The article analyzes the results of the assessment of soil fertility in agricultural lands of Belarus by administrative districts: a cartogram has been compiled, and a grouping of areas has been carried out according to the soil fertility score. The correlation coefficients of the yield of grain crops with soil fertility scores were established, which showed high reliability of the modern assessment of agricultural land in Belarus.

The article presents acid-alkaline buffering capacity evaluated of sod-pale-podzolic light loamy soils as a result of the cultural process of soil formation. The areas of buffering of examine soils in the acid and alkaline ranges as compared with the buffering capacity of quartz sand were determined is shown. A qualitative assessment of soil buffering is given on the basis of the scale of natural acid-alkaline buffering. The obtained data of buffer capacity of soils can be applied for assess the functional state of the soil absorbing complex and the degree of soil resistance to anthropogenic influences.

The change in the structural-aggregate composition and indicators of anti-erosion resistance of sod-podzolic light loamy soils depending on the genesis of the soil parental material and the degree of manifestation of the processes of erosion degradationare analyzed in the article.

When irrigated for 11 years with good quality waters from the Dniester of carbonate heavy loamy chernozem, changes in the composition of primary and clay minerals were established. They were expressed in a noticeable decrease in the content of both groups of minerals and in the relative accumulation of quartz in the soil. Among the primary minerals, layered silicates were the first to be destroyed, among clay minerals - smectite and chlorite. Signs of transfer of smectite by profile and accumulation in horizon B, as noted by other researchers, have not been established. Indicators of changes in the mineralogical state indicate that the upper part of the irrigated chernozem, along with quartz, receives additional enrichment with illite.

The balance of minerals of the silicate part of carbonate chernozem irrigated for 11 years with good quality waters compared to non-irrigated carbonate chernozem revealed a decrease in the content of primary minerals by 56 t/ha, smectite by 267 t/ha, chlorite and kaolinite in the sludge in total by 55 t/ha. Irrigation caused additional illitization of the upper part of the profile of chernozem and an increase in the amount of illite by 56 t/ha. Loss of smectite occurred on the spot without moving it deep into the profile. Natural (before irrigation) carbonate chernozem contains signs of loss of primary and clay minerals in the volume characteristic of ordinary chernozem, which probably indicates its ancient origin and a low level of carbonates in the past.

It was revealed that for the accumulation of nitrogen reserves of mineral compounds in the soil when grown without fertilizers, the best sideratom was spring and sweet clover, and buckwheat for increasing the content of mobile compounds of phosphorus and potassium. The same pattern was traced when applying mineral fertilizers. At the same time, most of the nutrients in the soil before sowing winter wheat accumulate when all the fertilizers are applied (N₈₀P₄₀K₄₀) directly under the green manure, or only part of it - N₄₀P₄₀K₄₀ and N₄₀P₄₀. It was established that when applying for N₈₀P₄₀K₄₀ and P₂₀K₂₀ siderats for winter wheat, a grain yield of wheat at the level of 7,1-7,5 t/ha was formed depending on the crop that was used for green fertilizer. The introduction of the dose of N₈₀P₆₀K₆₀ directly under the winter wheat, both after siderate and against the background of pure steam, led to a decrease in yield by 33-47 and 11-15 %, respectively.

The article is devoted to decide an important scientific problem of modern soil science, it consists in the development of a spatially-differentiated system of arable soil quality management on the basis of improving of methodological approaches to soil rating, value determination and agro-investment attractiveness, scientific substantiation and practical implementation of differentiated agricultural technologies accounting the heterogeneity of the arable soils properties. It was developed a scheme of a spatially differentiated system of arable soil quality management. It was described in detail the functions of the main constituent parts of the information, analytical, assessment and management parts of the presented system.

The article discusses the methodology of determination and character of the profile distribution of carbon dioxide concentration in the air of sod middle podzolic gleyic sandy soil on waterborne and glacier sediments of Polissya of Ukraine. It has been shown that the differentiation of carbon dioxide concentrations in soil air depends on P (total), moisture content (P water), and depth of measurement. It has been established that the range of values of CO₂ concentration in soil air at depths 10, 20, 30, 40, 50 cm is 5636, 4219, 4743, 6903 and 7989 mg/m³, respectively. It was found that the total mass of СО₂ and organic carbon in soil air of sod-podzolic glued suppository soil on winter-winter wheat winter ice and winter ice compartments is 8,783 and 2,396 kg/ha, respectively.

A comparative assessment of the influence of traditional and organic production on the crop productivity of crops, crop quality indicators, soil fertility and economic efficiency is given.

