Leached Chernozem Research Articles

Application of Biotesting Methods at Assessment of Ecological State of Soils

Concentrations of heavy metals (HM) that may have a significant negative impact on plants and soil microbiota have been identified at different pollution levels for sod-podzolic, gray forest, leached chernozem and chestnut soils. The investigated soils can be arranged in descending resistance to HM in the following order: leached chernozem, gray forest soil, chestnut, sod-podzolic soil. A comparison of the results of phytotoxicity determination in growing plants on soils and on soil extracts showed that phytotoxicity on soils polluted with HM appears at lower concentrations than on soil extracts. This is a consequence of low solubility of heavy metal compounds that are strongly sorbed by the mineral and organic components of soils, and also remain in the form of poorly soluble compounds.

Effect of fertigation on yield and fruit quality of apple (Malus domesticaBorkh.) in high-density orchards on chernozems in Central Russia

The research was conducted in 2013-2015 in the experimental apple orchard of I.V. Michurin Federal Research Centre (Tambov region, Russia) with 'Zhigulevskoe' apple trees on B396 rootstock. The aim was to determine the optimal rates of nutrients by fertigation and foliar feeding efficiency. The soil was a leached meadow chernozem, low of humus, heavy loamy on sand with pseudofiber. There were recorded yield, main nutrient content in leaves and soil, as well as the humus content and soil pH, ascorbic acid, sugars and organic acids content in fruits. We applied N(10)P(10)K(10), N(20)P(15)K(20), N(25)P(20)K(25), N(25)P(20)K(30), N(30)P(25)K(30), N(35)P(25)K(35) rates (data are in kg ha(-1) of individual nutrient). Optimal fertigation rate for regions of the Central Chernozem Zone determined in our research was (in kg ha(-1)) N=25, P=20 and K=30. Excessive application of fertilizers through fertigation and also irrigation may led to soil degradation and deterioration of soil fertility, resulting in change of some physical and chemical parameters. The fertilizer rate determined during our research did not significant influence on the soil pH, humus content and cation exchange capacity. The content of ascorbic acid, sugars and titric acids of fruits at harvest was largely determined by the weather conditions of the growing year. Combination of fertigation and foliar fertilizing increased the productivity of apple trees.

Interrelations of the Bryansk paleosol (end of MIS 3) with the Holocene surface soils in micro-depressions of the central forest-steppe within the Russian Upland

A catena of the Holocene soils and interstadial Bryansk paleosol has been studied within a small closed depression in the Kazatskaya Steppe site on the Central Russian Upland. This depression is located on the territory of the Central Chernozem Biospheric Reserve, Kursk region and presumably originated from suffosion processes. Our research is aimed at understanding of interrelations between the macro- and micromorphological characteristics, certain physical and chemical properties of the Bryansk paleosols, on one hand, and those of the superimposed Holocene soil on another, taking into consideration various conditions of the present-day microrelief. The studied catena is a typical component of the landscape and soil cover structure for watersheds of the Central Russian Upland. On the micro-elevation rising 80 cm above the micro-depression bottom, the Typical Chernozems (Haplic Chernozems) are developed, on the slope – the Leached Chernozems (Luvic Chernozems), and at the bottom – the Meadow Chernozems (Stagnic Chernozems). The upper humus horizons of the Holocene soil present in all sectors of the catena. The thickness of the Ah horizon increases slightly, whereas the AB horizon decreases toward the bottom of the depression. On the slopes and at the bottom of the depression, the Ah2 sub-horizon is replaced with the AE horizon, and the Bk horizon becomes carbonates-free and turns into the Bt horizon.The change of the “normal” profile of paleosol of warm interstadial in final phase of MIS 3 started already in the last stages of its formation. The Bryansk soil is heavily deformed by cryogenic processes during the Valdai glaciation maximum (the Vladimir cryogenic horizon, MIS 2). The secondary diagenesis of the Bryansk paleosol is related to the Holocene soil-forming processes. The Holocene soils are superimposed on the Middle Valdai Bryansk paleosol, transforming it in different ways in different sectors of catena. On micro-elevation the Holocene diagenesis is minimal and consists in fragmentation by mesofauna, additional penetration of carbonates in the upper horizon of the paleosol. At the bottom of the micro-depression the Bryansk paleosol is the most transformed, and the entire profile of the Bryansk soil turned into illuvial horizon of the Holocene meadow-chernozem soil.

