Міграція нітратного азоту за внесення азотних добрив у виробничих посівах кукурудзи

Abstract

Goal. To determine the dynamics of the migration of nitrate nitrogen in the soil during the active growing season of corn with the application of nitrogen fertilizers in production conditions. Methods. Field — to determine the dynamics of nitrate nitrogen migration, laboratory-analytical — to determine the content of mineral nitrogen in the soil, mathematical-statistical — to assess the reliability of the obtained data. Results. It is proven that the fractional application of nitrogen fertilizers provides prolonged saturation of the soil with mineral nitrogen at elevated, high, or very high levels during the active growing season of corn. The maximum content of mineral nitrogen was fixed in the upper layer of the soil 0–20 cm. It was established that in typical chornozem, when N136 is applied in the soil layer 0–20 cm, the nitrate nitrogen content decreased over time — from May to September by 5.9 times, with depth — by 2.8–4.8 times in the layer of 100–120 cm compared to its content in the upper layer of 0–20 cm. With the application of N119 and N134, its growth in the soil layer of 0–20 cm was established in the interval between pre-sowing application and top dressing, where the content of nitrate nitrogen decreased at a depth of 100–120 cm compared to the content in the upper layer of 0–20 cm by 1.2–6.1 times. The highest yield of corn grain was obtained with fractional application of N136 and N134 (r = 0.77–0.84). Conclusions. It was established that with the fractional application of N119–N136, the content of nitrate nitrogen in the soil decreased with depth and over time, ensuring the formation of corn grain yield in production conditions of more than 10 t/ha. In dryland areas with deep underground water, it is unlikely that they will be contaminated with nitrate nitrogen at a fractional application of N119–N136/ha, where its maximum content is fixed in the soil layer of 0–20 cm.