Variability of corn grain yield and moisture depending on the method of tillage

Optimisation of corn grain production requires a comprehensive approach to reducing technology costs. The purpose of the experiment and the research objective was to determine the optimal method and depth of primary soil tillage to reduce soil moisture losses and to substantiate the appropriate maturity group of the cultivated hybrids for the implementation of their genetic yield potential with maximum moisture release under field conditions of the central Forest-Steppe zone. The response of 11 mid-early and mid-season corn hybrids (FAO 210-350) was evaluated in 2019-2021 under different primary tillage methods – disc harrowing (up to 15 cm), ploughing (25-27 cm), and deep loosening (35-37 cm) – and yields and moisture release were compared across treatments and hybrid maturity groups. A statistically high correlation coefficient (r=0.74***) indicated the dependence of corn grain yield on the depth of the main tillage. Loosening at 35-37 cm provided an increase in the yield of corn grain from 0.7 to 1.6 t/ha compared to ploughing, and disc harrowing reduced the yield from -0.3 t/ha to -0.9* t/ha. The yield regression equation from the ripeness group (FAO) – y=3.5269+0.0117x – indicated the possibility of increasing grain yield when using hybrids with a longer growing season, which was confirmed by a significant positive correlation coefficient r=+0.86*** (73.96%). Statistically significant correlation of these features with double disc harrowing – r=+0.42** (17.6%), with ploughing – r=+0.22** (4.8%), with deep loosening – r=+0.38**(14.4%), respectively. The trend of increasing grain moisture with increasing yield was established – r=+0.89*** in the hybrids under study, regardless of the method of tillage. Increasing the yield of corn grain was possible by growing later-maturing hybrids, while the moisture content of grain will also increase. The highest grain yield was provided by mid-season hybrids with Tesla (FAO 350) – 8.95 t/ha (+1.03*t/ha) and KWS 351 (FAO 350) – 8.77 t/ha (+1.6**t/ha) against the background of deep loosening of the soil at 35-37 cm with an average humidity of 16.81% and 16.28%, respectively. As a result of the experiment, it was recommended to sow in the central Forest-Steppe with mid-season corn hybrids (FAO 300-350) using deep loosening of the soil with a disc-chisel unit up to 35-37 cm as the main treatment