Loss Of Humus Research Articles

Indicators of soil fertility of typical chernozem after prolonged use of various fertilizer systems

The research was carried out in order to study the effect and aftereffect of various fertilizer systems on the main indicators of fertility of typical chernozem. The work was carried out in a long-term field experience in the grain crop rotation in the conditions of the Belgorod region. The soil of the experimental site is typical medium–sized low-humus heavy loam chernozem on loess-like loam. The scheme of the experiment provided for the study of the effect of mineral fertilizers, in doses of N64P64K64 and N128P128K128; organic fertilizers with crop rotation saturation of 8 and 16 t/ha of the crop area (s. p.) and combinations of organic and mineral fertilizers. Three methods of basic tillage were analyzed: plowing, non-tillage and minimal tillage. During six rotations of the five-field crop rotation, without the use of fertilizers, humus losses amounted to 0.06…0.27 %, with an actual content of 4.96…5.15 %; the content of mobile phosphorus decreased by 2.8…9.2 mg/kg, and was at the level of 47.6…51.2 mg/kg; and mobile potassium remained almost at the same level (108.4…116.2 mg/kg). To obtain the optimal content of the main nutrients in the soil, it is necessary to use an organomineral fertilizer system. In particular: the use of mineral fertilizers in doses of N64P64K64 or N128P128K128 for a background of 8 t/ha of bovine manure (cattle). At the same time, the humus content in these variants reached the maximum value and amounted to 5.30…5.64 %, mobile phosphorus 222.6 …255.1 mg/kg and mobile potassium 156.6…173.5 mg/kg. Or long-term use of cattle manure with a crop rotation saturation of 16 t/ha. At this level of fertilization, the humus content was 5.34 % (on average according to the method of basic tillage), phosphorus and potassium 122.0 and 143.3 mg/kg, respectively.

Dynamics of the Humus State of Southern Chernozem with Prolonged Use of Mineral Fertilizers in the Conditions of the Steppe Volga Region

The results of monitoring the dynamics of humus and total nitrogen of the southern chernozem in a long-term stationary experiment with the use of mineral fertilizers are presented. In the first 3 rotations of the grain-to-crop rotation, intensive mineralization of humus was noted in all variants of the experiment. In the conditions of grainsteam crop rotation, this process slowed down, and in the variant with the use of minimum doses of nitrogenphosphorus fertilizers in the 6th rotation, the accumulation of humic substances was revealed. The maximum decrease in humus content at the end of 8 rotations of crop rotation (more than 48 years) was observed in variants with the introduction of medium and high doses of nitrogenphosphorus fertilizers. The use of a minimum dose of fertilizers best compensated for the loss of humus of the southern chernozem during prolonged agricultural use. In comparison with the initial data, negative changes in the qualitative composition of humus were noted in the experiment, expressed in a decrease in the proportion of humic acids. At the end of the 8th rotation, the total nitrogen content in the soil decreased in all variants of the experiment.

Проблемы опустынивания в восточной зоне Ростовской области

The article presents an analysis of the dynamics of soil fertility, trace elements, pH, aridity index and normalized index. Salt lakes in the complex from 30-50 % occupy 68.3 thousand hectares. The humus content in the arable layer is low. There is a decrease in the content of humus (from 2.2% to 1.7%) and phosphorus (from 18.6 mg/kg to 18.2 mg). The content of exchangeable potassium is generally within the optimal range. The processes of loss of humus and nutrients in the soils of the area are a manifestation of the desertification process. The content of sulfur and trace elements (copper, zinc, manganese, cobalt) is low, insufficient for grain crops. The soils of the district are slightly alkaline (pH – 8.1). The aridity index of the Zavetinsky district is 0.41, and the normalized index is 0.59. According to the normalized aridity index – 0.59, the territory of the Zavetinsky district belongs to the moderately arid (NIA =0.5—0.6). Keywords: DESERTIFICATION, SALT LAKES, ARIDITY INDEX, SOIL FERTILITY, TRACE ELEMENTS

Processes of humus loss in leached chernozem soils of the North Kazakhstan region

