Abstract
The article shows that in the agro-industrial complex of Northern Kazakhstan, much attention is paid to the issues of progressive improvement of soil fertility, crop yields, increasing the production of grain, feed and other crops based on a scientifically based farming system. Currently, the acreage should be carried out in the crop rotation system and a special place is occupied by the problem of providing the population with high-protein and balanced fatty foods. The introduction of oilseed flax into diversified types of field crop rotations contributes not only to providing the national economy with oilseed products, but also to improving the agrophysical, biological and agrochemical properties of ordinary chernozems. In addition, flaxseed contains a large amount of balanced and easily digestible protein, vegetable oil, various sugars and carbon waters, as well as essential vitamins and trace elements needed in the diet. Field experimental studies were conducted to identify the effect of the effectiveness of mineral and organic fertilizers on improving soil fertility, the formation of the size and quality of flax crops, and to determine the most effective option in the northern region of Kazakhstan. The optimal use of mineral and organic fertilizers caused a positive effect of flax plant cenosis on the density, in particular, on the field germination of plants, plant growth dynamics, accumulation of raw and dry mass of flax plants. The optimal use of mineral and organic fertilizers contributed in addition to increasing soil fertility on plant yields and profitability of growing oilseed flax.