A study has been conducted to determine how modern agriculture impacted the structure and reclomative state of light serazem soils 77 years after land development. In the first place, when analyzing soil survey materials, a change in the structure of the soil cover of light serazems is revealed. Long-term irrigation of light serazem soils causes grassing, which causes groundwater levels to rise. Due to these changes, serazem soils under the conditions of the new soil moisture regime acquired new features and properties that allow them to be assigned to another genetic group which is called the group of semi-hydromorphic serazem-meadow soils. As a result of irrigation, leaching, there are significant changes in the chemical, physico-chemical and agrotechnical properties of soils. This provision can be supplemented with materials that testify to the processes of salinization and desalinization of soils. Long-term irrigation and unregulated water intake in weakly soddy conditions leads to an increase in the level of groundwater, which causes a high intensity of the solonchak process and causes secondary soil salinization.

   In this study, analyzes were performed at various concentrations (3, 6, 9, 12, 15, 18, 21, 24, 30 %) of the H2O2 substrate to calculate the kinetic parameters of the soil catalase enzyme (Vmax, KM, Vmax / KM, KSEE, [S]opt and υ0,max). In order to calculate these parameters, the velocity values (v) were first calculated using the results of the analysis. Various models were then defined expressing the product-substrate relationship: [P] = f([S]). Further, according to the model selection criteria (R2, R2adj, σ, A, D, UII, AIC), the most suitable model was determined, reflecting the ratio [P] = f([S]). The initial speed in accordance with the established model was calculated by the formula: υ0=d([P])/dt│t=0. As a result of the study, it was found that salinity and alkalinity reduce the activity of catalase. As the substrate concentration increased, significant inhibition of the catalase enzymatic reaction was observed. The values of the coefficient of decomposition (KESS) of the enzymatic reaction are higher in saline soils, that is, inhibition of the formation of products is observed.

   In the course of the research, the general ecological conditions of the soil cover were determined, i.e. anthropogenic, pasture digression, degradation, landslides, erosion processes. On steep mountain slopes, loose areas with cliffs and rocky outcrops predominate. On the slopes of the studied objects, scree forms, in places – landslides. Erosion processes are developing at the studied objects, numerous erosion washouts formed by mudflows. There are many man-made, terraced pasture trails.

   The paper discusses biomorphological traits and productivity of the beet plant grown at different norms of potassium fertilizer under the conditions of Absheron. Organic and mineral fertilizers were found to affect positively both the biomorphological traits and productivity of beet. A Bordo-237 variety of beet was used as research material. To calculate the productivity index, the average value of the productivity of one plant was multiplied by the number of plants per hectare. In all variants, biomorphological traits and productivity were higher than those of the non-fertilized (control) variant. The number of leaves and the height of the plant increase with an increasing amount of potassium fertilizer. The indicators of three years were summarized and the mean value was calculated. Depending on the fertilizer norms, the weight characteristics of the above-ground part of the beet plant and the root were studied for years, and the mean value was determined. Besides, depending on the fertilizer norms, the characteristics of the length and diameter of the root vegetable of beet were also studied and evaluated. Studying the effect of potassium fertilizer on the productivity of the beet plant
(average over three years) showed the most productivity in the Background+N120P90K120 fertilizer (998.8 cwt/ha) variant, while the least productivity was observed in the control variant (productivity 528.7 cwt /ha). The reliability of the yield trait was tested using the T-test statistical software. According to all indicators, the results of the Background + N120P90K120 variant were superior and it was found to be the most optimal variant for growing beet under Absheron conditions.

   A scientifically based system of fertilizer application is the basis for the development of measures to improve soil fertility and crop yields. The objectives of these studies included the study of the effect of various doses of mineral and humic fertilizers on the accumulation of biomass, changes in leaf area, photosynthetic productivity and yield of melon crop on light gray soil of varying degrees of salinity in the Turkestan region. The results obtained showed that in the flowering phase, melon plants on a slightly saline background increased on average 0,7 t/ha of dry biological mass, while on a medium saline background this indicator was 0,2 t/ha lower. In subsequent phases of growth and development, melon significantly increased its biomass: in the phase of fruit formation and fruit ripening, it reached 1,9 and 3,0 t/ha on a slightly saline background, against 0,9 and 0,8 t/ha on a medium saline background, respectively. The maximum leaf surface of the melon plant was increased by the ripening phase. On average, on a slightly saline background, this indicator reached 16,7 m²/ha, and on a moderately saline background – 16,9 m²/ha. The highest photosynthetic productivity of melon plants was established between the flowering phase and the fruiting phase. On average, during the growing season, this indicator on a slightly saline background was 0,6 g/m² per day higher than on the medium salinity background. The greatest increase in the early yield was noted in the variants with the use of double doses of nitrogen, phosphorus and potassium in combination with the BioEcoGum preparation (N2P2K2 + BioEcoGum) – 86,7 %, and the combination of a triple dose of nitrogen with double doses of phosphorus and potassium (N3+P2+K2) made it possible to obtain 84,9 % of the increase in early melon production. The gross yield of melon varied from 13,1 t/ha in the control to 15,1-22,3 t/ha on a slightly saline background, and on a medium saline background it was 9,5 and 10,5-15,6 t/ha, respectively. Melon plants consumed significantly more nitrogen (61,9 % versus 56,1 %) for the formation of a yield unit on a medium saline soil than on a slightly saline soil. At the same time, increased salinity here reduced the absorption of phosphorus and potassium. In general, treatment 11 provided the highest gross income on both backgrounds of salinity, where double doses of nitrogen, phosphorus and potassium were used in combination with bioorganic fertilizer (N2P2K2 + "BioEcoGum") – 1784,4 and 1246,5 thousand tenge/ha, respectively. It was followed by the treatment 7 – N3+P2+K2 – 1725,0 and 1179,8 thousand tenge/ha and treatment 8 – N2+P3+K2 – 1710,5 and 1200,4 thousand tenge/ha, respectively.

   The article deals with the use of domestic liquid humic biological preparation «BioEcoGum» in the cultivation of grain and leguminous crops in the conditions of the south-east of Kazakhstan. Pre-sowing treatment of seeds with a solution of liquid humic biological preparation «BioEcoGum» increases the germination of plants by 10-30 %. Foliar fertilization of plants enhances the growth and development of plants, increases the grain yield from 14 to 80 %, contributes to an increase in the biomass of corn roots by 50 %; reduces the content of starch and gluten index, increases the protein and gluten content in the grain of winter wheat. According to the results of production tests, a liquid humic biological preparation containing macro and microelements necessary for plants is recommended for widespread introduction in the southern regions of Kazakhstan when cultivating winter wheat, barley, soybeans and corn for grain.