This article discusses the processes of dehumification and loss of humus in leached chernozem soils of agricultural lands of the North Kazakhstan region due to mineralization and as a result of erosion processes. Modern rates of soil dehumification lead to a decrease in the fertility of agricultural land and a decrease in yields, soil fertility is a valuable resource. The intensive process of decomposition of organic matter and its dehumidification occurs as a result of plowing virgin soil and as a result of its improper use in agricultural conditions. In the North Kazakhstan region, after the development of virgin lands, trends of intensive soil dehumidification are widespread. It was found that the object of study, leached chernozem, loses 0.69 t/ha by mineralization of humus and 0.011 t/ha as a result of erosion processes. Due to the long-term agricultural use of the land, improper construction of soil protection works, lack of organic substances that complement the humus composition of the soil, the balance of humus is disturbed, and organic substances connect soil structures with each other, increasing resistance to environmental factors. The destruction of soil structures of the plowed soil layer, the predominance of dust structures, thinning of the humus layer and the intensity of erosion processes were revealed.

Decrease in fertility of typical chernozem due to long-term anthropogenic pressure in grain-beet crop rotations

The saturation of sugar beet rotations under different fertilizer application systems and long-term cultivation induces significant changes in soil properties, leading to decreases in humus content, mineral nitrogen, phosphorus, and potassium. The study was conducted in a stationary multifactorial experiment in grain-beet crop rotations: crop rotation, row-crop, and grain-row crop rotations with the application of 40 t/ha of manure under sugar beets + NPK 100:90:90 and a variant without fertilizers. The paper presents the results of monitoring changes in humus content during each rotation, reduction of humus reserves in the plow layer, and physicochemical and agrochemical soil indicators. In the variants without fertilizers, we observed 0.24–0.41% decline in humus content in all crop rotations during 3 rotations of ten-field crop rotations (30 years). Overall, there occurred 0.89–1.00% decrease over 50 years of anthropogenic influence, equivalent to 31.8–35.7 t/ha, or 23.1–26.1% of initial reserves per hectare. Despite application of 40 t/ha of manure + NPK 100:90:90 under sugar beets, humus loss was 27.5 t/ha in the row-crop rotation and 16.8 t/ha in the grain-row crop rotation. Fertilizer application led to increase in exchangeable and hydrolytic soil acidity. With the application of 6.7 t/ha of manure + NPK 53:42:42 per 1 ha of crop rotation area, there was a tendency towards increase in mineral nitrogen content, mobile phosphorus doubled to 280.1–302.8 mg/kg compared to the variant without fertilizers, and exchangeable potassium decreased regardless of the fertilization system, which was associated with its utilization by plants. Sugar-beet yield increased to 44.76 t/ha in the crop-rotation under the organo-mineral-fertilizer application system, exceeding the spring wheat rotation by 4.63 t/ha and the variants without fertilizers by 2.45–2.72 times. Therefore, the modern fertilizer application system under sugar beets did not ensure stabilization of humus content in the soil and increased its acidity. It is necessary to more broadly use cover crops in crop rotations, incorporate crop residues, and apply biological preparations to improve soil fertility.

Theoretical substantiation and development of ecologically friendly farming system in Ukraine

Intensive farming has caused soil degradation, including the loss of humus, soil structure breakdown, compaction, and a decrease in both potential and effective fertility. Therefore, research into farming systems is highly relevant. In this regard, the purpose of this study is to scientifically substantiate, develop, and implement an ecologically friendly modern farming system under Ukrainian conditions. The primary methods used to determine the effectiveness of various farming systems and ensure the accuracy and reliability of experimental data were field, laboratory, and statistical methods. The study substantiated that an industrial farming system with the input of approximately 12.0 tonnes per hectare of crop rotation area of organic matter (8.0 tonnes per hectare of manure and 4.0 tonnes per hectare of plant residues) produces about 0.81 tonnes per hectare of humus, although 1.33 tonnes per hectare of it is mineralised, leading to a negative humus balance in the soil. The output of grain units in this system is 8.21 tonnes per hectare, feed units – 9.63, and digestible protein – 0.86 tonnes per hectare, with stability at 91.2% and profitability at 88.0%. The organic farming system, which includes the use of 24 tonnes per hectare of organic fertilisers and biological products to control weeds, diseases, and pests in agrocenoses, does not ensure a positive humus balance in the soil (-0.14 tonnes per hectare) and has significantly lower productivity. The no-till system, which involves the application of 12 tonnes per hectare of organic fertilisers in the form of root and stubble residues, by-products of crop production, and mineral fertilisers during sowing and foliar feeding, ensures a positive humus balance (+0.12 tonnes per hectare) but has productivity levels comparable to the organic system. The ecological system provides stable, economically viable, and resource-adequate productivity of arable land, enhances the quality indicators of products, and preserves and restores soil fertility. It increased the output of grain units by 8.9%, feed units by 7.2%, and digestible protein by 8.1%, ensuring high stability at 94.1% and an increase in production profitability by 8.5% compared to the control. The materials in this study are of practical value for agricultural enterprises of various ownership forms and will serve as technological guidelines for the implementation of modern, ecologically safe, economically and energetically justified agricultural production

