1. SOIL RESOURCES AND THEIR RATIONAL USE 
Based on the improved general agro-production grouping of soils, the assessment of soil fertility in the Mstislavsky district and their erosion, the degree of suitability of soils of arable land in the region for the cultivation of grain crops (winter rye, winter and spring wheat, winter triticale, spring barley and oats) was established: the most suitable, suitable, unsuitable, unsuitable. The areas of suitable soils for the cultivation of grain crops, as well as the possible areas for their sowing, taking into account the alternation in crop rotations, have been identified, and a reserve of sown areas of grain crops in the region has been established. The results of the research can be used in the development of measures for the rational use of land resources and for improving the structure of sown areas of grain crops, taking into account the current state of the soil cover.
The possibilities of using infrared thermal images with a spatial resolution of 100 m obtained by the Landsat 8 survey system for soil interpretation are shown. On the example of key plots of arable and forest lands, the influence on the formation of the thermal field of soils of arable lands of their granulometric composition, degree of moisture content and content of organic matter is demonstrated, for forest lands – types of forest vegetation and its projective cover.
Perennial leguminous grasses reduce yields on sod-podzolic slightly washed soils by an average of 14 % compared to non-eroded soils, on medium and heavily washed soils – by 20 and 25 % respectively. Depending on the developing hydrothermal conditions of the growing season, the decrease can reach 30 %. Under the same soil-geomorphological conditions, the alfalfa of the north reduces the yield to a greater extent compared with the eastern galega and meadow clover.
Perennial legume-cereal grasses reduce yields on sod-podzolic medium-washed soils by an average of 11 %, on heavily washed soils – by 19 %. Annual legume-cereal grasses reduce yields on sod-podzolic slightly washed soils by an average of 10 % compared to non-aerated soils, on medium and heavily washed soils – by 18 and 25 % respectively. Annual grasses to a greater extent reduces the yield on sod-podzolic soils on moraine loams compared to soils on loess-like loams.
2. SOIL FERTILITY AND FERTILIZATION
The results of multi-year research to assess the impact of fertilizer systems and the effect of residual amounts of phosphorus and potassium introduced with mineral and organic fertilizers in the preceding period on the balance of nutrients and fertility of medium-cultivated sod-podzolic loamy sand soil in article are presents.
It was established that application of N80P37K95 at high productivity of cultivated crops (59,6 cfu/ha) was insufficient for maintaining the achieved level of soil fertility with negative balances of mobile forms of phosphorus (–14 kg/ha) and potassium (–50 kg/ha).
The exclusion of a particular nutrient element from the fertilization system for a long period contributes to the intensification of degradation processes in the soil, causing the loss of humus by 0,19–0,53 % for the 20-year period of the study, with annual losses of mobile phosphorus and potassium of 1,0–3,6 and 2,6–8,3 mg/kg of soil.
The article presents data on the effectiveness of liquid nitrogen-sulfur fertilizers (1999–2000, 2010–2011, 2016, 2018–2020) on sod-podzolic soils of different granulometric composition (light loamy, loose-sanded) in Gomel, Minsk and Grodno regions in the cultivation of agricultural and vegetable crops. It is shown that the use of liquid nitrogen-sulfur fertilizers, for crops demanding sulfur, provides an increase in yield, while improving the quality of products.
In field experiments conducted on sod-podzolic soils, it was found that 35 years after the Chernobyl accident, the largest share of 137Cs is in a strongly bound form, which determines the low transfer of 137Cs into crops. The share of easily available 137Cs forms (water-soluble + exchangeable) for plants is 10,9 % in sod-podzolic sandy soils – 5,1 % in sandy loam and – 3,9 % in loam of the total content in the soil. The share of easily available of 90Sr forms (water-soluble + exchangeable) is 67,2 % in sod-podzolic sandy soils 59,5 % sandy loam and 75,5 % loam of the total content in the soil. This fact determines the high transfer of 90Sr into crops. The research results show that for the studied crops there is a significant increase in the transfer of 90Sr to plants from sod-podzolic sandy loam soil in warmer and drier growing seasons. It can be noted that with the warming of the climate on the territory of radioactive contamination, the problems with high transfer of 90Sr into crops will worsen.
