NUTRIENT REGIME AND WEED INFESTATION OF GRAIN SORGHUM CROPS UNDER DIFFERENT METHODS OF MAIN SOIL TILLAGE AND FERTILIZATION

The article presents the results of experimental studies on the influence of different methods and depths of primary tillage, as well as nitrogen fertilizer rates, on the nutrient regime and weed infestation of grain sorghum crops.The research aims to scientifically substantiate and improve existing technological methods to increase the yield of grain sorghum plants, taking into account their morphobiological characteristics and reaction to the application of mineral fertilizers under various methods and depths of primary soil tillage. During the experiment, field, quantitative-weight, visual, laboratory, comparative-computational, and mathematical-statistical methods were used, employing widely recognized techniques and methodological recommendations.Results. The highest amounts of nitrates, mobile phosphorus compounds, and exchangeable potassium in the soil layer of 0-40 cm under grain sorghum crops during the years of the study were recorded against the background of the N60 nitrogen fertilizer dose applied during plowing to a depth of 28-30 cm. The lowest content of mobile phosphorus forms over the average of 3 years was observed in the disk tillage variant to a depth of 8-10 cm. The potassium content in the soil layer of 0-40 cm under grain sorghum crops over the average of 3 years of experimental research was characterized by a medium level. No significant difference was found in the utilization of available potassium by grain sorghum plants throughout the entire vegetation period, depending on the study factors. With an N30 dose, weed quantity increased by 1.4 and 2.2 times compared to the unfertilized background, depending on the soil tillage variant, and with an N60 dose, it increased by 1.3 and 2.1 times. The average yield of grain sorghum for plowing to a depth of 28-30 cm with the application of nitrogen fertilizers at a dose of N60 was 5.44 t/ha over the years of the study. For chisel tillage to the same depth, a yield of 3.89 t/ha was obtained, and for disk tillage, it was 2.54 t/ha.Conclusions. When growing grain sorghum in the conditions of the Southern Steppe of Ukraine, it is advisable to apply plowing to a depth of 28-30 cm against the background of nitrogen fertilizer application at a dose of N60, which creates favorable nutrient conditions and forms grain yield at the level of 5.44 t/ha.Keywords: grain sorghum, method and depth of tillage, nitrogen fertilizers, nutrient regime, weed infestation, yield.