FORMATION OF PHOTOSYNTHETIC PRODUCTIVITY OF CORN CROP UNDER A BIOLOGIZED NUTRITION SYSTEM

Photosynthesis is the basis of plant life, and therefore scientific research into the structure of the photosynthetic apparatus and the mechanisms of its functioning and regulation is of paramount importance for increasing the productivity of agricultural crops, including corn. This process is unique due to its ability to synthesize organic matter using and storing light energy. This article presents the results of studying the effect of the combined use of soil biofertilizer based on phosphorus and potassium mobilizing bacteria and different rates of mineral fertilizers on the formation of leaf surface area and photosynthetic potential of crops of the studied corn hybrids of foreign selection at different plant density. Field experiments were conducted during 2021 - 2023 in the conditions of the Agronomichne Scientific Research Farm of the Ukrainian Academy of Agricultural Sciences, the soil of the experimental field is gray forest medium loam. According to the results of the conducted research and the processing of the obtained data, it was established that the application of the biological fertilizer Groundfix in pre-sowing cultivation at a rate of 4 l/ha, against the background of complete mineral fertilizer (N120P60K60), ensured an increase in the leaf surface area by 7.5 - 9.6% or 2.8 - 3.9 thousand m2/ha compared to the control, depending on the hybrid and plant density, and when Groundfix was applied at a rate of 6 l/ha, the leaf surface area was 9.2 - 10.9% or 3.6 - 4.4 thousand m2/ha greater than in the control. The results of our research on the features of the formation of photosynthetic potential confirmed the positive impact of optimizing the corn fertilization system through the use of the biological fertilizer Groundfix. A regular increase in photosynthetic potential was found in the comparison of interphase periods from 12 leaves to wax ripeness. In the variants of the experiment where the rates of mineral fertilizers were reduced from N120P60K60 to N80P40K40, the level of photosynthetic potential of crops was also lower, on average by 13.8 - 15.6%.