Assessing the Degree of Physical Degradation and Suitability of Chernozems for the Minimization of Basic Tillage

Results of studies performed in long-term stationary and short-term experiments on ordinary and leached chernozems in the Central Chernozemic Zone are presented. Agrophysical and physicomechanical parameters are proposed for assessing the degree of physical degradation of chernozemic soils. The scale of chernozem degradation has been improved. After the assessment of the agrophysical fertility parameters of old-arable soils, the limits of chernozem suitability for the minimization of basic tillage have been determined. Minimization of basic tillage is recommended for the nondegraded or slightly degraded soils resistant to compaction, with the soil bulk density of no more than 1.1–1.3 g/cm3, soil penetration resistance of 10–30 kg/cm2, and the content of coarse blocky fraction of no more than 30%.

Многолетняя динамика агрохимических свойств черноземов под яблоневыми садами

The long-term dynamics of agrochemical properties for leached chernozem under an orchard monoculture has been studied. The objects of monitoring are two testing areas in the south (“Krasnodar”) and in the center of the European part of Russia (“Michurinsk”) without applying of organo-mineral fertilizers and chemical melioration to the soil. A significant decrease of the main fertility indicators within the soils humus horizon has been revealed during the period of intensive growth and stabilization of apple trees yields for the testing area in the south of Russia: a reduction in the nitrogen mineral forms stores and nitrification ability, and in exchange potassium stores. As for the area in the center of the European part of Russia, a trend for the content of mobile forms of phos-phorus and potassium decreasing during the growth and stabilization of apple yields has been revealed. The regression models obtained as a result of the anal-ysis were linear and revealed probable significant trend of the decrease for the observed indicators over time. Quantitative changes in the parameters of the organic matter content in soils within the boundaries of the testing area made it possible to identify the processes of dehumification: in conditions of monocul-ture at the natural level of fertility. During the period from 1990 to 2014, the depletion of soil organic matter contained 7.5%. It is shown that the processes of soil organic matter depletion occur differently under different soil and climatic conditions. It is established that apple plantations, consuming the amount of available forms of mineral elements needed for the forming of sustainable yields, create prerequisites for the development of processes of chernozems chemical degradation. Absence of fertilizers and chemical reclamation on this background contribute to aggravation of this process.

Ирина Яковлевна Маслова – заслуженный агрохимик ИПА СО РАН

The article describes professional biography of a remarkable researcher Doctor of Biological Sciences Maslova Irina Yakovlevna, who as an excellent agrochemist and soil scientist had worked in the Institute of Soil Science and Agrochemistry of the Siberian Branch of the (USSR) Russian Academy of Sciences since its establishment in 1968 until recently. In 1960 Maslova I. Ya. graduated from the Moscow Timiryazev’s Agricultural Academy as a specialist in soil science and agrochemistry and for several years afterwards studied soils in the Barabinsk lowland, the Kulunda steppe and northern forest-steppe zone in the Novosibirsk region in West Siberia. In 1963 Maslova I.Ya. became a post-graduate student in the Institute of Soil Science and Agrochemistry of the Siberian Branch of the USSR Academy of Sciences and started her own research of the agrochemical properties of leached chernozems in the near-Ob River area with a special focus on soil sulfur. Notably, in 1972-1984 Maslova I.Ya. participated in the State Inter-agency research program on ultra-potassium alumosilicate ores from the Synnyr mining site in the Central Siberia, studying in detail their potential use as a chlorine-free potassium fertilizer. Since 1976 Maslova’s research had been focused mainly on soil sulfur as during her studies in agroecosystems on podzolised chernozems and grey forest soils she found that under optimum NPK supply spring wheat did not reach expected yields even under favourable weather conditions due to, as further research showed, sulfur limitation. Since then Maslova became especially interested in this nutrient, mostly In 1983-1984 Maslova I.Ya., as a member of the joint expedition team studied meadow soils in the floodplain of the Orkhon River in Mongolia, actively teaching and advising Mongol specialists in Agrochemistry and soil science. In 1992 Maslova I.Ya. successfully proved her Doctoral thesis where she substantiated that spring wheat sulfur requirements depend on the rate of nitrogen supply, as additional nitrogen input results in available sulfur deficit, at first manifested in the grain quality, and then in the total yield. Maslova I.Ya. also concluded that soils of West Siberia are very diverse in relation to sulfur content, its speciation, profile distribution and plant availability, especially in the top soil horizons where sulfur can be found mostly in non-available form. To conclude, I. Ya. Maslova’s career as a steadfast, consistent and well focused one provides a perfect pattern for contemplation by young researchers.

