На основі результатів польових і аналітичних досліджень встановлені оптимальні для Західного Полісся дози та види вапнякових меліорантів і добрив для збереження родючості дерновопідзолистого зв'язано-піщаного ґрунту і одержання стабільної урожайності ріпаку озимого. З'ясовано вплив удобрення (N 120 Р 90 К 120), сірчаних добрив, позакореневого підживлення мікродобривом, різних доз і видів вапнякових меліорантів на морфологічну структуру рослин ріпаку озимого та їх продуктивність. Найвищу урожайність ріпаку (2,94 т/га) забезпечило внесення 1,5 дози (Н Г) доломітового борошна на фоні рекомендованої дози мінеральних добрив (N 120 Р 90 К 120)-приріст урожаю до контролю (без добрив) становив 2,09 т/га, до фону (N 120 Р 90 К 120)-1,60 т/га. Застосування сірчаних добрив (S 40) і дворазове позакореневе підживлення посівів мікродобривом Нутрівант Плюс олійний (2 кг/га) зумовили збільшення урожайності ріпаку озимого на 15,6 %.

Topicality. Today, the search for ways to accumulate organic carbon and restore soil fertility, as well as increase crop yield, is a topical issue for the sod-podzolic soils of Western Polissia. Purpose. To determine the intensity of CO2 emission and the organic carbon balance on sod-podzolic soil at different fertilizer rates in the maize-soybean link against the background of chemical amelioration with incorporation of by-products. Methods. We used such methods as a stationary field trial, comparative and calculation method to determine the accumulated and emitted CO2 by plants, analytical and calculation methods to determine the organic carbon balance. Results. The CO2 emissions from organic matter mineralization amounted to 5.01–5.45 t/ha by the recommended fertilizer rate and calculated by the normative method on the background of dolomite and limestone powder, which was 23.4–34.2 % higher than the control (without fertilizers). The CO2 emission into the atmosphere through plant mass mineralization, depending on fertilization and chemical amelioration, was in the range of 18.6–24.7 t/ha and exceeded the control (without fertilizers) and the background of 1.0 Hh (hydrolytic acidity) CaMg(CO3)2 by 1.2–2.0 times, which is associated with improved soil conditions, higher by-products mass and CO2 accumulation by plants. The highest amount of CO2 was accumulated by maize (64.8–65.0 t/ha) and soybean (15.0–15.8 t/ha) at combination of the fertilizer rate calculated by the normative method with microfertilizers on the background of dolomite flour. The application of calculated fertilizer rates on the background of 1.0 Hh CaMg(CO3)2 provided an advantage in the formation of organic carbon in the soil, which formed a positive balance of 0.12 and 0.15 t/ha. In the variant without fertilizers and chemical amelioration, the ratio of total CO2 emissions into the atmosphere per 1 t of grain yield in the maize-soybean link was 4.65 and 4.62 units, while the application of the fertilizer rate calculated by the normative method against the background of 1.0 Hh CaMg(CO3)2 decreased to 3.78 and 3.89 units, respectively. Conclusions. For increasing the maize and soybean productivity on sod-podzolic loamy sandy soil, incorporation of plant mass into the soil with applying the fertiliser rates calculated by the standard method against the background of 1.0 Nh CaMg(CO3)2 is an effective method to control soil degradation that ensures the inclusion of additional organic carbon into the cycle, which is aimed at its fixation by forming a deficit-free balance of 0.12 and 0.15 t/ha. Key words: emission, organic carbon, productivity, fertilization, land amelioration, plant mass

Assessment of the state and changes forecast of balances of humus and nutrients under the influence of anthropogenic factors, in particular fertilizers which are the criteria for environmental monitoring is given in the article. At the same time, the introduction of an environmentally friendly fertilizer system should ensure the economic efficiency of growing crops on a par with the preservation of soil fertility. The aim was to study the influence of the system of winter wheat fertilization on the balance of humus and nutrient elements on sod-podzolic soil and to establish the economic efficiency in research’s variants. The fertilizer system includes variants with amelioration a 1,0 dose of dolomite flour by the hydrolytic acidity (Hh), mineral fertilizers N120Р60K90 with addition of sulfur S40 and microfertilizer Nutrivant Plus Cereals (2 kg/ha) in foliar application. Methods of research were field trials, calculation, comparative and statistical analysis. Research’s results. Ploughing of plants by-products of back into soil is a source of organic carbon and nutrients. The yield of winter wheat straw in the variants changed from 2.04 to 4.47 t/ha. The largest amount of root (1.27 t/ha) and surface (1.47 t/ha) residues were provided by application 1.0 dose CaMg(CO3)2 and N120Р60K90 with the addition of S40 and microfertilizer Nutrivant Plus Cereals. The above fertilizer system provided a positive humus balance of 1.39 t/ha. The difference of data in variants with and without straw showed that due to straw ploughing in the soil accumulated up to 27–31% of the relative values of the newly formed humus. Optimization of the nutrition conditions due to fertilizers and liming caused an increase uptake of nutrients by culture, which together with unproductive losses led to a decrease of elements balance. At the same time, an increase the elements removal occurred at indicators of the intensity of NPK balance above 100%. This allowed us to conclude that the winter wheat fertilization of N120Р60K90 with the addition S40 and microfertilizer in combination with 1Hh dose of dolomite flour provides extension of sod-podzolic soil fertility along with increasing economic profitability of wheat cultivation. In this case, the grain yield of 3.85 t/ha contributed to the highest (1.52 UAH/ha) payback of fertilizer and liming.