Dynamics of humus in field crop rotations on drained lands

The purpose of the research is to study the influence of different types of field crop rotation, fertilizers, drainage and hydrothermal conditions on the dynamics of humus in reclaimed soil. The studies were carried out on the experimental fields of the All-Russian Research Institute of Reclaimed Lands (reclamation sites “Kuzminskoye Boloto 2”, “Semenovskoye” and “Gubino” in the Tver region). Waterlogged soils were drained using closed drainage (inter-drain distance is 18–20 m, drain depth is 0.9–1.2 m). The soils of the experimental plots are soddy-podzolic, light loamy, gleyic, formed on a moraine or thin binomial. Observations of the dynamics of humus were carried out in the grain-grass-row, grain-grass, grain and grain-row types of crop rotation. The influence of crop rotation on the content of humus in the soil was determined, first of all, by the composition, the structure of the crops grown and agricultural technology of their cultivation. Due to plant residues, 56.6–76.5 % of the volume of mineralized humus were restored in grain-grass-row crop rotation, 51.8 % in grain, 26.4 % in grain-row crop rotation. The most significant qualitative changes in the composition of humus were observed in grain-grass-row crop rotation: with a positive humus balance, the ratio of humic and fulvic acids increased from 0.63 to 0.74. The use of organic and mineral fertilizers significantly changes the balance of humus in the arable layer of the soil. With an organic-mineral fertilizer system, the annual loss of humus (in kg/ha) on the drained plot was 6.8–11.4 times less, on the non-drained plot – 2.1–2.6 times less than in the variant without fertilizers. Drainage of waterlogged soils increases the role of fertilizers in the accumulation of humus, reduces its losses and improves the quality parameters of humus – the ratio of humic and fulvic acids in the composition of humus under the influence of drainage increased from 0.61 to 0.88. The impact on the dynamics of humus of hydrothermal conditions has been established. In years with a dry first half of the growing season, an increase in humus content is observed; in excessively wet years, on the contrary, a decrease is observed. The correlation coefficients of humus content with hydrothermal conditions in May-June were – 0.84 (in 1985–1993) and 0.95 (in 2014–2022).

Effect of Fertilizer, Furrow Length, and Irrigation Flow Rate on Soil Nutrient and Yield of Apple Orchard

The objective of this study was to evaluate the impact of furrow irrigation with a length of 96, 144, and 192 m and a flow rate of between 0.2 and 0.4 Ls−1 on the leaching of nitrogen, phosphorus, and humus from dry subtropical soils in Azerbaijan. Moreover, the impact of six fertilizer levels, namely, control (without fertilizer), 10 t ha−1 of cow manure, N90P90K90 + 10 t ha−1 of cow manure, N120P90K90 + 10 t ha−1 of cow manure, N120P120K90 + 10 t ha−1 of cow manure, and N120P90K120 + 10 t ha−1 of cow manure, on the performance of apple orchards, has been examined. The findings indicate that the brown soils of the irrigated grassland exhibit normal humus, total nitrogen, and weak phosphorus levels, with a gradual decline observed in the lower layers. Applicable to the agricultural and subsurface layers, the aggregates are 0.25–1.0 mm in diameter, with an agricultural value of 12.9% and 21.8%, respectively. This indicates a poor structural condition of the apple orchard soil. The elevation of the water flow rate from 0.2 to 0.4 Ls−1 resulted in a greater extraction of humus, nitrogen, and phosphorus from the soil. Both water flow rates increased the nutrients and humus leaching from the soil. By extending the furrow length to 192 m, the losses of humus (3.25%), nitrogen (0.36%), and phosphorus (0.30%) from the soil in both water flows significantly increased in comparison to the 96‐m length. By extending the length of furrows to 192 m, the yield (21.97 t ha−1) was significantly reduced in comparison to the 96‐m length (22.31 t ha−1). As a consequence of the application of N120P90K120 + 10 t ha−1 of cow manure, the yield of 27.3 t ha−1 was significantly elevated in comparison to other fertilizer treatments and the control treatment (17.9 t ha−1). Therefore, management of fertilizer systems, furrow length, and water flow can improve soil fertility and plant yield by reducing erosion in the meadow‐brown soil of Azerbaijan.

