Soil agrochemical properties and spring wheat productivity depending on the fertilizers application methods

The aim of the study is to determine the influence of the methods of using micronutrient fertilizers (am-monium molybdate and copper chelate) on changes in the agrochemical properties of the soil and the productivity of spring wheat grain. The paper presents the results of field and laboratory research for 2017–2019 on the study of the influence of the methods of using ammonium molybdate and copper chelate (EDTA) on the change in the dynamics of mineral nitrogen and mobile phosphorus in chernozem-like soil under wheat agrophytocenoses of its productivity, conducted in the conditions of the southern agro-climatic zone of the Amur Region on the experimental field of the Far Eastern State Agrarian University, located in the village of Gribskoye Blagoveshchensk District. Field experiment scheme: 1) control without the use of fertilizers; 2) N30P30 (background); 3) background + seed treatment with ammonium molybdate; 4) background + seed treatment and spraying of vegetative plants with ammonium molybdate; 5) back-ground + treatment of seeds with ammonium molybdate + spraying of vegetative plants with copper chelate in the form of EDTA; 6) background + spraying vegetative plants with ammonium molybdate; 7) back-ground + spraying vegetative plants with copper chelate in the form of EDTA. The change in indicators of mineral nitrogen and mobile forms of phosphorus in the soil, as well as an increase in the yield of the main product - spring wheat grain, depending on the methods of using micronutrient fertilizers, was determined. It was found that the maximum value of mineral nitrogen in the soil was noted in the phase of milk ripeness in the variant with seed treatment before sowing and spraying vegetative plants in the tillering phase with ammonium molybdate – 72.1 mg/kg of soil, and mobile phosphorus in the tillering phase in the variant with treatment seeds before sowing with ammonium molybdate – 180 mg/kg of soil. The maximum productivity of the grain of the studied crop was noted in the variants with the treatment of seeds with ammonium molybdate and the double application of ammonium molybdate before sowing for seeds and during the growing season against the background of nitrogen-phosphorus fertilizers – 29.2 and 30.1 c/ha, respectively.