The effect of macro- and microfertilizers on agrochemical soil characteristics and spring wheat yield under conditions of the Right bank of the Volga-River in Saratov region

The paper specifies how the application of micro- and macrofertilizes changes typical black soil nutrient regime and physicochemical properties in spring wheat plantings. It was determined that the most acceptable nutrient regime was formed with combined usage of ammophos and such chemicals as Micromac and Microel. During these experiments nitrogen concentration amounted to 8.50 and 8.25 mg kg -1of the soil, and available phosphorus was 60.0 and 57 mg kg-1, respectively. The control gave the maximum amount of exchangeable potassium (242.5 mg kg-1), whereas the lowest rate was registered with combined usage of Micromac and Microel against the background of ammophos (231.6 mg kg-1). At the end of growth the nutrient regime significantly degraded due to the increasing plant nutrition of spring wheat. The influence of fertilizers on soil cation content was analyzed. Total absorbed bases insignificantly increased in applying fertilizers compared to the control, particularly with combined usage of micro and macrofertilizers, when this amount reached 44.45 mg-equiv per 100 g of soil. The highest yield has been observed with combined application of micro- and macrofertilizers, reaching 1.86 t ha-1, while the lowest yield has been shown in the control (1.22 t ha-1). The amount of calcium and magnesium cautions increased within SAC