Prospects for nitrogen fertilization management of corn crops: a review of modern concepts

Abstract

The main purpose of this review was the problem of optimizing nitrogen fertilization of corn crops in the light of recent trends, taking into account the requirements of the ecological and economic approach to the development of cultivation technologies. Based on the review of the research results by Ukrainian and foreign scientists, modern methods of nitrogen fertilization management are described. In particular, this concerns the differentiated application of nitrogen fertilizers using complex organic-mineral fertilizers, which comprise humic compounds, nitrification inhibitors and urease inhibitors. The review draws attention to controversial issues of corn crops’ fertilization and contradictions regarding the effectiveness of the use. These include the rate of nitrification of the soil rhizosphere, inhibition of nitrification processes and the effectiveness of the impact on yield formation. The information on the efficacy of using 3, 4-dimethylpyrazole phosphate and thiophosphoric triamide as nitrification inhibitors from economic and environmental points of view is given in the article. A brief analysis of the use of the group of 2-(3, 4-dimethyl-1H-pyrazol-1-yl) isomeric mixture of succinic acid, nitrapyrin or pronitridine is conducted. Attention is paid to the peculiarities of the behavior of nitrification inhibitor substances depending on the properties of soils and climatic factors. The conclusion is made as to the simultaneous use of two strategies – the application of urease inhibitor and nitrification inhibitor. The presented review of scientific sources does not indicate the unanimity of opinions concerning the use of nitrogen inhibitors. Scientists are overwhelmingly inclined to the usefulness of applying inhibitors to reduce greenhouse gas emissions into the atmosphere and the economic efficiency of reducing the rates of nitrogen fertilizers’ application, but there are also data on the questionable impact of inhibitors on nitrogen losses into the atmosphere and their impact on yield formation. On the one hand, nitrogen inhibitors can be crucial in reducing nutrient losses and increasing the effectiveness of the use of expensive nitrogen fertilizers and raising plant productivity by 41–79 %, especially when applying stabilized nitrogen fertilizers of increased efficacy. They play an important role in the 4R cultivation concept, which envisages ecological and economic approach to growing crops. On the other hand, while reducing nitrogen losses, they do not increase yields in any way, especially in combination with the use of such fertilizers.