The results of study of phosphorus nutrition of spring wheat on highly phosphatesupplied soil are presented. The high ability of the soil to satisfy the plants' need for phosphorus has been established. The main factor determining the availability of soil phosphates, phosphorus accumulation in plants and grain productivity was moisture supply. The strongest curvilinear correlation (R2 0,36) between available phosphate content in soil and water content in soil 0–20 cm layer was observed. Concentration of total and mineral phosphorus in plants had reliable curvilinear relation with water content in soil 0–50 cm layer – R2 0,72 and 0,37 respectively.
In the field technological experience on highly cultivated sod-podzolic loamy soil, the agroeconomical efficiency of different fertilization systems of winter wheat, depending on the method of basic tillage, was studied. It was found that the sealing of straw without a compensating dose of nitrogen, both with traditional and surface tillage, did not have a negative effect on the uniformity of seedlings and the development of winter wheat plants. Due to the use of fertilizers in a block with traditional tillage, the yield of winter wheat grain increased by 31 % on average and the protein and gluten content significantly increased, i. e. fertilizers provided food grain along with an increase in yield. In the block with surface tillage, the yield was on average 4,6 c/ha higher compared to similar options in the block with traditional tillage.
In recent years, wheat has been grown on 221 million hectares of land around the world, and the total yield is 769 million tons as a result of modern intensive technologies. Foliar feeding of wheat with various components of macro- and microelements, along with the saving of basic mineral fertilizers applied to the soil, increases the efficiency of their assimilation by the plant, increases yield and improves grain quality. In our experiment, we studied the effect of the timing and rates of foliar application of winter soft wheat on the technological quality of the plant. Although the highest indicator was observed when there was a high agrophone and top dressing in each phase of the growing season, it was found that the optimal level can be achieved for all of the above indicators with a single top dressing of leaves before the appearance of flag leaves, with a 2-fold decrease in mineral fertilizers. The practical results of the work are that in conditions of light gray soils when fertilizing for winter wheat in the amount of 50 % (NPK 90:45:30 kg/ha) of the amount of traditional norms (NPK 180:90:60 kg/ha), as well as when using liquid suspension preparations enriched with macro- and microelements of various components, the effect of saving mineral fertilizers, increasing the yield and quality of grain was determined. Feeding winter wheat with suspensions of various components during the autumn tillering phase, during the formation of the flag leaf and after heading had a positive effect on the natural grain weight (42,9; 43,7; 36,8 g/l) and the amount of protein in the grain (1,2; 1,2; 1,1 %) in comparison with the control.
The results of field experiments on specially prepared 4 levels of exchangeable magnesium content in the podzoluvisol loamy soil in a wide range of (Mg 45–240 mg/ kg) are presented. The parameters of soil and plant diagnostic for sulfur and magnesium supply of winter triticale had been developed. The range of the optimal exchangeable magnesium content Mg 140–155 mg/kg of soil and the equivalent ratio of cations (Ca2+ : Mg2+ = 4–5 and K+ : Mg2+ = 0,6–0,7) had been found. The obtained results could be used for the choice of the appropriate fields for triticale grain yield of 70 t/ha and more, as well as to identify the need for foliar spray of plants with solution of MgSO4 ∙ 7H2O according to the analysis of soils and plants in the early stages of their development.
