As a green manure there were studied such crops as pea (cv. ????? (Gotik), spring rape (cv. ??????? (Tavrion), Brassica juncea (cv. ??????? 8 (Donskaya 8), buckwheat (cv. ??????? (Kazanka), and lupine (cv. ????????? ??????? (Orlovskiy siderat). The crops were cultivated according to zonal agricultural technologies at ordinary chernozems. Soil moisture was maintained at 70 % of field capacity (FC). Observing the duration of vegetative phases of the green manure crops has shown that the most long vegetative period had spring rape (47 days). The vegetative periods of other crops were less by 7-9 days; buckwheat and pea had the shortest one – 38 days. The relationship between the vegetative period duration and water availability was recorded. So, until the beginning of flowering the vegetative period extended by 1-2 days in wet year. The highest indices for linear growth, the yield of green mass in the flowering phase and the accumulation of root-stubble residues was recorded at the plots of Brassica juncea, in average they were 113.9 cm, 36.1 t/ha, and 11.5 t/ha respectively. Brassica juncea and pea were the most responsive on moisture conditions of a year; the height increasing was 12.8 and 7.7 cm respectively. The soil received 34.3 and 28.0 t/ha of organic mass by incorporating rape and buckwheat. Legumes had the least indices: pea – 24.7 t/ha and lupine – 18.6 t/ha. After green manure crops incorporating at the studied plots, the dynamics of nutrients in the soil layer 0-20 cm have shown the increasing of nitrates by 10.2-15.5 mg/kg, mobile phosphorus – by 9.4-13.6 mg/kg, exchangeable potassium – by 42-56 mg/kg. The increasing of nutrient (NPK) content in soil was recorded at all variants of experiment and in all soil layers up to the depth of 100 cm.
