The article is devoted to the study of the influence of various crops used as green manure on the biological properties of the soil. In the conditions of the forest-steppe of the Sverdlovsk region. The results of the microbiological activity of the soil, which were carried out using the method of linen cloths, are presented. The cloth was laid in layers the following year after the incorporation of green manure during the period of the highest activity of microorganisms. In the first year of the green manure's aftereffect in 2019, the microbial activity ranged from 61.4% (buckwheat) to 78.0% (mustard). In the second year, the decrease in linen fabric ranged from 23% to 51%, which was on average two times lower than in 2019. This can be attributed to the presence of moisture in the soil. The number of earthworms varied from 227 (peas) to 347,000 (lupine) in 2019, and from 160,000 (rapeseed) to 253,000 (mustard and peas) in 2020. The mass of worms per hectare is an interesting indicator that indirectly assesses the amount of soil processed by earthworms. It is known that under favorable conditions of moisture and heat, one earthworm can process the weight of soil equal to its own weight in one day. The data on the mass of earthworms correlates with the data on their number. The highest mass of earthworms was observed in 2019 and 2020 in mustard, with 212 and 164 kg/ha, respectively. The highest yield of green mass was obtained from phacelia and a mixture of peas and oats, at 34.7 and 32.7 t/ha, respectively. It was found that the yield of barley and wheat was strongly and significantly influenced by the green mass of green manure crops.