Influence of Heat Stress and Water Availability on Productivity of Silage Maize (Zea mays L.) under Different Tillage and Fertilizer Management Practices in Rostov Region of Russia

The aridization of the climate negatively affects the growth and development of plants and their productivity. The aim of this study was to determine the effect of heat stress and water availability on maize for silage under aridization and to find out the effectiveness of technological methods to maximize the use of available moisture. A long-term multifactorial experiment was performed during the period 1991–2020 in the region south of Rostov, Russia. The long-term multifactorial experiment is located in a zone of high heat supply and insufficient moisture, so the latter factor limits the yield of corn and dictates the need to find solutions to increase its environmental sustainability in extreme weather conditions. The values of the hydrothermal coefficient (HTC) were determined for the period of maize cultivation for each year of the study, ranked in ascending order and grouped into clusters. The results were mathematically processed by calculating the mean values (M) and their standard deviations (±SEM) with Statistica 13.3 software. The optimum conditions for silage maize development were found under the combination of 265 mm of rainfall and a 19.8 °C average temperature during the growing season. The maximum yield of silage maize was 33.8–45.2 t ha⁻¹. In dry years (HTC = 0.3), tillage had an advantage: the yield increase was 0.2–1.6 t ha⁻¹. In wet years, moldboard tillage was preferable: the yield increase was 0.3–2.9 t ha⁻¹. The application of farmyard manure for fertilization increased the yield by 10.5–41.9%. Increasing the fertilizer rate by 1.5 times increased the yield by 21.0–59.8%. In drought, tillage and average fertilizer rate provided returns by increasing yields up to 7.7 kg/kg. Our study provides valuable recommendations in fodder production, promotes moisture conservation, preserves soil fertility on the slopes when cultivating corn for silage, and will be useful to specialists in improving the efficiency of agricultural production.