INFLUENCE OF BIOLOGIZATION AND CHEMICALIZATION ON WATER CONSUMPTION OF CROPS IN FODDER CROP ROTATIONS

The work presents the results of research into the effect of biologization (intercropping legume component with grain crops) and chemicalization (use of mineral fertilizers) applied in each fi eld of fodder crop rotation on the moisture content of leached chernozem in the conditions of the forest-steppe zone of Western Siberia. Water consumption and crop productivity in six-fi eld fodder crop rotations over four years of the second rotation were studied. Only recognized locally-bred crop varieties were cultivated in the experiment, such as Krasnoobsky oat, Acha barley, pea Novosibirets, vetch Priobskaya 25, alfalfa Flora, awnless brome Rassvet, hybrid maize Obsky 140 SV and fodder bean Sibirskiye. It was established that intercropping of the legume component caused the increase in the consumption of productive moisture reserves from the soil by fodder agrocenoses from 66 mm to 84 mm and the application of mineral fertilizers resulted in the moisture consumption increase of up to 74 mm. The use of methods for fodder crop rotation improvement led to the increase in the total water consumption of fodder crops. As a result of mineral fertilizer input it increased from 244 mm to 252 mm, and due to the intercropping of legume component it rose up to 262 mm. With regard to increasing the consumption of productive moisture reserves from the soil layer of 0-100 cm, crops ranked in the following order: perennial grasses – silos – fodder-grain crops – cover crops, whereas with regard to increasing the total water consumption they ranked in reverse order. The use of chemical agents increased the yield of dry matter by 1.6 times, while water consumption coeffi cient decreased by an average of 2.2 times in the crop rotation. Application of biologization led to the yield increase by 1.4 times, reducing water consumption coeffi cient by 1.9 times. In the control crop rotation, maize consumed the least amount of moisture (346 m 3 /ton of dry weight), and the most moisture was consumed by the grain part of barley (2933 m 3 /t of dry weight). When applying mineral fertilizers, the maximum and minimum water consumption fell on the same crops – 290 m 3 /t and 1087 m 3 /t dry weight respectively. When the legume component was sowed in each crop rotation fi eld, the minimum moisture consumption was in the fi elds with awnless brome intercropped with alfalfa, namely 384 m 3 /t dry weight, while the maximum consumption was in the fi elds with barley and pea grains – 1199 m 3 /t dry weight.

Поживний режим чорнозему вилугуваного за різних систем удобрення буряків цукрових

The purpose. To study efficiency of traditional and alternative organic-and-mineral fertilizer systems in formation of nutritive regimen of sandy loam leached chernozem. Methods. Short-term field, laboratoryanalytical, mathematical processing of the gained results. Results. Dynamics of the content in soil of movable joints of nitrogen, phosphorus and potassium is shown at application for cultivation of sugar beet of traditional and alternative fertilizer systems. Conclusions. The alternative fertilizer system (N90P60K90 + straw + green manure crop) is recognized to be more efficient for improvement of nutritive regimen of leached chernozem. On the beginning of vegetation the content of mineral nitrogen at its application has increased up to 30–35 kg/hectare with flushing out of nitrate nitrogen to the depth of 0–90 cm, and of ammonium nitrogen — to 0–60 cm. During the vegetation period nitrate nitrogen of soil was used by plants on 70–90%, and ammonium nitrogen — on 10–40%. The content of movable joints of phosphorus and potassium at alternative fertilizer system increased mainly in arable layer of soil (0–30 cm) on 20 and 10 mg/kg of soil accordingly (60 and 30 kg/hectare) and preserved relative stability during vegetation.

