Application of mineral fertilizers in resource-saving cultivation technologies of spring wheat on ordinary chernozem

The present research was carried out to improve the use of mineral fertilizers and to study their impact on the yield of spring wheat in the field cereal-fallow crop rotation using traditional and resource-saving farming systems under the conditions of North Kazakhstan. Field experiments were carried out in 2015-2017 on the ordinary chernozem in the Kostanay Region. The availability of nitrate nitrogen (N-NO3 - 11.2 mg/kg) and mobile phosphorus was average (Р2О5 content in the 0-20 cm layer amounted to 80 mg/kg, according to Chirikov), mobile potassium was high (К2О - 420 mg/kg, according to Chirikov), humus content - 5.4%, pH (aqueous) - 6.6-7.0. It has been found that the highest degree of availability of nitrate nitrogen in plants at the beginning of vegetation is observed in wheat crops after fallow using traditional cultivation technology. The lowest content of nitrate nitrogen in the soil was observed in wheat crops cultivated permanently under zero cultivation technology at the beginning of summer in these years. A systemic effect of cultivation technologies on the phosphorus content of soil has not been noted. A difference in the content of mobile phosphorus in the soil can be noticed between the control and the application of N30P20. By the flowering phase, there is a significant decrease in nitrate nitrogen reserves in the soil. Both options of cultivation technology show a positive correlation between the content of nitrogen in the soil and the dose of suction application of nitrogen fertilizers (N30 and N30P20). The content of mobile phosphorus in the soil varies less than the content of nitrate nitrogen during this period and remains at the level of average plant availability. The maximum yield of spring wheat was obtained after fallow and amounted to 1.78-2.28 t/ha. As the 2nd culture after fallow, wheat yield ranges from 1.75 to 2.04; as the 3rd culture from 1.44 to 2.03 t/ha. The lowest wheat yield was obtained in permanent crops and amounted to 1.30-1.86 t/ha. On all wheat fields included in the experiment, the maximum grain yield in both options of cultivation technologies was obtained with the joint application of nitrogen and phosphorus fertilizers, the increases from the application of nitrogen fertilizers in pure form were less significant. The efficiency of using mineral fertilizers in traditional wheat cultivation technologies becomes higher with time passing from fallow. With zero tillage, the response of wheat to fertilizer application changes and the use of fertilizers after fallow becomes no less effective than with other, non-fallow, forecrops. The amount of gluten in the grain on the N30 and N30P20 backgrounds increases by 1.5-2.0% if compared to non-treated backgrounds. With times passing from fallow, there is a gradual decrease in the crude gluten content of the grain.