The influence of cultures in short-rotation crop rotation of Western Polissia on the ecological component of sod-podzolic cohesive-sandy soil by the analyzing the balances of nutrients and humus is shown and an economic assessment of their cultivation is given. The most accessibly and fairly objective a complex assessment of certain crops impact on the ecological state of the soil can be carried out by their contribution to the formation of balances of humus and nutrients. In article used the results of researches obtained in a field stationary experiment with winter wheat, maize for grand, spring barley and winter rape for 2012–2020 years. To assess the impact of cultures on the balances formation was chosen variant with the recommended rate of mineral fertilizers on the background of 1.0 Ha (hydrolytic acidity) dose of CaMg(CO3)2 (dolomite flour). It has studied that the supply of nutrients with plant biomass is a powerful source of their recycling. In particular, the highest content of nitrogen (3.56 and 2.75%) and phosphorus (0.95–0.99%) was obtained in rapeseed and winter wheat, while by-products showed the accumulation of potassium (1.52 and 1.39%) respectively. Taking into account the obtained results, the influence of growing crops on the formation of nutrient and humus balances was determined. It was established that by liming and fertilization with the return to the soil of by-products biomass of the studied crops was formed a positive balance of nitrogen in the range of 29.6–43.4 kg/ha, phosphorus 23.0–54.9 kg/ha, potassium 71.6–99.8 kg/ha. Only with the application of N120 under maize for grain was obtained nitrogen deficiency of –47.5 kg/ha. Due to crop residues and by-products of the studied crops, a positive balance of humus was determined: winter wheat 0.73 t/ha, corn for grain 2.17, spring barley 0.40 and winter rape 0.11 t/ha. The economic component of the technology of studied crops growing showed that the largest net profit was achieved for marginal crops: maize for grain (19.8 thousand UAH/ha) and winter oilseed rape (14.4 thousand UAH/ha). Due to the restrictive effect of other factors, primarily moisture supply, the system of fertilizing winter wheat and spring barley did not create conditions for the realization of the planned yield, which led to low profitability of their production.

Topicality. With climate change, agricultural production accounts for about 15 % of green-house gas emissions. Disbalance of organic carbon decreases the environmental sustainability and productivity of agroecosystems and soil fertility. With soil management, the intensity of carbon monoxide emission from the soil can reduce to optimize its organic matter. Issues. There is a crucial need to study and analyze comprehensively the effects of different rates of chemical meliorants and mineral fertilizers for crops in the Western Polissia crop rotation on the volume of CO2 emissions from sod-podzolic soil. Aim. To study the characteristic features of carbon dioxide emissions from sod-podzolic soil during winter wheat and spring barley cultivation with different rates of meliorants and fertilizers. Materials and Methods. Field experiment, agrochemical and statistical methods. Results. On the background of mineral fertilization, land reclamation with limestone materials at 0.5 and 1.0 rates determined by the hydrolytic acidity of the soil generally decreases CO2 emissions into the air. During the growing season, depending on the development stage of spring barley, the level of carbon dioxide emission in the variant with N90P90K90 was 89.8–68.3–63.5 mg CO2/kg soil, and in combination with 1.0 rate of dolomite powder – 83.1–59.8–63.6 mg CO2/kg soil. It is noted that the intensity of CO2 accumulation in the surface layer depended on rates of ameliorant, soil moisture and temperature. Thus, the carbon dioxide emission in a winter wheat field was the highest when 1.5 rates of dolomite powder were applied on the background of N120P60K90 , and in the stem elongation stage at air temperature 13.2 ℃ was 77.7 mg CO2/kg of soil. When air temperature increased to 22.0 ℃ in the heading stage, this indicator increased by 1.2 times and at air temperature of 20.4 ℃ in the full maturity stage, it decreased by 1.3 times. When 1.0 rate of dolomite powder was applied, CO2 emission decreased to 18.2 mg CO2/kg of soil compared with 1.5 rates in the full maturity stage of wheat due to the intensity of redox processes in the soil when different rates of limestone materials was applied. Conclusions. In the short-term crop rotation, lime application had a positive effect on the for-mation of deficit-free balance of organic carbon in sod-podzolic soil with intensive application of mineral fertilizers for crops. When we applied 1.0 and 1.5 rates of dolomite powder on the background of N120P60K90 in winter wheat crops, the organic carbon balance was 0.35–0.28 t/ha, in spring barley crops on the background of N90P90K90 – 0.10–0.16 t/ha. Key words: winter wheat, spring barley, land reclamation, fertilizers, carbon dioxide, balance.