The state of natural resources of the West Kazakhstan region (1990s – early 2000s)

The purpose of the study was to analyze the state of natural resources in the West Kazakhstan region during the 1990s to the early 2000s. The ecological condition of the region’s natural resources remains one of its most pressing issues, necessitating regular monitoring. Analysis of official data sources revealed that the socio-economic development of the region coincided with the establishment and operation of large industrial and construction enterprises, leading to adverse effects on the region’s natural environment. Monitoring of arable land in areas with dark chestnut soils indicated a continued loss of humus during this period. Presence of nitrates and high permanganate oxidizability suggested the presence of organic compounds linked to the decomposition of heptyl rocket fuel. Disease patterns indicated that populations in the southern areas of the region experienced high chemical burdens alongside radiation exposure. Furthermore, the article addresses concerns regarding the state of forest resources and wildlife, with authors highlighting a significant risk of natural resource contamination by industrial waste from heavy industries in the region.

Intensity and Direction of Dynamics of Soil Fertility Indicators in Landscape Farming

The purpose of the work is to study the dynamics of soil fertility indicators after the development of adaptive landscape farming systems in the most eroded region of the Belgorod region since 1981. Based on 40 years of research at the model object “Turnip Log”, it is shown that the direction and intensity of the soil-forming process is changing. Four stages are distinguished: at the first until 1993 the decrease in humus content and alkalization of the soil environment, characteristic of washed away carbonate soils, continues; at the second stage, the rate of humus loss drops 10 times; the third ten-year period is characterized by a significant increase in organic matter and its stabilization subsequently, which accompanied by a transition in pHsol. to the area of neutral values. The dynamics of mobile forms of macroelements and agronomically valuable cations Ca2+ and Mg2+ indicate the cultivation of soils in general. At the same time, it is emphasized that there are no universal elements in the agricultural system; Along with the creation of an ecological framework of protective plantings, it is necessary to comply with the principles of adaptive placement of agricultural crops and a deficit-free balance of humus and nutrients in crop rotations.

Effects of Agricultural Cropping Systems on Soil Water Capacity: The Case in Cross-Border Altai

Temperate grasslands are called the breadbaskets of the world. Due to most continental climate conditions, humus-rich soils have been developed. These soils are very well suited for grain production. This is why extensive conversions from natural steppe to arable land have been implemented in this biome. The Kulunda Steppe, in Southwest Siberia and Central Asia, occupies large parts of the driest regions of the Eurasian Steppe Belt. It was one of the sites of the Virgin Land Campaign realized in the former Soviet Union in the 1950s and 1960s. Intensive agricultural practices have caused significant soil degradation, mainly through humus loss and soil erosion. This results in the degradation of organic carbon, altering the physical and chemical structure of the chestnut soils and impacting their water storage capacity. Against the background of climatic changes, a further intensification of these processes and conditions is to be expected. To stabilize soil carbon and optimize moisture utilization, it is necessary to extensively introduce worldwide experiences in conservation cropping technologies (such as no-till, min-till, and direct seeding) in the area. This study aimed to determine the effects of different cropping systems on soil water storage and water availability. The study’s initial hypothesis was that the soil conservational cropping system has advantages against the traditional deep tillage (24 cm). This hypothesis was based on extensive global experience studying the effects of different agricultural management systems on soil-water balance. In 2013–2016, an experiment was conducted for the first time in the Kulunda steppe to instrumentally measure soil moisture and matrix potential at 30–60–120 cm depth under traditional and conservation technology using innovative meteorological and soil hydrological stations. Statistically significant advantages of no-till over deep tillage (24 cm) in terms of moisture retention were found, confirming the hypothesis of this study. Besides, this groundbreaking study reveals new possibilities for soil monitoring in the region. The acquired data are applicable for predictive models using remote sensing. Moreover, the results on the management effects for the soil water balance provide basic approaches to soil water monitoring, offering important data for evaluating model results and remote sensing products for the region.