The most agronomic and economic effective use of N60+30+30P60K120B0,10Zn0,15 in combination with foliar dressing of plants growth stimulators twice on the background of 60 tons/ha of cattle manure was for maize growing for green material it was found In a field technological experiment on sod-podzolic loamy sand soil. Such a system of fertilization with savings of 90 kg/ha of mineral fertilizers, provides 14,7 t e., collecting protein 36,3 kg/ha, the conditional profit – 14,6 USD/ha and 4 % of profitability. Each kilogram of mineral fertilizers provides compensation of 45 centners of green mass of maize, the cost of the increase of 1 ton of nutritional unit amounts to 77 USD/ha. This fertilization system maintains the achieved level of mobile phosphate content and restrains the rate of loss of mobile potassium compounds of the soil.
The research results about sod-podzolic sandy loam soil liming on crop yield and nutrient accumulation in the corn green mass are presented. The data of nutrient removing by the corn yield are showed. It is considered the nutrient balance and its intensity using dolomite flour, defecate and carbide lime ameliorant. The research results show the possibility of using calcium-containing industrial wastes for the liming acidic soils. This technique reduces the ameliorants production and transportation costs.
The paper contained the results of the data on the impact of various forms of sulfurcontaining mineral fertilizers on productivity of winter and spring rapeseed and fatty acid composition of oil. It has been etstablished that sulfur-containing fertilizers application resulted in the increase of oil yield and improvement of production quality (fatty acid composition).
The article presents the results of field studies on the effectiveness of magnesium sulfate in sunflower crops. It was found that the combined application of boron fertilizer Intermag Boron and magnesium sulfate in three foliar top dressing and Pictor fungicide once against the background of N126P60K210 increases the yield of sunflower seeds by 11,8 centner/hectares. The oil content of seeds increased by 2,3 %.
As a result of generalization of field experiments and analysis of data obtained during route surveys in the regions of the Republic of Belarus, the average content of trace elements in the main and by-production of agricultural crops in various places of growth was determined, the limits of variation depending on their species composition were established.
In field experiments on sod-podzolic soils low- and medium-provided with trace elements, high efficiency and manufacturability of the use of liquid micro-fertilizers MicroStim with a stimulating effect in the cultivation of agricultural crops has been established. Significant increases in the yield of grain and vegetable crops, rapeseed, buckwheat, potatoes and strawberries were obtained.
In a field experiment on sod-podzolic, highly cultivated, light loamy soil, the effect of foliar fertilizing of winter wheat with ADOBE micronutrients on the accumulation of trace elements in plants by growth and development phases at different levels of mineral nutrition was established. It has been established that foliar fertilizing with ADOBE micro-fertilizers has a positive effect on the accumulation of trace elements in plants and structural parts of winter wheat.
The article presents the results of research on the effectiveness of the use of liquid micro-fertilizers MicroStim in the cultivation of winter rapeseed on sod-podzolic highly cultivated light loamy soil. It has been established that foliar top dressing of plants with various brands of micronutrients MicroStim increases the yield and oil content of winter rape seeds and is an economically justified technique.
Screening of zonal isolates Bacillus sp. By cultivation on solid and liquid nutrient media with different sources of carbon and phosphorus at background of increasing concentrations of glyphosate resulted in the determination of perspective target objects, which are capable of metabolization herbicide glyphosate as a sole P-source. Screening showed that potassium mobilizing rhizobacteria Bacillus sp. Virtually not capable of glyphosate utilization as sole carbon source for metabolism.
In studies in a model experiment, it was found that in the process of weathering saponite-containing basaltic tuffs, mainly cations K, Ca and Mg are washed out and some alkalinization of the solution occurs.
In the process of weathering of glauconite, both alkaline and alkaline earth cations K, Ca and Mg, and acid cations Al and Fe actively pass into the solution, which leads to acidification of the solution.
Differences in the weathering processes of saponite-containing basalt tuffs and glauconite should be taken into account when they are used as agromeliorants in biocenoses.
The article provides a review of the scientific literature on the use of silicon-containing preparations in agriculture, including: a brief history of the use of silicon-containing preparations in agriculture, the effect of silicon on plants, soil fertility, silicon status of soils. The types of silicon preparations are given, conclusions are drawn from the review of scientific literature.
