Abstract

Northern Kazakhstan is the main grain-producing region in the Republic of Kazakhstan. This paper presents a brief characteristic of soil climatic conditions and the results of long-term studies (n=600) on the diagnostics and optimization of the conditions of crops' nitrogen nutrition under insufficient and unstable moistening, which is typical for dryland Northern Kazakhstan. The methodological approach to the evaluation of the soil nitrogen state and the supply of nitrogen to crops were explicated. A new method of determining the need for nitrogen fertilizers and calculating their dose calculation was offered. The method was based on identification of the main factors of soil fertility that determine the efficiency of crops and the effectiveness of nitrogen fertilizers. On the basis of the correlation analysis, the quantitative correlation between the factors and the efficiency of crops was determined. The optimal parameters of nitrogen content in the soil, which provide for the maximum efficiency of crops, and ways of achieving such parameters were presented. The developed method allowed purposefully managing the soil nitrogen regime, with a view to optimizing nutrition and realizing the full potential of crops.