Off-line differential fertilization is one of the science-intensive technological processes in the precision farming system. The process ensures the change of the norm during the movement of the device in the field in the automatic mode according to the task map compiled on the personal computer for the elementary parts of the field. In the conditions of Western Siberia, studies have been conducted to identify the effectiveness of a differentiated method of applying nitrogen fertilizers for the planned yield of spring wheat of 3.0 t/ha. Off-line implementation of the technological process allows reducing the rate of fertilizers by 7.7-21.1%, production costs by 1.9-3.4% compared to the traditional method. It is shown that the application of top-dressing in off-line mode increases production costs by 10.2%, the rate of ammonium nitrate - 34.4-68.5% relative to the differential application of 4.0 t/ha to the planned yield of spring wheat.

Using an unmanned aerial vehicle Geoscan 201 Agro, 20,286 hectares of agricultural land were surveyed in Tyumen and Sverdlovsk regions, where 206 fields were with an area of 5,552 hectares. Creating electronic maps when piloting an UAV is a more accurate, operational method in comparison with the use of the circular tour method and the use of a space satellite. It allows getting the geographical coordinates of the boundaries of the field, calculating its area, forming orthophotomaps and an electronic image of the fields.

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The paper describes the theory and the experimental results for the synthesis of precision waveforms by using the pulse-width modulation of the power of the microwave, which drives the superconductor–insulator–normal metal–insulator–superconductor Josephson array. The synthesized sine waveform has a high precision. Its harmonic content was determined to be less than 0.003%. This degree of harmonic content is in agreement with the theory.

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The paper discusses the dynamics of different types of overdamped Josephson junctions biased by a sinusoidal microwave current. The results clarify the theoretical background for optimizing the single junction and the junction array parameters for their use as alternating current (ac) wave form synthesizers. The determined phase lock areas demonstrate the degree of overlap for Shapiro steps [S. Shapiro, Phys. Rev. Lett. 11, 80 (1963)] of different orders as a function of the normalized frequency μ=2πfωc−1, where f is the microwave frequency and ωc is the Josephson junction characteristic frequency. For μ⩽0.7, which is a typical operation range for superconductor-insulator-superconductor Josephson junctions in the conventional direct current (dc) voltage standard at the bias frequency range from 10to100GHz, the Shapiro steps overlap completely. For μ⩾1.4 [typical for superconductor-normal-superconductor junctions at the same frequency range], the steps do not overlap. This allows for ac voltage synthesis by means of binary arrays and pulse-driven systems. For 0.7⩽μ⩽1.4 there is a range of partially overlapping Shapiro steps, which allows a rapid switching of the Josephson dc voltages for ac synthesis by microwave power modulation. Experimentally we have achieved this range through properly designed superconductor-insulator-normal-insulator-superconductor junctions.

Spring wheat is widely used as a raw material for the production of human food and animal feed. This study was aimed at investigating the response of spring wheat to different levels of mineral nutrition. The article presents the results of applying mineral fertilisers when growing spring wheat of the Novosibirsk 31 variety in the Tyumen region. The following parameters were determined: wheat grain yield, grain nutritional quality (protein content, raw gluten, gluten quality, grain hardness, grain-unit value), and amino acid and elemental (N, P, K, S, Na, Mg, Ca, Cl) composition. The efficiency of mineral fertilisers was shown to depend on their dosage, as well as on soil and weather conditions. In 2018, the use of mineral fertilisers led to an increased wheat yield and an improved grain quality. Thus, in comparison with the control (no fertilisers), the wheat yield increased by 1.6 t/ha, while the protein and wet gluten content grew by 3.67% and 9.9%, respectively. The application of fertilisers allowed 3rd class wheat to be obtained, while experiments involving no fertilisers produced only 4th class wheat. It was revealed that the role of mineral fertilisers in wheat yields and their quality decreases when growing wheat on leached chernozem under favourable weather conditions. Thus, in 2019, 3rd class wheat varying in yield insignificantly was obtained in all experiments (with and without fertilisers). It was confirmed that an increase in the dose of mineral fertilisers leads to an increase in the content of glutamic and aspartic acids in the grain, at the same time as decreasing the content of arginine. The elemental composition of grain, except for nitrogen, does not depend on the dose of fertilisers.