Monitoring of agrochemical and agrophysical properties of dark gray soil with different ways of its use

Summary The article presents the results of monitoring of the straw usage as an organic fertilizer on the complete mineral fertilizer, supplemented by additional nitrogen to narrow the C:N ratio in order to improve its decomposition into basic agrophysical and agrochemical indicators of dark-gray soil. It was found that during two rotations of crop the straw helped to reduce soil density, but there was a significant acidification of the soil. With a positive balance of organic matter in crop rotation, the use of straw fertilizer on the significant dominance of nitrogen in the composition of mineral fertilizers did not ensure the reproduction of humus reserves of the studied soils. During dump tillage, a significant decrease in the content of humic acid fraction was observed when using mineral fertilizers only. The usage of straw and additional nitrogen in the plowing led to a significant loss of total humus by reducing the proportion of fulvic acids. While the surface cultivation with this fertilizer, there is a tendency to increase the proportion of fulvic acids and reduce the amount of humus acids associated with calcium.