Интенсивная биологизация земледелия и её результаты (на примере ООО "Агрофирма "Слава картофелю" Чувашской Республики)

The experience of the agriculture biologization is assessed on the example of the “Slava kartofelju” Agrofirm situated in the Komsomolsky District of the Chuvash Republic. The soil is presented by medium loamy leached chernozems. The content of humus in the arable layer varies from 7 to 11%, and the depth of the fertile layer varies from 50 to 110 cm. Soil-forming rocks are loess, loess-like loam (varying from light loam to heavy loam). In each crop rotation, perennial fabaceous or fabaceous-cereal crops were necessarily present. Straw and fertilizer were implemented to the soil in order to improve the balance of humus and biological parameters. Within the area of pea and cereals cultivation, due to the straw incorporation into the soil 36.6 kg of nitrogen, 16 kg of phosphorus and about 66 kg of potassium were returned to the soil per hectare on average. The share of melilot in the structure of crop areage contained 21.3%. In 2016 the amount of nitrogen, phosphorus and potassium which entered the soil with melilot green manure mass contained: for nitrogen - 1055 t of ammonia nitrate, for phosphorus - 194 t of ordinary superphospate, for potassium - 470 t of potassium chloride. For the repeated green manuring after the melilot incorporation into the soil in 2016, the oil radish was sown in the beginning of the third decade of June on the area of 429.6 ha. The positive balance in potassium and phosphorus content was achieved due to the use of straw and broad implementation of green manure. Therefore, the share of biological nitrogen in the balance contained 76.3%, mineral nitrogen 23.7% correspondingly, and as for phosphorus and potassium it contained 42.6 and 68.0%

Experimental Study of Factors Affecting Soil Erodibility

The effect of different factors and preparation conditions of monofraction samples from the arable horizon of leached chernozem on soil erodibility and its relationship with soil tensile strength (STS) has been studied. The exposure of samples at 38°C reduces their erodibility by two orders of magnitude. The drying of samples, on the contrary, increases their erodibility. It has been shown that erodibility decreases during the experiment. It has been found that the inoculation of soil with yeast cultures (Naganishia albida, Lipomyces tetrasporus) reliably increases the STS value in 1.5–1.9 times. The sterile soil is eroded more intensively than the unsterile soil: at 4.9 and 0.3 g/(m2 s), respectively. The drying of soil followed by wetting to the initial water content (30%) has no significant effect on the STS value in almost all experimental treatments.

The contents and forms of cadmium compounds in leached chernozem of the Western Caucasia in terms of agricultural soil genesis

The contents and forms of cadmium compounds in leached chernozem of the Western Caucasia in terms of agricultural soil genesis

ЭФФЕКТИВНОСТЬ ОБРАБОТКИ ЧЕРНОЗЕМА ВЫЩЕЛОЧЕННОГО НА АГРОФИЗИЧЕСКИЕ ПОКАЗАТЕЛИ И УРОЖАЙНОСТЬ ЗЕРНА КУКУРУЗЫ В ЦЕНТРАЛЬНОЙ ЗОНЕ КРАСНОДАРСКОГО КРАЯ

ЭФФЕКТИВНОСТЬ ОБРАБОТКИ ЧЕРНОЗЕМА ВЫЩЕЛОЧЕННОГО НА АГРОФИЗИЧЕСКИЕ ПОКАЗАТЕЛИ И УРОЖАЙНОСТЬ ЗЕРНА КУКУРУЗЫ В ЦЕНТРАЛЬНОЙ ЗОНЕ КРАСНОДАРСКОГО КРАЯ

ВКЛАД БИОЛОГИЧЕСКОГО АЗОТА ЛЮЦЕРНЫ В АЗОТНЫЙ ФОНД ЧЕРНОЗЕМА ВЫЩЕЛОЧЕННОГО ЗАПАДНОГО ПРЕДКАВКАЗЬЯ

ВКЛАД БИОЛОГИЧЕСКОГО АЗОТА ЛЮЦЕРНЫ В АЗОТНЫЙ ФОНД ЧЕРНОЗЕМА ВЫЩЕЛОЧЕННОГО ЗАПАДНОГО ПРЕДКАВКАЗЬЯ

Влияние приемов основной и предпосевной обработки почвы и удобрений на продуктивность звена полевого севооборота

