EFFECT OF MINERAL FERTILIZERING DEPENDS ON AGROCHEMICAL AND TECHNOLOGICAL CONDITIONS OF THEIR USE

The effects of mineral fertilizers have been shown to depend on different conditions of their use – agrochemical and technological. When choosing the type of fertilizer, it is necessary to base it on the properties of the soil, the predecessor and the previous fertilizer application system in each individual field. Based on the results of long-term stationary experiments at the Kurgan Research Institute of Agriculture, approximate doses of nitrogen and phosphorus have been established depending on the content of N-NO₃ and mobile P₂O₅ in the soil. The content of exchangeable potassium in most of the chernozems of the Kurgan region is sufficient. The choice of fertilizer form, dose, method, and time of application changes their effectiveness both agrotechnically and economically. In one experiment, when comparing the effects of ammonium nitrate, urea, and ammonium sulfate on the yield and quality of spring wheat, urea lost slightly, while ammonium sulfate had a slight advantage. In another experiment, ammonium nitrate and urea were equivalent in the pre-sowing period for wheat, and early fertilization showed a slight loss of urea, but it benefited from a combination of early and late fertilization. The most profitable of the methods of applying simple and complex fertilizers turned out to be local, both before sowing and during sowing. Liquid fertilizers tested in corn sowing were slightly more effective than solid fertilizers. It is convenient to evaluate the effect of different doses of nutrients in crops in experiments with a sufficient set of doses. It is necessary to take into account not only the overall increase in yield, but also the marginal increase from each step of increasing the dose. In an experiment at the Makushinsky experimental field testing doses of phosphorus P15–30–45 on soil where superphosphate was highly effective, the marginal yield increases were compared. The marginal increase in grain yield and the marginal payback from the first P15 were the highest. The two subsequent P15s, as they were added to the first portion, were characterized by a decrease in yield growth and a 2.3–2.6 times decrease in the active ingredient of fertilizers.