The effect of nitrogen fertilizers on the productivity of grain sorghum

Due to the warming and increasing aridity of the climate in the steppe regions, the selection and introduction into production of high-yielding, drought-resistant crops, one of which is grain sorghum, becomes relevant. The use of mineral fertilizers is of a great importance in increasing its productivity. The purpose of the research is to determine the most effective dose of nitrogen fertilizer for grain sorghum with pre-sowing application of phosphorus fertilizers on the optimal background. It has been established that the most appropriate doses of pre-sowing nitrogen fertilizer range from N-45 to N-60 kg / ha of active ingredient. At this dose, an average of 4 years of research yielded the highest yield of sorghum grain (5.81 t / ha). In comparison with control, the increase was maximum and amounted to 0.91 t / ha. The introduction of N-30 and N-90 kg / ha allowed to obtain an additional 0.69 and 0.89 t / ha of grain. The use of the recommended dose of nitrogen contributed to the high collection of feed units (7.06 t / ha) and crude protein (6.10 t / ha). The energy content in the sorghum grain harvest during the years of research was the most significant (73715 MJ / ha) was also established with the addition of N-60 kg / ha. Averaging the morphological and structural indicators of the grain sorghum crop depending on the doses of nitrogen fertilizers used indicate that the height of the plants increased and its maximum (94.8-95.5 cm) was established when N-60-N-120 kg / ha was applied. The panicle length (22.6 cm), the weight of 1 panicle (34.2 g), the grain mass in a panicle (29.1 g) were the highest when using N-45-N-60 kg / ha of active substance..