Effectiveness of early fallow on Steppe chernozems

Topicality. Clean fallow is a reliable means of drought control, increasing productivity and sustainability of Steppe agriculture. At the same time, a fallow remains the most vulnerable field of the crop rotation, which requires perfect methods of maintenance that can counteract erosion processes, prevent humus losses, and improve the moisture availability of wheat. Purpose. To determine the soil protection and agrotechnical effectiveness of early fallow (sunflower, stubble, maize) when growing winter wheat in the conditions of the Northern Steppe of Ukraine. Materials and methods. The primary tillage of clean fallow was carried out with heavy cultivators, combined units, and plows. The erodible resistance of chernozem was assessed by field modeling and hydrological methods, to frost heaving – by soil lumpiness and the amount of post-harvest residues. The water-physical properties of the arable layer were determined in accordance with generally accepted methodical recommendations, the yield – by direct harvesting, and the grain quality – in accordance with DSTU 3768:2019. Results. It was established that maintaining arable land according to the early fallow scheme contributes the soil deflation and erosion control. At the same time, the migration of fine soil outside the field does not exceed 1.5–4.3 t/ha per year. The introduction of early fallow after cereals and row crops contributes to additionally accumulate productive soil moisture in the amount of 130–150 m3/ha compared to the control (plowing 25–27 cm) and restore moisture reserves for the spring tillering of wheat plants (207–221 mm or 86–92 % of the ultimate field water capacity, 0-150 cm layer). On sloping lands, the two-phase tillage of early fallow is preferable, which includes strip loosening to 40–45 cm depth in late autumn and shallow loosening to 14–16 cm depth in spring. In terms of productivity of winter crops, early fallows are not inferior to fall tillage. On the plains, the best variant of fallow maintenance was variant, which combines mulching with the cultivation of cover crops, on the slopes – with soil slitting. When involving all by-products of predecessors in the cycle, it is advisable to feed plants with nitrogen fertilizers in the spring with a dose of N30-60. The application of mineral nitrogen provided an average wheat yield on early fallow at the level of 5.52–6.66 t/ha and food grain with a protein content of 11.5–11.9%, gluten - 22.6–24.6%. Conclusions. Maintaining arable land according to early fallow scheme reliably protects the soil from erosion and ensures the restoration of productive moisture reserves to the level of 86–92% of the ultimate field moisture capacity in the second year. According to the wheat grain yield, spring tillage (12–16 cm) was not inferior to autumn plowing (25–27 cm). The effectiveness of early fallows is enhanced by soil slitting, cultivation of post-harvest (cover) crops, optimization of nitrogen nutrition of plants. Key words: early fallow, winter wheat, tillage, post-harvest residues, fertilizers, erosion, moisture, yield, grain quality

ИЗМЕНЧИВОСТЬ И ЭКОЛОГИЧЕСКОЕ СОСТОЯНИЕ РИСОВЫХ ПОЧВ РОСТОВСКОЙ ОБЛАСТИ (НА ПРИМЕРЕ РИСОВОЙ СИСТЕМЫ ООО «МАНЫЧ-АГРО»)

Purpose: to study the soil properties in the rice system at Manych-Agro LLC, to determine their variability in the space of rice paddies and to assess the ecological state of soils. Materials and methods. On a representative plot, the groundwater table level (GWL), water-physical and physico-chemical properties of soils under different crops of rice crop rotation were studied. Soil samples in non-irrigated plots were also taken for comparative analysis (sunflower, winter wheat and alfalfa). Results. It was revealed that the soils in the arable layer of rice system of Manych-Agro LLC are characterized mainly by weak salinity, gypsum-bearing layers in depth. There is practically no alkalinity, but magnesium alkalinity prevails in the absence of sodium one and low content of exchangeable calcium in the soil absorbtion complex (SAC) in the 40-cm layer (from 60 to 72 % of the total SAC). The humus content is low to very low. The above mentioned negative properties of soils contribute to their strong compaction. Variability of soil properties indicators in space is different. The most significant soil variability was found in salinity (V = 103 %) and solonetzization of soils (V = 25...40 %), and insignificant – in exchangeable calcium (V = 10 %). Humus has an average variability (V = 16 %) for rice fields. Conclusions. The ecological state of soils is ambiguous. Exceeding the GWL, loss of humus and the increase in the proportion of magnesium in SAC characterize the situation as an ecological disaster, and an increase in soil compaction and a decrease in the amount of exchangeable calcium form an emergency situation. A relatively satisfactory situation is emerging in terms of soil salinity and exchangeable sodium.