The comparative analysis of agroeconomic efficiency of new compost on the basis of brown coal with traditional analogue on the basis of peat in field experiment on sod-podzolic sandy loam soil has been carried out. The introduction of coal-manure compost in the dose of 60 t/ha contributed to obtaining the productivity of the crop rotation link is 146.1 kg of fodder units/ha, which is equivalent to the influence peat-manure compost (149,9 kg of fodder units/ha). The use of compost under the condition of extraction of brown coal directly for its production is unprofitable. The lowest loss (24 USD) was obtained when composting on the basis of brown coal waste remaining after its use for industrial purposes, when they were delivered from brown coal deposits to the farm at a distance of up to 5 km. The introduction of coal-manure compost provided a deficit-free balance of humus and mobile forms of Р₂О₅ in the arable layer of sandy soil, but not enough to maintain К₂О at the initial level (-10 mg/kg), which is similar to the effect of peat-manure compost on agrochemical indicators.

On sod-podzolic light loamy soil with very high phosphorus maintenance and potassium the high cost efficiency of introduction in a crop rotation of N_330-630 is established. The greatest efficiency and delay of degradation of fertility is reached at application of N₆₃₀P₉₀K₁₉₅ against the background of 50 t/hectare of manure. The efficiency of use of phosphoric and potash fertilizers in low doses (P_15-20K_30-60) is established that promotes increase in stability of efficiency in years with adverse weather conditions.

The article presents the results of studies assessing the impact of fertilizer systems, weather and soil conditions on yields, carrying and compensation factors for the removal of nutrients by spring barley on sod-podzolic light loamy highly rich mobile forms of phosphorus and potassium. The optimal fertilizer system is the complex application of nitrogen at a dose of N₉₀₊₃₀ (main and additional feeding), P₂₀K₄₅ against the background of manure (60 t/ha), which provides an increase of 28,6 t/ha or 82 % of control, contributes to stabilization yield by years (CV = 16 %). Under adverse weather conditions in the formation of barley yields, the participation of fertilizers increases (up to 51, of which nitrogen is up to 44 %). With an optimal fertilizer system, the specific nitrogen removal rate averaged 17,7; phosphorus - 10,2 and potassium - 18,5 kg/ton of basic with the corresponding amount of by-products. For the studied soils, the optimal recovery factors for the removal of nutrients by the crop of fertilizers are: N - 1,1; Р₂О₅ - 0,3 and К₂О - 0,4.

The article presents data on the effect of new forms of liquid nitrogen-potassium and solid fertilizers on productivity and quality indicators of perennial grass mixtures and lucerne in the cultivation on sod-podzolic loamy soils of the Minsk and Vitebsk regions and sod-podzolic sandy loam soil of the Minsk region. The positive effect of liquid nitrogen-potassium fertilizers has been established when used for the first and second grass mowings of the first, second and third year of use against the background of the introduction of phosphate fertilizers (cereal and legume-cereal grass mixtures) and complex fertilizers (lucerne), ensuring an increase in productivity and improvement of hay quality.

The application of N_60-80 herbs under the first cut rates not significantly increase the intake of¹³⁷Cs in plants. The second nitrogen fertilization of herbs in rates of 40-60 kg/ha increases the accumulation of the radionuclide in the hay of second-cut grass with respect to the phosphorus-potassium backgrounds. Nitrogen fertilizers on the background of P₉₀K₁₅₀ lead to a slight increase in the transfer factor of¹³⁷Cs to perennial grass when they are applied in doses of 120-140 kg/ha. At the same time, on a higher background of the use of potash fertilizers (P₉₀K₁₈₀), the radionuclide transfer factor into hay and with higher rates of nitrogen fertilizers (N_120-140) rates not exceed 0,30-0,31. On peaty-gley soil, when phosphorus and potash fertilizers are applied in rates of Р₉₀К_150-180 and nitrogen fertilizers in rates of N_100-140, perennial grass grasses can be cultivated without restrictions on the contamination density of¹³⁷Cs (up to 40 Ci/km²) for hay production when using it for fodder for receiving whole milk and meat meeting the republican regulatory requirements for the radionuclide content. For the production of meat with¹³⁷Cs content up to 200 Bq/kg, regulatory clean hay of the first mowing can be obtained using nitrogen fertilizers at a rate of 100 kg/ha with a soil contamination density of 38,0-40,0 Ci/km², and at doses of 120-140 kg/ha against Р₉₀К₁₅₀ with a density of up to 33.5 Ci/km², against a background of Р₉₀К₁₈₀ with a density of up to 38 Ci/km².

