Green manure is an important source of replenishment the missing amount of organic and mineral fertilizers for modern agricultural enterprises. Therefore, the aim of the study was to identify the role of green manure crops in increasing soil fertility and crop productivity. The plowing of the green mass of the under-cover clover for green manure provided the optimum values of volumetric mass, porosity and air capacity, as well as higher moisture content in the soil layer of 0-30 cm. The intensity of cellulose decomposition in winter wheat crops 4 months after plowing of clover in the soil layer of 0-10 cm was 52.3%, of 10-20 cm was 50.9%. Subsequently, the yield of winter wheat according to the variant with clover green manure was higher than without green manure. The intensity of the negative impact of burning straw on soil fertility indicators depends on its mass, stubble moisture, and topsoil. Plowing straw and applying nitrogen fertilizers under the stubbly green manure crop - spring rape - contributed to an increase in organic matter, which positively affected the quality and yield of potato tubers. On average, for 3 years, the combined use of straw, nitrogen fertilizers and green manure contributed to obtaining the largest potato crop, while the increase in comparison with control was 34.0%.

The article considers the symbiotic activity of chickpeas and soybean crops depending on the action of various herbicides and fertilizers. In the field conditions of the forest-steppe zone of North Ossetia-Alania, the effect of mineral fertilizers on the symbiotic activity of promising varieties of chickpeas was studied and it was established that mineral fertilizers had a significant effect on the formation of the symbiotic chickpeas apparatus. Mineral fertilizers contributed to the increase in the average mass of nodules and their number. According to the mass of active nodules formed by Vilana soybean plants, increasing the dose of complex fertilizer Nagro to 0.5 l/ha is justified, since the mass of nodules on one plant in this variant increased in development phases. All options with the introduction of bio fertilizer Nagro for soybean crops were characterized by a significant increase in the mass of nodules in comparison with the control variant. Control variants formed more inactive nodules on the lateral roots, which were also characterized by smaller sizes.

The article presents the results of studies on the seeding time of perennial forage crops in the foothill area of North Ossetia-Alania. An agricultural method which is necessary is the pre-sowing treatment of seeds with natural agronomic ores in a ratio of 1:2 and simultaneous seed scarification. The studies revealed that the most optimal seeding time in terms of field germination and plant safety for harvesting for all the studied crops was the variant of the middle seeding time in the second ten-day period of May, when the soil temperature was warmed up to 12-14 °C. Also, when seeded late, the plantings of the studied crops significantly decreased in terms of leaf area—by 1.9 thousand m2/ha for burnet, by 1.2 thousand m2/ha for clover, by 1.5 thousand m2/ha for medicago, by 1.5 thousand m2/ha for sainfoin, by 1.5 thousand m2/ha for galega, by 0.8 thousand m2/ha for festulolium. Over four years, the average biochemical composition of perennial grasses of different seeding periods did not differ significantly in the content of forage units, digestible protein and metabolic energy. Thus, depending on the seeding time, fluctuations in the content of forage units were as follows: 2.21-2.24 t/ha for clover; 2.09-2.21 t/ha for medicago; 2.34-2.46 t/ha for sainfoin; 2.69-2.79 t/ha for galega; 2.27-2.41 t/ha for festulolium; 2.56-2.74 t/ha for burnet. The digestible protein content, respectively: 0.37-0.44 t/ha for clover; 0.51-0.55 t/ha for medicago; 0.49-0.54 t/ha for sainfoin; 0.43-0.57 t/ha for galega; 0.38-0.44 t/ha for festulolium; 0.57-0.64 t/ha for burnet. The output of metabolic energy was: 48.9-51.7 GJ t/ha for clover; 38.4-43.2 GJ t/ha for medicago; 39.3-42.4 GJ t/ha for sainfoin; 41.7-46.3 GJ t/ha for galega; 48.7-52.3 GJ t/ha for festulolium; 40.5-42.7 t/ha for burnet. Moreover, the crops of early and medium time of seeding had the highest values of biochemical composition.

В статье приводятся результаты исследований по изучению гербицидов нового поколения и минеральных удобрений на посевах кукурузы в предгорной зоне РСО-Алания. Ключевые слова: кукуруза, минеральные удобрения, гербициды, урожайность.