The effect of the nitrification inhibitor 3,4-dimethylpyrazole phosphate on the productivity of winter rape under different rates of nitrogen fertilizers

Abstract

Goal. To study the influence of the use of the nitrification inhibitor (NI) 3,4-dimethylpyrazole phosphate at different rates of nitrogen fertilizers and the application of urea-ammonia mixture (KAS-32) on the yield of winter rape seeds. To determine the difference in the yield of winter rape under the conditions of using different norms of KAS-32 with and without the addition of NI. Methods. Field (stationary experiment); laboratory (agrochemical analysis of soil and plant samples); analytical (systemic analysis of long-term results of field experiments and meteorological observations); mathematical-and-statistical; correlation and regression analysis; mathematical modeling, and empirical generalization of established regularities. Results. It was confirmed that the use of nitrification inhibitor with KAS-32 significantly influenced the yield of winter rapeseed. On average, over the 3 years of research (2018, 2020, and 2021) conducted at the «Druzhba Nova» scientific research center located in Varvinsky district of Chernihiv oblast (branch of the Cornell Agricultural Holding) for the same rate of nitrogen fertilizers in the variant «the background + N130» with the use of NI, the yield increased by 0.37 t/ha, or 13.3% compared to the variant «the background + N130» without the use of NI. In the variant with a reduced rate of nitrogen fertilizers «the background + N120» with the use of NI compared to the option with an increased rate of nitrogen fertilizers «the background + N130», but without the use of NI, an increase in yield by 0.27 t/ha, or 9.7%, was also recorded. Conclusions. It was established that the yield in the variants «the background + N120» and «the background + N130» using a nitrification inhibitor compared to the control N10P30K40 (background) increased by 0.58–0.68 t/ha (23.4–27.4%), in the variants «the background + N120» and «the background + N130» with the use of NI compared to the variant «the background + N130», but without the use of NI, the yield increased by 0.27–0.37 t/ha (9.7–13.3%) over 3 years of research (2018, 2020 and 2021).