Algorithm for assessing the nutrition elements (N, P, K) participation in the increased potato yield formation under the northern Kazakhstan steppe conditions

The purpose of research is to reveal the effectiveness of mineral fertilizers for potatoes in various doses and combinations in the conditions of Northern Kazakhstan. The analysis of experimental data made it possible to reveal the regularities of the influence of various doses and combinations of mineral fertilizers on the yield of potatoes in the conditions of Northern Kazakhstan. The use of nitrogen fertilizers made it possible to obtain a yield in two years of research from 34.4 to 35.5 t/ha. Doses of N45-135 made it possible to obtain an increase of up to 4.2 t/ha, or 13.4 % in relation to the control; the increase was 6.2-9.7 % compared to the background value. The application of N90 increased the yield to 35.3 t/ha, and with a further increase (up to N135 kg/ha), the effect of nitrogen was less significant. When making phosphorus 45 kg a.i. against the background of N45K45, the yield of potato tubers increased (an increase of 3.1 t/ha), but when 90 kg of a.i. the increase was 6.5 t/ha. Against the background of nitrogen and phosphorus, the introduction of potash fertilizers (K45-90) on average over the years of research slightly increased the yield (an increase of 1.3-1.5 t/ha). The relationship between nitrogen doses and potato yield was high (r = 0.95), phosphorus - strong (r = 0.98), potassium - medium (r = 0.74). Mathematical dependencies were expressed by the following regression equations: УN = 0.0322x + 32.58, УP = 0.0722x + 31.25, УK = 0.0167x + 33.283. On average, each kilogram of nitrogen, phosphorus and potassium increased the potato yield by 32.2, respectively; 72.2 and 17 kg. The indicators obtained by the correlation-regression method ("bN", "bP", "bK") characterize the dynamics of the relationship between two variables "x" - fertilizer doses and "У" - potato yield.