Comparison of agrophysical parameters and humus content in the soil of virgin and arable land

Topicality. Currently, there is an urgent need to address the following challenges: loss of soil humus content, deterioration of soil agrophysical properties, reduction of the impact of soil agrophysical degradation, restoration and preservation of fertility. Purpose. Comparison of agrophysical parameters and humus content in the soil of virgin and arable lands and development of scientific recommendations on the formation of favourable agrophysical properties and regimes of chernozems to suspend the development of degradation processes in the soil and preserve fertility. Material and Methods. The study of ordinary chernozem was carried out in the virgin lands and experimental plots of the Erastivka Research Station of the Institute of Grain Crops of NAAS of Ukraine during 2010–2016. We studied: total humus content; structural and aggregate composition of the soil; soil structure coefficient; soil density; water resistance of agronomically valuable structural aggregates. In May, soil samples were selected at equilibrium density after mechanical tillage. Sampling was carried out from the soil profile at intervals of 5 cm, to a depth of 0–200 cm in quadruplicate according to DSTU 4287. Results. It was found that deterioration of agrophysical properties (structural and aggregate state, density, water resistance) and reduction of humus content and thickness in the humus horizon in comparison with virgin soil occurred as a result of long-term cultivation of ordinary chernozem. Conclusions. When comparing the properties of ordinary chernozem of arable land with virgin soil, we find that they are significantly degraded. Significant loss of humus and structure degradation leads to an increasing soil density and a partial loss of the ability to resist degradation. To preserve and sustainably use arable chernozems, an improved farming system should be implemented, with scientifically based crop rotations, the latest soil protection technologies, and the proper amount of organic and mineral fertilisers to increase the humus content as its main components. Key words: ordinary chernozem, soil degradation, humus content, structural and aggregate state, density, water resistance

SPATIAL AND TEMPORAL FEATURES OF DEHUMIFICATION OF CHERNOZEMS OF THE PRYDNISTERSKA UPLAND

Purpose. In the structure of the soil cover of the Prydnisterska upland, the area of chernozems is 4 060 km2. The overall rate of plowing up of the territory reaches 80%. The agricultural use of chernozems led to the transformation of almost all processes and properties, but these changes were most reflected in the humus state. A decrease in the intake of organic matter and an increase in its mineralization led to an active manifestation of dehumification. Therefore, the study of this problem will provide a scientific basis for effective fertility management, analyze the current state and propose measures to restore the ecological stability of chernozems at the regional level. The purpose of the research is to characterize the dynamics of the humus content in the chernozems of the Prydnisterska upland during the industrial period (from the beginning of the 20th century to the present), as well as to analyze the extent of the manifestation of dehumification of chernozems in flat and slope areas. To achieve this goal, the following were carried out: the field stage of work on the selection of soil samples, laboratory analytical studies of the humus content, analysis of data from archival materials and the results of preliminary studies on the relevant topic. The object of the research comprises typical chernozems and podzolized chernozems of the Prydnisterska upland. The subject of the study is the humus content of the arable horizon (0–20 cm) of chernozems of flat and slope relief with varying degrees of erosion. Data & Methods. The study of the problem of dehumification of chernozems of the Prydnisterska upland was carried out using generally accepted methods: comparative-geographical, comparative-analytical and comparative-profile. Archival materials of soil science expeditions, statistical data of preliminary agrochemical surveys and our own research results obtained during 2019–2020 (research sites “Savyntsi», «Ruda», «Basivka» and «Kadyivtsi») were used for a comparative analysis of the dynamics of the humus content in chernozems over the last century. Results. Analysis of the data on the humus content in the chernozems of the Prydnisterska upland during the industrial period, at different times, confirmed the active manifestation of dehumification. The intensification of agriculture in the region, neglect of soil protection technologies and insufficient application of organic fertilizers have led to the formation of a negative humus balance. For 106 years (from 1914 to 2020), the humus content of the chernozems of the Prydnisterska upland has decreased by 30–45%. The most intense losses of the organic component have been recorded by the beginning of the 90s of the 20th century. The total loss of humus by chernozems during this period amounted to 36–48 t/ha. According to the accepted estimates of the humus content, the chernozems of the study area in modern soil management conditions are characterized as low-humus with a humus content (3–4%). Statistical data indicate that the intensity of dehumification has decreased over the past 6 years, but the negative humus balance remains. Losses of humus (in the 0–20 cm layer) decreased to the level of 0.28–0.36 t/year, however, these data are correlated depending on the structure of crop rotations, soil cultivation technologies and fertilization rates. According to the results of the study, it has been found that the variability of the humus content within the arable horizon (0–20 cm) increases with a change in the morphometric parameters of the relief and the intensity of manifestation of erosional degradation. In particular, a critical situation is observed on slopes with a steepness of 5–6 °, which are distinguished by the lowest reserves of humus. Dehumification of chernozems of the Prydnisterska upland is the result of an unbalanced anthropogenic impact. Optimization of this problem requires the widespread introduction of soil protection technologies on slope areas of the relief, the introduction of an appropriate amount of organic fertilizers, sowing green manure crops, conservation of eroded areas.

