Optimization of a mineral nutrition of a milk vetch east (Galega orientalis) on the basis of soil diagnostic gray forest soils

The aim of this study is to diagnose the needs of a milk vetch east in mineral fertilizers based on soil chemical analysis and set optimal values and ratios of nutrients. Experiments were laid on gray forest soils in the sub-taiga zone of the Omsk region. Soil and climatic conditions of Western Siberia subtaiga zones allow to obtain the yield of green mass to 142.1 t/ha, while providing yield increase to 45.4 tonnes per hectare, or 46.8 percent. It was found that the gray forest soils of average availability of plant nutrients, introduction of nitrogen under a milk vetch east contributed to the increase of nitrate nitrogen in the 1.4 mg/kg (15.6%), mobile phosphorus 12.5 mg/kg (16.6%), a potassium exchange at 5.0 mg/kg (7.9%) in the 0-20 cm layer of soil. On the basis of mathematical relations in the system “soil - fertilizer” proposed formula for calculating doses of potassium and phosphate fertilizer for fodder vetch east. Coefficients calculated intensive actions phosphorus incoming units (b1 = 0,067) and potassium (b2 = 0,030) in the soil (kg/ha). As a result of statistical analysis of studies found that the introduction of phosphate fertilizers in the soil increases phosphorus content about twice and slightly increases the nitrogen content and potassium. For 142.1 t/ha of green mass of vetch east optimal levels of the nutrient status of the soil are: nitrate nitrogen - 12 mg /kg, mobile phosphorus - 150 mg/kg and exchangeable potassium 116 mg/kg.