investigate the impact of primary tillage methods on herbological changes and phytosanitary conditions in corn crops; to investigate the impact of different methods of basic tillage on maize hybridisation plots at the DB Khotyn against the background of integrated use of soil and insurance herbicides; to determine the level of corn grain yield and the effectiveness of basic tillage methods; to give an economic and energy assessment of growing the corn hybrid DB Khotyn under different methods of soil tillage. The dissertation was carried out within of the initiative theme of the farming and herbology named after O.M. Mozheiko chair in the period 2021–2023 «Developing the theoretical foundations of a soil protection system of farming in the Left-Bank Forest-Steppe and Northern Steppe of Ukraine» (state registration number 0121U108245), as well as the economic contractual topic with LLC «MAYAK VVV» (research and development work № 8-24 D), which was carried out under the research programme of the Ministry investigative project № 2-24-26 BO of 12 January 2024 «Development of measures to ensure the sustainable productivity of agrophytocenoses under the influence of abiotic and biotic stress factors». To solve the tasks, the following methods of basic tillage were investigated: ploughing PLN-4-35 to a depth of 25–27 cm; chisel local tillage PC-2.5 to a depth of 33–35 cm; moldboardless tillage PRN 31000 to 33–35 cm and discing BDM-2.5 to 10–12 cm. The yield of the maternal form of the corn hybrid DB Khotyn on the hybridization sites was determined. Herbicide protection systems based on active substances were investigated: nicosulfuron 45 g/l; 2,4 D-ethylhexyl ether 452 g/l + florosulam 6.25 g/l; acetochlor 900 g/l; clopyralid 300 g/l + thifensulfuron-methyl 750 g/kg and propizochlor 720 g/l; clopyralid 300 g/l + thifensulfuron-methyl 750 g/kg. It has been established that replacing ploughing with deep moldboardless or shallow discing leads to an increase in the values of certain agrophysical indicators of soil fertility. The soil hardness showed similar trends to the density of the compaction, and the correlation between these indicators was 0.99. All the variants studied provided good structure of the 0–30 cm soil layer, with higher values in the case of moldboardless and chisel tillage. In terms of the impact on the water-physical parameters of the soil, the studied tillage did not have a significant difference, but chisel tillage created conditions for greater moisture accumulation in the arable layer, and moldboardless tillage in the layer of 0–100 cm: 855 and 3090 m3/ha. The high cellulosolytic activity of the 0–30 cm soil layer after ploughing to a depth of 25–27 cm was found. Ploughing as the main tillage method provided the conditions for a high yield of corn grain. In this variant, it was 6.70 t/ha, and the productivity was 7.04 t of feed protein units/ha. The research of the seed yield of the corn hybrid DB Khotyn in the hybridisation plots showed that the arrangement of rows of mother plants according to the 2:6 scheme is the most effective, in particular at a distance of 1.4 m from the father plants.