INFLUENCE OF DEFICIT FERTILIZER SYSTEMS ON THE DYNAMICS
 OF PHOSPHATE AND POTASSIUM CONTENT AND THEIR
 BALANCE IN LONG-TERM EXPERIMENTS ON SOD-PODSOLIC
 LOAMY SAND SOIL

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.

Темно-сірі опідзолені гумусово-деградовані ґрунти на лесових островах (опіллях) Чернігівського Полісся: стан і перспективи відновлення

Goal. To study the recreational influence of oak vegetation on the prospects of restoring fertility and natural properties of dark gray podzolized humus-degraded soils. Methods. Expeditionary field, morphological-genetic, comparative-analytical, agrarian-analytical. Results. Dark gray podzolized soils with humus-degraded lightened arable layer were described for the first time. They were ignored during the survey of the soil cover of Ukraine, although the arable part contains 20–30% less humus than in the sub-arable layer. These soils are very leached, strongly acidic, and unsaturated with the bases (50–60%). Partial restoration of the lightened layer under the influence of the oak forest belt is shown. Conclusions. It is fixed that dark-gray podzolized soils occur among the dark-colored soils with humus-degraded horizons in the Polissya loessial islands. The primary cause of humus losses in the arable land is its instability to mineralization in conditions of good moisture, enhanced aeration, and activation of microbiological activity.

Оценка агроэкологического состояния агроландшафтов для повышения их устойчивости

Introduction. Agricultural land use organized in the dry steppe Kulunda of Altai Krai, with an area of more than 1,8 million hectares, is unsustainable. This is due to many factors, but the main ones are agro-climatic conditions (temperature and precipitation), as well as anthropogenic elements of landscapes, as a result of the joint manifestation of which erosion processes develop. The purpose of the study: to conduct a multicomponent analysis of agricultural lands in the dry steppe Kulunda Altai Krai to optimize their agro- and geo-ecological state, as well as increase the sustainability of agricultural landscapes. Research methods: a systematic approach and a comparative geographical method used in the processing of materials characterizing the qualitative and quantitative indicators of agricultural landscapes and the analysis of zonal physical and geographical characteristics of the territory. Relationships and mutual influences within anthropogenic landscapes have been studied using the ecological-landscape approach. Research results. Over a thirty-year period of monitoring the heat and moisture supply of the territory, it was found that only 1-2 years per decade are optimal for growing crops (spring wheat), and agricultural land prevails in the structure of the land fund (seven municipal districts), and their share varies from 47 % to 96 % in Uglovsky and Tabunsky districts, respectively. Examining the structure of sown areas and crop rotations, it was found that arable land is the most common agricultural land, it accounts for more than 70 %, pastures – almost 20 %, hayfields and fallow lands – 8,5 %, perennial plantations – only 0,04%. It was determined that cultivated crop rotations lead to degradation of the soil cover, which occurs due to active dehumification – the loss of humus reserves in the process of deflation and active mineralization on fallows and fields with tilled crops. It was calculated that the rate of humus loss on an area of one hectare is 0,24 tons per year. Conclusion. The calculations made show that the coefficient of environmental stability is much lower than the threshold, and a relatively high indicator of environmental stability in the Mikhailovsky and Uglovsky districts was achieved due to the tape forest and salt lakes located on their territory, which do not have a positive impact on the sustainability of agricultural areas. Improving the sustainability of agricultural land use is possible with the organization of a grass field system by changing the structure of sown areas and crop rotations.

