Long field experiments were carried out using two methods for assessing biological activity in the arable layer of sod-podzolic soil. The biological activity of the soil was established by the intensity of decomposition of the linen and using tea bags at the junction of the methodology of the University of Utrecht (Netherlands) and Umea (Sweden). It was noted that the biological activity of the soil with a rating of "strong" was on all options, but only when using mineral components as fertilizer. In 2017, in the option using only phosphorus fertilizer, the biological activity was rated "very strong". In variants using the organomineral system, the biological activity of the soil was rated "strong" and "very strong". When determining the biological activity of the soil by the method of decomposition of organic matter of tea, similar results were obtained. As a consequence, against the background of organic and organomineral systems, it was proved that the biological activity of sod-podzolic soil in the conditions of the western part of the Non-chernozem zone is maximum.
