The Effect of Differentiated Nitrogen Fertilization using Satellite Navigation Systems on the Spring Wheat (Triticum aestivum L.) Crop Yield in the Conditions of Chernozem-Like Soils in the Northern Forest Steppe of the Tyumen Region of Russia

Soil cultivation without layers turnover impeded the process of nitrate nitrogen accumulation compared with plowing. The traditional scheme of mineral fertilization applying the averaged standard did not create a heterogeneous level of nutrient supply in primary soil cultivation systems. These factors set them in unequal conditions by default in terms of nitrogen supply to crops. Solid mineral fertilization with the use of precision farming systems in subcompartments, taking into consideration nutrient concentration in soil and the estimated crop yield changes the function of nitrogen status formation. The aim was to study nitrogen status while applying an innovative approach to primary soil cultivation using satellite navigation systems. The experiments were carried out on meadow-chernozem, and nitrogen status was studied in plowing, differentiated, subsurface tillage, and soil cultivation without layers turnover. Nitrate nitrogen was defined by the ionometric method. Moderate supply was registered in plowing and differentiated tillage in the 0-20 cm layer with 10.1-11.8 mg/kg. During the tillering phase, N-NО₃ supply amounted to 16.6-15.2 mg/kg which indicated a high supply of crop plants. On fields with subsurface tillage and no primary soil cultivation, a moderate supply of nitrate nitrogen was observed-10.1-10.8 mg/kg. Innovative technology including differentiated mineral fertilization decreased spatial variability of N-NO₃ supply to 8.2-10.4 mg/kg before spring wheat (Triticum aestivum L.) seeding, during tillering phase its variability dropped to 15.3%, having the benefit of accumulation with resource-saving tillage: 11.9-12.7 mg/kg. Optimization of nitrogenous nutrition in the case of differentiated mineral fertilization with precision farming systems application in off-line mode helped achieve the maximum spring wheat yield-3.63-4.03 t/ha in soil cultivation without turning over layers.