In arid zones, the yields of soft winter wheat varieties are particularly affected by the variations of hydrothermal conditions. This especially applies to direct seeding practices, for which the understanding of the links between hydrothermal parameters of soil and the environment, on one side, and the productivity of winter wheat, on the other, is one of the founding pillars of stable agricultural systems. On the case of the arid zone of Central Fore-Caucasus, this study investigates changes in the duration of interphase periods of plant development, plant density, and yield. It is found that in 2019–2021, positive temperature shifts and drought resulted in an increase in the duration of the growing season of crop varieties, thinned plant density, and reduced productivity of drought-resistant varieties. Evaluation of indices, that determine the ecological and genetic variability of varieties in the “genotype-environment” system resulted in the establishment of models that described the effect of drought on crop yields by type of manifestation and forecrops (sunflower, chickpeas). It is shown that the average linear deviations improved phase techniques and changed the area of winter wheat cultivation. On the back of the further drought propagation, farmers in arid zones could benefit from breeding new varieties and hybrids of grain crop. These measures may increase or stabilize the productivity of winter wheat in arid environments. Specifically, for the arid zone of Central Fore-Caucasus, the study recommends reducing lands under grain crop and shifting the cultivation of winter wheat northward. This will reduce the impact of volatile climatic conditions on winter wheat productivity in the region.

The problems of improving the tillage systems and crop cultivation technologies are of particular relevance both in terms of energy savings and, in general, resource conservation. The article describes various tillage systems using machines and implements of domestic and foreign production for the arid zone of southern Russia. The initial position in the development of cultivation technology of crops are agroecological requirements of the crop and variety to the growing conditions. Sequential overcoming of factors that reduce crop yields and product quality allows us to form the most optimal growing technology for specific climatic conditions of the economy. The article describes the tillage systems - moldboard, resource-saving using domestic tillage equipment, resource-based on foreign technology and recommended using combined technology, which has different effects on the conservation and accumulation of productive moisture. With the moldboard tillage, these indicators are the smallest, and resource-saving systems give approximately the same results when determining the stock of productive moisture in all phases of crop development. Different tillage systems for crop rotation affect the agrophysical indicators of fertility - aggregate composition, water strength, structural coefficient to the same extent. Moldboard tillage system causes the lowest density of soil in the cultivation of crop rotation in comparison with various resource-saving systems, as for the porosity of the soil, in most cases, these indicators of large values are marked by moldboard tillage. Resource-saving tillage systems significantly complicate the phytosanitary situation in the cultivation of crop rotation in comparison with the moldboard tillage system.

Based on the conducted research, experimental data were obtained that allowed recommending a calculation and balance method for determining fertilizer rates for constructing a fertilizer calculation system, which allowed obtaining the maximum yield of winter wheat (6.01 t•ha-1) after the forecrop peas on leached chernozem. The optimal combination of systems for fertilizing winter wheat after its forecrop peas with methods and techniques for placing mineral fertilizer in a 0-20 cm soil layer has been established.Obtaining high and stable yields with good quality of grain production of winter wheat, preservation and improvement of soil fertility, improvement of economic indicators in farms is impossible without the use of a rationally composed fertilizer system. It implies a reduction in doses of fertilizers, an increase in soil stocks of nutrients. Modern fertilizer systems should be based on biologicalization of agriculture, combined with the rational use of mineral and organic fertilizers, in relation to specific soil-climatic and economic conditions, taking into account the requirements of ecology and adaptive farming. Different methods and techniques of tillage affect its structural state, the structure of the arable layer, water-air, nutrient and thermal regimes, thereby affecting the growth conditions of plants, which affects their productivity.The main objective of the research was to determine the influence of fertilizer systems, methods and techniques of tillage on the food regime of leached chernozem and the productivity of winter wheat.The studies were carried out in an experimental crop rotation of the permanent study area located at the experimental station of the Stavropol State Agrarian University. The station is a longterm experience "Theoretical and technological bases of biogeochemical flows of substances in agrolandscapes", registered in the certificates record of long-term experiments of the GeoNetwork of the All-Russian Scientific Research Institute of Agrochemistry of the Russian Federation.

The article presents materials on the effectiveness of nitrogen fertilizers in the nutrition system for the winter wheat cultivation using no-till technology in the Stavropol Territory arid zone for 2017-2019. As a result of the studies, it was found that all the studied doses of mineral fertilizers relative to the control option (without fertilizers) on average increased the content of nitrate (by 0.9-10.4 mg / kg) and ammonia nitrogen in the soil (by 0, 2-6.7 mg / kg) during the vegetation phases. The urea ammonium nitrate (UAN) application using Duport liquilazer contributed to an increase in the nitrate and ammonium nitrogen content in the soil layer of 0-20 cm in all phases of the winter wheat development in comparison with similar experimental options in which nitrogen fertilizers were applied using a sprayer. According to the two years research results, a steady advantage of the intra-soil application of UAN using Duport liquilazer was noticed and the difference in yield, depending on the variant, was 0.15-0.25 t / ha. However, the more effective option was the introduction of UAN N20 autumn + UAN N87 spring + water-soluble organic substance 20:20:20 (2kg / ha) + water-soluble organic substance 20:20:20 (2kg / ha) Duport liquilazer, which allowed to obtain a yield of 4.66 tons / ha.

The relevance of the nitrogen fertilization is difficult to overestimate. Currently, winter wheat crops impose special requirements on nitrogen nutrition, as a rule, in early spring due to the unfavorable temperature conditions and excess moisture soil nitrification is suppressed. As a result, plants starve from lack of nitrogen and reduce the yield. At the same time, the variety represented on the nitrogen fertilizers market is able to satisfy practically any soil type in various conditions of wetting, and is limited only by the energy availability of agricultural producers. One of the factors, which have an impact on the effectiveness of nitrogen use, is the form of nitrogen-containing fertilizers. The experimental plots to study the influence of methods and technology of nitrogen fertilizer application in early spring on the winter wheat productivity were located in the arid zone of the south of Russia, where 350-400 mm of precipitation falls annually, the hydrothermal coefficient is within 0.6-0.8 units, and the soil cover is represented by dark chestnut and chestnut soils. The forecrop of the research period was winter wheat; the studied varieties of winter wheat are Yesaul and Nota. The seeder John Deere was usedfor the root fertilization in the experiment, and the Amazon spreader was used for the surface application. The analysis of the obtained data allows us to draw the following conclusions; the yield of the Nota variety was higher compared to the Yesaul variety on the fertilized variants by 0.15-0.28 t•ha-1. The highest productivity indicators are formed when fertilizing with the nitrogen dose of 52 kg•ha-1 application rateregardless of the fertilizer application method. The advantage of the root fertilization method is not reliable compared with the superficial method of applying manure. Studied doses and methods of nitrogen fertilizer application had a significant impact on the protein content in the grain of winter wheat.