The evaluation of the efficiency of mineral fertilizers at the cultivation of реа on sod-podzolic loamy soil with different content of exchangeable magnesium in the soil was carried out. It was found on control plots without fertilizers the yield was increased on 26 % in the range of Mg content 46-147 mg/kg of soil. Further increase of Mg content in soil up to 198 mg/kg was excessive; it followed by reduction of grain yield on 3,5 %. The crude protein content in the pea grain was positively influenced by fertilizers as well as by the increasing levels of soil magnesium supply. Maximal yield response 1,88-1,94 t/ha to basic NPK treatment and response to foliar spray of Mg fertilizer with 60 kg S was noted on low content of exchangeable Mg 46-50 mg/kg in soil with total net return of 157,2-162,6 USD/ha with a profitability of 101,5-101,9 %. Efficiency of NPK and Mg fertilizer treatments were strongly reduced on the plots with high level of Mg soil supply.

With loads of liquid animal waste for 26 years, the content of mobile forms Zn, Cu and Mn increased throughout the profile of sod-podzolic soils under the biogenic-accumulative nature of the distribution, while maintaining the main trends established for soils without loads. In sandy soil (liquid manure of cattle 100-200 t/ha) the increase in the content of mobile forms of Cu in genetic horizons was 10-27 %, Zn - 12-49 %, Mn - 6-40 %; in sandy loam (pig manure effluents 500-600 t/ha) - 30-100 % Cu, 40-219 % Zn, 25-85 % Mn; in loamy (liquid manure of cattle 900-1000 t/ha) - 50-200 % Cu, 79-414 % Zn, 35-162 % Mn. By migration intensity heavy metals are arranged in a row: Zn > Cu > Mn.

In field experiments conducted on sod-podzolic loamy sand soil, close negative correlations between the content of mobile potassium in the soil and the accumulation of¹³⁷Cs by plants were found. The efficiency of saturation of the soil potassium in the discrimination of¹³⁷Cs is much higher on soils with low potassium content. The minimum biological availability of radio caesium is observed for spring wheat and barley in the range of 413-419 ppm, spring rape - at 454 ppm, potatoes - at 465, corn - at 432 ppm, timothy grass - at 412 ppm, clover - 506 ppm, alfalfa - 437 ppm and arctic clover - at 327 ppm of mobile K₂O content in the soil.

In the field experiments conducted on sod-podzolic loamy sand soil (Podzoluvisol) сlose negative correlations have been found between organic matter content and¹³⁷Cs и⁹⁰Sr accumulation by forage crops. The humus content at which the minimum accumulation of¹³⁷Cs is noted for corn - 3,15 %, timothy grass - 3,24 %, clover - 2,92 %, alfalfa - 2,86 %; the minimum accumulation of⁹⁰Sr for clover - 3,17 %, corn - 3,06 %, alfalfa - 3,62 %; timothy grass - 3,34 % and аrctic clover - 2,11 %. The most intensive decrease in radionuclides in plants with an increase in the content of humus in the soil is observed from 1 to 2,5 %

In the field experiments conducted on sod-podzolic loamy sand soil (Podzoluvisol) сlose negative correlations have been found between the exchangeable acidity of the soil (pH) and⁹⁰Sr accumulation by crops. The intensity of the acidity neutralization effect on the reduction of the⁹⁰Sr transfer to plants is higher at lower pH values. The minimum biological availability of⁹⁰Sr for grain crops was noted at pH 6,82-6,90, rapeseed - 6,62, corn - 6,78, timothy grass - 6,30, clover - 6,52, alfalfa - 6,50, lupine - 6,09, аrctic clover - 6,43 and potatoes - 6,84.

The incrustation of millet seeds with copper on the background of mineral nutrition N₉₀P₆₀K₉₀ makes it possible to obtain an increase in grain from the small seed variety Galinka at the level of 3,2-5,2 c/ha and from the large seed variety Druzhba 2 - 2,0-2,8 c/ha, with the largest its value is ensured by the use of a chelated form of a trace element. As a result, the grain yield on the Galinka variety was 44,0 c/ha with a payback period of 1 kg of NPK 8.8 kg of grain, and on the Druzhba 2 variety - 46,5 c/ha and 8,2 kg, respectively.

The article presents the results of studies to assess the effectiveness of the use of nitrogen fertilizers and Disolvin ABC complex microfertilizers on winter wheat crops. It was established that in the cultivation of winter wheat after clover, the greatest economic effect was obtained when nitrogen was applied at a dose of N₆₀₊₆₀ with a single use of Disolvin ABC (0,2 l/ha) in the flag leaf phase (DK 37-39).

Antagonistic activity of zonal rhizobacteria strains A. brasilense и B. circulans in respect of pathogenic fungi was tested in series in vitro experiments. It was shown that nitrogen-fixing and potassium mobilizing PGPR are capable of biological control of pathogenic fungi F. poae, F. oxysporum и F. graminearum.

In the article, on the basis of generalization of the results of our own and other authors of scientific studies, the expediency and ways of increasing the resistance of grain crops to adverse environmental conditions are substantiated.