THE EFFECT OF HERBICIDES AND MINERAL FERTILIZERS ON THE YIELD AND QUALITY OF WINTER WHEAT GRAIN IN THE STEPPE ZONE OF THE REPUBLIC OF NORTH OSSETIA – ALANIA

Abstract

In winter wheat crops, the fight against weeds, together with the use of mineral fertilizers, which increase the yield and quality of the crop by reducing the removal of nutrients from the soil, is an urgent production task. The purpose of the research is to develop methods for increasing the yield of winter wheat with the combined use of herbicides and mineral fertilizers. Field experiments were carried out in the steppe zone of the Republic of North Ossetia – Alania in 2017–2019. The soil of the plot is chestnut calcareous. Weather conditions during the years of the research were favorable. The object of research is the high-yielding winter wheat variety Utrish. Mineral fertilizers stimulate the vital activity of soil microorganisms and enhance the cycle of biological transformation of plant nutrients, and herbicides have an inhibitory effect on cellulose-decomposing microorganisms, which ultimately reduces the rate of cellulose decomposition. Cellulose decomposed most intensively on backgrounds where mineral fertilizers were used. In control variant 3, the determination period, cellulose decomposed by 29.8%, against an average background (N60P60K60) by 40.2%, and against an increased background (N90P90K90) – 43.6%. Herbicide Grench at a dose of 10 g/ha on backgrounds without fertilizers and with fertilizers in different doses ensured the death of weeds during the growing season by 76.6 ... 89.2%. The herbicide Luvaram (1.6 l/ha) also provided high weed death – 56.4–62.6%. The application of a tank mixture (Grench 5 g/ha + Luvaram 0.8 l/ha) reduced weed infestation of winter wheat crops by 85.3–89.2% on different backgrounds of fertilization. The highest yield and profitability in the experiment were noted in the variant of the combined use of mineral fertilizers and herbicides. The level of profitability against the background of medium doses of mineral fertilizers (N60P60K60) was 130–150%, and against an increased background (N90P90K90) – 149–169%.