Nitrogen-containing compounds seasonal dynamics and agrichernozem enzymes activity using zero treatment technology

The purpose of research is to evaluate the content and dynamics of organic and mineral forms of nitrogen, as well as enzymes of the nitrogen cycle under conditions of zero tillage technology. The studies were carried out in a production experiment, laid down in the Shilinskoye SPK in the Krasnoyarsk forest-steppe, within the Chulym-Yenisei denudation plateau on the southwestern outskirts of Central Siberia (56°37' N and 93°12' E). The period of validity of the studied technologies by the beginning of observations was seven years. In the industrial sowing of field crops, a reference plot of an elongated shape with an area of 500 m2 was allocated. Soil samples were taken from layers 0-5 and 5-20 cm using the snake method. The sample size (n = 15) was calculated based on the soil fertility variation determined before the experiment. The soil cover is represented by a combination of leached medium- and high-humus medium-thick clayey silty chernozems. The cessation of mechanical mixing of the soil with the preservation of plant residues on the soil surface inhibits the mineralization of labile organic compounds during the formation of the production process of plants. The seasonal rhythm of the dynamics of nitrogen in compounds that are difficult to and easily hydrolyzed also indicates a suppression of the activity of processes that trigger the decomposition of compounds of a protein nature. Significant changes in the content of mineral forms of nitrogen are associated with the redistribution of plant phytomass in favor of the aerial part of the arable layer. The accumulation of oxidized nitrogen compounds increases in the second half of the growing season. Enzymatic activity reflects the stages of conversion of nitrogen-containing compounds. Soil urease activity is more sensitive to changes in the main tillage method compared to proteolysis activity.