CORN FOR GRAIN IN CONTINUOUS GROWING UNDER DIFFERENT FERTILIZER SYSTEMS AND WEATHER CONDITIONS

Abstract

On the experimental field of the Poltava State Agricultural Experimental Station named after M. I. Vavilov of the The Institute of Pig Breeding and Agro-Industrial Production of the National Academy of Agrarian Sciences of Ukraine, during 1984-2023, on typical chernozem in conditions of unstable moisture of the Left-Bank Forest-Steppe, were conducted researches to study the continuous growing of corn for grain and its productivity. Precipitation is the leading factor in providing corn with available moisture in this region. Different hydrothermal conditions, especially the amount of moisture during the agricultural year and the vegetation, led to sharp fluctuations in grain yield over the years, which occurred in a wide range. The analysis of the average values ​​of corn productivity for each 10 consecutive years of conducting these studies made it possible to establish that during the first decade of observations, the dynamics of this indicator in subsequent periods took place in the paradigm of its growth, albeit at a different level. Maize grain yield and its correlation with different weather conditions and fertilization systems, regardless of the replacement of maize hybrids, ranged from direct to inverse and from low to high. Long-term application of different doses and ratios of organic and mineral fertilizers contributed to changes in both quantitative and qualitative indicators of humus in the soil. It was determined that the content of total carbon in the fertilized areas was higher by 3,0 and 3,3 relative percent compared to the unfertilized ones. Special attention was paid to the ratio between humic and fulvic acids, which directly depends on the fertilization system. The different effect of this agrotechnical measure on the amount of humus accumulation in the soil is shown. Thus, in areas without fertilizers (control), its accumulation occurs at the level of an average indicator and a weak effect of organic acids on the mineral part of the soil, while under the organo-mineral fertilization system, this process takes place intensively, and the mineral part remains almost unchanged.