THE USE OF NITROGEN FERTILIZERS UNDER SPRING TRITICALE AND WHEAT ON DARK-CHESTNUT SOIL OF DRY STEPPE ZONE OF KAZAKHSTAN
Experience with the use of a stable isotope of nitrogen <sup>15</sup>N evaluated the impact of fertilizers on grain yield of spring wheat and spring triticale on the dark chestnut soil in the dry zone of Northern Kazakhstan. The maximum yield of grain of spring wheat obtained by pre-sowing dose N<sub>60</sub>, spring triticale it received 2.2 times higher when making N<sub>60</sub> equal parts before planting and at tillering. The effect of nitrogen fertilizer on yield of both crops, more efficient on the background of phosphate fertilizers. Both crops on the formation of the yield is used 30% of the introduced doses of nitrogen fertilizer, is fixed in the soil under spring wheat with 32%, under spring triticale — 34%, gaseous losses of nitrogen fertilizer are the first culture — 38%, the second 36%. The maximum use of nitrogen fertilizer on yield formation of 41–42% is typical for both crops when making planting to N<sub>30</sub> in both phosphoric backgrounds. As a result of better use of nitrogen by plants fall to 15–26% of the gaseous losses. The use of spring crops to nitrogen fertilizer depends on the dose deposited nitrogen fertilizer, when it is increasing twice as on the background P<sub>0</sub> and on the background of P<sub>60</sub> utilization of nitrogen fertilizer is reduced almost two times from 41-42 to 23-28%. Fractional introduction N<sub>60</sub> equal parts before planting and at tillering practically does not change the size of the use of nitrogen fertilizer on yield formation of both crops. Introduction tillering N<sub>30</sub> reduces the utilization by plants of fertilizer compared to the same caused by pre-sowing his dose