Changes in agrochemical soil properties and spring wheat yields with reduced application rates of mineral fertilizers and application of Azofit N and Azofit P fertilizers

Abstract

The application of microbiological fertilizers Azofit N and Azofit P on soils with different fertility levels makes it possible to reduce the load on soil microflora when applying mineral fertilizers to spring wheat. When making comparative evaluation of the effect of microbiological fertilizers Azofit N and Azofit P with decreased fertilizer rates in the chernozem zone of the arid and moderately arid steppe of the Altai Region, certain changes in the agrochemical soil properties are observed. Through the use of microbiological fertilizers and reduction of mineral fertilizer application rates, the activity of soil microorganisms is enhanced and that contributes to the mobilization of nitrogen, phosphorus and potassium in the soil and the availability of nutrients for plants is improved. The highest grain yields of spring wheat were obtained in all areas of varying fertility when the rate of mineral fertilizers was reduced by 15% and Azofit N and Azofit P were applied. With decrease of mineral nutrition by 30% and 50% compared to the control, the application of microbiological fertilizers did not contribute to increase of grain yields of spring wheat. When comparing yields regarding fertility levels, the highest grain yields were obtained in the variants of high fertility level in the control and with decreased nutrition rates by 15% and 30%. The yields were more closely dependent on the content of mobile phosphorus and potassium by the end of the growing season. Significant dependence of the grain yield of spring wheat on the humus content in the soil was also revealed, because the content of organic matter in the soil significantly affected soil fertility and yield formation.