Agrochemical and biological soils properties in the mineral fertilizers and straw application

One of the ways to replenish humus reserves in agrophytocenoses is the use of straw of grain crops and soybeans as an organic fertilizer, since the plowing of their biological crop increases the supply of organic matter and increases the microbiological, biological and enzymatic activity of the soil. The paper presents data on the determination of agrochemical and enzymatic properties of zonal soil types in the Amur Region when straw and mineral fertilizers are used. Brown forest soils, brown forest gley soils, meadow chernozem-like soils, and alluvial soils, the most common in the Amur Region, were selected for research. To study the properties of the studied soils, a laboratory experiment was laid with various options for applying grain and soy straw and mineral fertilizers. Ammonium nitrate (N30) and potassium phosphate monosubstituted (P30) were chosen as mineral fertilizers. The laboratory experience was divided into 2 composting periods - 90 and 180 days, to assess the degree of straw degradation, depending not only on the applied fertilizers, but also on hydrothermal conditions. The study found that the selected soil types are characterized by a slightly acid reaction of the soil environment, very low and low humus content, medium and high content of mobile phosphorus, high and high content of mobile potassium. It has been established that the period of straw composting does not affect the reaction of the soil environment. On all types of soils, there is a tendency to increase the content of organic matter, ammonium nitrogen, mobile phosphorus and potassium in the second composting period with the use of mineral fertilizers and straw. The studied soil types are characterized by very weak and weak activity of the urease enzyme, medium and very high activity of phosphatase. When studying the activity of enzymes, it was found that when using all fertilizer systems, the activity of urease is higher in the first period of composting, the activity of phosphatase - in the second period of composting. The activity of enzymes in different types of soil varied when mineral fertilizers and straw were applied.