The article compares the theoretical models of fictitious and ideal soils. The dependence of the filtration coefficient on porosity and particle size is proposed. The correction for the shape of real soil particles and the physically bound water contained in it was calculated for the studied types of sapropels and mixtures based on them.

The article considers the experience of studying the drainage capacity of drainage on poorly permeable mineral soils according to the data of domestic and foreign scientists. The natural conditions of the studied objects and the applied drainage designs are characterized. The main reasons for the unsatisfactory operation of drainage and the factors causing them are noted. The most effective measures and constructive solutions for drainage systems are given, which increase their performance in difficult natural conditions on heavy soils. It is recommended to use this research experience in the development of drainage structures, taking into account changing natural conditions, using modern, more technological construction methods and new materialsl.

 The effect of an electroactivator whose interelectrode space is separated by a diaphragm has been analyzed. The dependence of the resistance in the chambers at different water temperatures has been established. The comparison of experimental and theoretical values of resistances is given.

In 2019‒2021, in the central part of Belarus, studies were conducted on the derno-podzolic consolidated loamy soil with three maize hybrids (DN Piviha – FAO 210, Polessky 202 – FAO 230 and DN Galatea – FAO 250), cultivated at a plant density of 70, 90, 110 and 130 thousand/ha, two terms of sowing and harvesting with a differ-ence of 2 weeks. The biochemical composition of maize plants and its morphological parts was studied, which made it possible to identify the following patterns. The stems have the lowest fat content (1.0 %), the cobs have the highest fat content (3.6 %), with an average accumulation of it in plants of 2.3 %. The ash elements are respectively 1.6 % in the cob, 6.9 % in the leaves and 4.0 % in the plants. Protein is less in the stems (3.6 %), more in the cob (8.7 %) and on average in the plant contains 6.7 %. Fiber is less in the cob (7.5 %), more in the stems (36.2 %), in the plant – 23.0 %. The nitrogen-free extractive substances is less in the leaves (49.5 %), more in the cobs (78.8 %), in the plant – 64.0 %. Weather conditions of the year are the most significant factor affecting the change in the biochemical composition of plants and some morphological parts of maize.

Over the course of 11 years, the productivity of the herbage of plant communities in the floodplain meadows of the river was evaluated. Sozh. A decreasing series of herbage productivity can be represented as follows: Caricetum gracilis > Deschampsia cespitosa > Poo-Festucetum pratensis > Agrostis vinealis. The most stable in terms of productivity is the Caricetum gracilis association. To assess the influence of meteorological factors on the productivity of the herbage, the hydrothermal coefficient was calculated. The values of the hydrothermal coefficient varied from 0.99 to 1.60. Significant correlations between the hydrothermal coefficient and vegetation productivity have been established. The content of radiocesium in the herbage did not exceed the existing standards. 

A method for diagnosing the provision of soils with a form of the nitrogen that is potentially assimilated by plants has been proposed for wide use in production as the basis for innovative technologies for the use of nitrogen fertilizers. Grades for the provision of soddypodzolic soils with potentially assimilable nitrogen and for the need for agricultural crops in nitrogen fertilizers for the planned yield, for basic application and top dressing of plants, for correction factors for fertilizer doses have been elaborated. Application of doses of nitrogen fertilizers differentiated by fields given the data on the content of Nst in soils ensures an increase in the yield of grain crops in comparison with the basic technology up to 6–10 kg/ha and payment for 1 kg of fertilizer nitrogen by 1.7 times with a decrease in losses by 17–24 and saving fertilizer nitrogen up to 20 kg/ha of a. i., reduction of mineralization of organic substances by 12–26 % and loss of soil humus.

The calculation of the elements of water balance of the soil under perennial grasses was carried out according to the data obtained at the experimental site of the irrigation complex «Tushkovo» (Belarusian State Agricultural Academy) with a soil surface slope varying within 0.023‒0.027. The smallest error was obtained when calculating the water consumption of perennial grasses according to the maximum air temperatures and biothermal coefficients established on the basis of the physical principle «balance of cause-andeffect interactions in a closed physical system», independent of the method of grass stand use (green mass, haylage, hay, pasture). The analysis showed that with given indicators  of surface slopes, surface runoff should be taken into account only at the top of the slope and at a distance along the slope of up to approximately 50 m. In areas located down the slope, surface runoff, as a consumable element of the water balance, can be neglected when cultivating perennial grasses. This limitation is explained by the fact that during rain (or irrigation), about the same amount of water inflowing from the higher part of the slope additionally infiltrates into the soil, as it decreases with surface runoff down the slope.