The review of modern technical means of non- destructive diagnostics of hydraulic structures of land reclamation systems is presented. In accordance with the current technical normative-legal acts of the Republic of Belarus the possibility of introducing information technologies in the process of inspection of structures and their parts, in particular, the use of optical and digital method – photogrammetry, as a universal, operative, low- cost and safe way of diagnostics and fixation of hydraulic structures conditions is considered.

The issues of substantiating the possibility of using vertical drainage on reclamation sites with certain hydrogeological conditions were discussed, the most important of which is the good water permeability of an aquifer with a thickness of at least 15 m from the surface. The characteristic of Pripyat Polesje as the most favorable region with such conditions was given, the natural water resources of which allow the use of renewable groundwater in agricultural production, including for land irrigation. On the basis of the data of the Institute of Geological Sciences of the National Academy of Sciences of Belarus, a schematic map of the zoning of the Pripyat Polesje according to the conditions for the use of drainage and humidification systems of vertical drainage was compiled. Technical and economic indicators of the cost of construction of these systems, horizontal drainage systems and an open drainage network are given. The most significant advantages and disadvantages of vertical drainage systems and the obvious prospects for its use in modern natural conditions are characterized.

Mathematical modeling of the dependence of sugar beet yield on the level of nutrition and moisture content was performed on the basis of the physical principle of cause-and- effect interactions (causal interaction) in a closed physical system using data from variety testing stations (Kobrin, Molodechno, Nesvizh) and a variety testing site (Shchuchin). The reference indicators of the mathematical model of the dependence of sugar beet yield on nutrition factors and moisture supply have been established. The necessity of supplementing the method of variety testing of agricultural crops with the control of atmospheric precipitation and air temperatures directly in the territory of cultivation of crops is noted.

Data on the technical condition of drainage collectors of reclamation systems made of asbestos-cement and reinforced concrete pipes of large diameter (0.3–0.6 m) with a service area of 87–94 hectares have been given. Collectors were examined after 7 and 47 years of their operation, the condition of the inner surface of the pipes, the amount of siltation and the reasons for it have been determined. The low quality of construction has been revealed, during which the displacement of pipe joints and their poor sealing have been allowed. However, the studied collectors are operable even with the existing condition. Therefore, it is possible to use large-diameter polymer pipes with sealed connections at reconstruction facilities instead of separate open channels.

The general natural and ecological state of the Salyan steppe has been analyzed. The purpose of the study in the course of studying the actual reclamation state of irrigated gray-meadow soils under cotton and grain crops is to determine, along with the degree of salinity, the type of salinity and salinity of soils according to generally accepted methods. It has been found that the amount of SO₄ in groundwater at the experimental site is 1.08–1.09 g/l; Cl ion 7.0–9.59 g/l; CO₃ – 0.03–0.05 g/l; HCO₃ – 0.29– 0.32 g/l; Ca – 0.08–0.50 g/l; Mg – 0.01–0.22 g/l. The amount of salts varied from 9.23 g/l to 11.22 g/l.

The purpose of the paper is to determine the current state of irrigated soils of the Kura-Araz lowland for cotton and grain crops. Studies have been carried out in the experimental area near Seyidsadykhly (area 2.5 hectares). The amount, composition and types of soils have been determined; their productivity has been studied. The results of the analysis have showed that the amount of salts in the 0–100 cm soil layer used for cotton and cereals was 0.22–0.39 and 0.00, 18–0.48 %, respectively. The types of salts of these soils in terms of the total number of Cl ions and the ratio of Cl:SO₄ are sulfate-chloric. During the study period, the productivity of cotton was 30–35 c/ha, grain – 28–30 c/ha. The pH has been determined to vary between 7.12 and 7.71.

In the conditions of sloping soils of Poozerie, the maximum yield of alfalfa variable – 105.5–108.1 kg/ha of dry weight – on average for two years, was formed in the middle of the slope on drained slightly washed sod- podzolic gleevate, light loamy soil with the introduction of PK + Nanoplant – Co, Мn, Сu, Fe. On slightly soiled sodpodzolic cohesive sandy soil (the top of the slope), the increase in yield from fertilization was 12.6 %, and with an increase in their dose was 6.1 %. The proportion of alfalfa variable in the harvest was high and amounted to 83.9–87.9 %, and fertilization practically did not change its content in the herbage. At the top of the slope, the net photosynthesis productivity of alfalfa changeable in the third year of life was 37.5 % higher on average during the growing season than in its middle. The value of the net productivity of photosynthesis without fertilization increased from the first mowing to the third. At the top of the slope, when fertilizing, its value decreased by 27.0–43.6 %.

In the conditions of sloping soils of Poozerie, the maximum yield of alfalfa variable – 105.5–108.1 kg/ha of dry weight – on average for two years, was formed in the middle of the slope on drained slightly washed sod- podzolic gleevate, light loamy soil with the introduction of PK + Nanoplant – Co, Мn, Сu, Fe. On slightly soiled sod- podzolic cohesive sandy soil (the top of the slope), the increase in yield from fertilization was 12.6 %, and with an increase in their dose was 6.1 %. The proportion of alfalfa variable in the harvest was high and amounted to 83.9–87.9 %, and fertilization practically did not change its content in the herbage. At the top of the slope, the net photosynthesis productivity of alfalfa changeable in the third year of life was 37.5 % higher on average during the growing season than in its middle. The value of the net productivity of photosynthesis without fertilization increased from the first mowing to the third. At the top of the slope, when fertilizing, its value decreased by 27.0–43.6 %.