ПОТЕРИ ОРГАНИЧЕСКОГО ВЕЩЕСТВА И ЭЛЕМЕНТОВ ПИТАНИЯ ПРИ ВОДНОЙ ЭРОЗИИ ПОЧВ НА СКЛОНОВЫХ ЗЕМЛЯХ

The results of long-term studies of the flushing of humus and plant nutrition elements with water erosion on sod-podzolic soils are presented. Quantitative indicators of their losses with liquid and solid runoff during spring snowmelt and precipitation of runoff-forming rains under different agricultural crops have been established. During the spring snowmelt, the maximum runoff was observed on winter grain crops, the maximum soil washout was observed on winter plowing. Humus, nitrogen, phosphorus and potassium are lost mainly with solid runoff. During the spring snowmelt, the total losses of humus, nitrogen, phosphorus and potassium are 80.4, 5.4, 2.3 and 2.1 kg/ha per year, respectively, on winter crops - 28.6, 1.7, 0.7 and 0.6 kg/ha per year, under perennial grasses - 5.3, 0.2, 0.2 and 0.9 kg/ha per year. The maximum runoff and flushing of the soil during the fallout of runoff-forming rains was observed under row crops, the minimum - under perennial grasses. The main losses of humus, nitrogen and phosphorus under row and spring grain crops are noted with solid runoff. Under perennial grasses, humus is washed off more with liquid, and nitrogen and phosphorus -in equal amounts with liquid and solid runoff. Potassium is mainly carried out with the soil on row crops, and on winter cereals - with liquid runoff. On spring grain crops and perennial grasses, its losses with liquid and solid runoff are the same. In general, when cultivating row crops, humus losses with water erosion reach 240 kg/ ha per year, under spring grain and leguminous crops - 8-170, under winter grain - 25-45 kg / ha per year, and under perennial grasses no more than 10 kg/ha. Total nitrogen losses range from 12.5-46.0 kg/ha under row crops to 1.5-5.0 kg/ha under winter grain crops. Phosphorus and potassium losses amount to 4.5-20.0 kg/ha per year on row crops, 3.5-15.0 - on spring cereals and leguminous crops, 1.5-7.0 - on winter cereals and less than 2 kg/ha per year on perennial grasses.

TAX INCENTIVES TO MANAGE LAND AS A NATURAL ASSET

Topicality. Successful economic development of agriculture is one of the components of Ukraine's sustainable development. But this development very often leads to changes in natural and climatic conditions and to increased risks for doing business. Agricultural land is a natural asset and it should be taken into account that the change oflandscapes from natural vegetation to any other use can lead to loss, degradation, and fragmentation of the environment, all of which can have devastating consequences for biodiversity as a source of ecosystem services. Therefore, it is important to find ways to rationally manage the land.Aim and tasks. The purpose of our study was to substantiate the relevance of taxes for the management and rational use of land as a natural asset. As a tool, we consider a tax on crop rotation, which leads to a decrease in soil fertility and the release of carbon from dying plant residues. Crop rotation planning will help reprioritize crop selection, increase fertility and reduce carbon emissions.Research results. The main component of the sustainable development of the agricultural sector is soil fertility. At the same time, land use and agriculture are the main natural agents for reducing air pollution. Today, agriculture accounts for about 20% of greenhouse gas emissions, and humus losses range from 19% to 22% in different natural areas. Considering agricultural land as a natural asset, it should be taken into account that their irrational use leads to a change in natural and climatic conditions and an increase in risks for doing business. We have proposed to introduce carbon crop rotations as a tool for soil quality management. In our opinion, this should contribute to a change in priorities in the choice of agricultural crops, and as a result, an increase in fertility and an increase in carbon sequestration. To stimulate agricultural enterprises, we consider it expedient to introduce a tax on crop rotation. To substantiate this idea, we have created a model for the dependence of CO2 absorption/emission on the yield of various crops and a decision-making model for planning the costs of an agricultural enterprise.Conclusion. We have conducted a study of the relationship between the yield of various crops and the absorption/release of carbon dioxide. We put forward a hypothesis: there is a certain relationship between the yield of different crops and the balance of absorption/release of CO2. We have studied this connection. The model of dependence of CO2 uptake/emission on the yield of different crops shows that the ability to release carbon by plant residues of different agricultural crops has both a direct and inverse relationship with the yield of various crops. We have developed a decision-making model for planning the costs of an enterprise, subject to planning for environmental risks or paying a tax on carbon crop rotations. Thus, the problems of land use as a natural asset in agriculture can be solved by: the introduction of carbon crop rotations, which should help change priorities in the choice of agricultural crops, and the introduction of a balanced and evidence-based approach to the development and implementation of environmental taxes.