The article provides the results of 2014-2016 studies of the effect of macro- and micro fertilizers in the link of field crop rotation on fodder productivity and weed infestation on the background of basic and presowing cultivation of leached chernozem. The link of the crop rotation is presented by: (barley + meadow clover - meadow clover of 1 year of use -meadow clover of 2 year of use). In the main soil treatment variants, plowing (with PLN-4-3.5), disking (with PM-3 x 4) and non-moldboard tilling (with KPE-3.8) were used. The presowing treatment was carried out by the units IMT-616 (Europack) and KPS-4. Microfertilizers are represented by a complex of chelated microelements Microvit. The first grain crop of the rotation link (barley) provided the largest yield of feed units per 1 hectare - 3.72 tons of feed units/ha on plowing, the smallest on non-moldboard tillage (2.82 tons of feed units / ha), which was 0.24 tons of feed units/ha more than on the background of disking (3.06 tons of feed units / ha). Foliar top dressing with Microvit was more effective than seed treatment on all backgrounds of basic tillage, where the increase in productivity was from 0.25 to 0.66 tons of feed units / ha, while in seed treatment the increments were from 0.15 to 0.38 tons of feed units / ha. Feeding efficiency of the clover of 1 year of use in the sum for two cuts varied from 4.16 to 5.30 tons of feed units/ha. According to the basic methods of soil cultivation, this indicator varied; between plowing (4.98 tons of feed units/ha) and disking by 0.50 tons of feed units/ha, between plowing and non-moldboard tillage by 0.36 tons of feed units/ha in favor of plowing. In the second year of use, the growth of crop productivity was also observed from plowing (3.52 tons of feed units/ha) to disking (2.62 tons of feed units/ha) with an intermediate value on the background of non-moldboard tillage (3.12 tons of feed units/ha). Over the years of research, the application of the Microvit preparation on clover for all variants of basic tillage was most effective in foliar top dressing, where an increase in productivity was observed from 0.20 to 0.67 tons of feed units/ha versus 0.06-0.46 tons of feed units /ha at crop seeds treatment. The use of clover for two years for food and subsequent plowing up as siderate helps to reduce the contamination of the crops in the field crop rotation link from 17% in 1 year of use to 7% in 2 year of use in comparison with weed infestation of cover crop.

Weed infestation of winter wheat in various crop rotations

Purpose. To investigate weed distribution in winter wheat sowings as affected by crop rotation and fertilizer backgrounds.Methods. Quantitative and gravimetric.Results. Presented in the article are the experiment results on the quantitative composition of weeds and the dynamics of their accumulation in winter wheat sowings as affected by crop rotation and fertilization program. The stationary experiment was carried out on the typical leached chernozem in the zone of unstable wetting under the conditions of the Bila Tserkva Research & Breeding Station. The greatest number of weeds per 1 m2 in the period of spring tillering was observed on the unfertilized background in crop rotation (145.3) and grain – row crop rotation (146.3), that equals to 13.46 and 16.4 dt/ha, respectively. Application of fertilizers reduced the mass of both monocotyledonous and dicotyledonous weeds. Against the fertilized background, the number of weeds reduced to 27.1 and 34.0, that was in terms of weight to 6.20 and 5.77 dt/ha, respectively.Conclusions. The largest mass of weeds in winter wheat sowings was observed in unfertilized treatments. Application of fertilizers in winter wheat sowings during the spring tillering reduces the number of weeds per 1 m2 against the background of fertilizers in grain – row crop rotation to 34.0–41.0, including cereal weeds 25.6–13.0, dicotyledons 73.5–86.0 and perennial weeds 0.9–0.8. The weight of weeds against the fertilized background at the wheat harvesting amounted to 6.20 dt/ha in crop rotation and to 5.77 dt/ha in grain – row crop rotation, with the weight of cereal weeds of 1.24 and 1.10 dt/ha, respectively. The number of perennial weeds in grain – row crop rotation did not exceed 0.34 and 0.67 dt/ha and in crop rotation 0.21 dt/ha. Among the dicotyledonous weeds, the most abundant in terms of weight per 1 hectare was Amaranthus retroflehus L. with the weight ranged from 3.2 to 1.5 dt/ha. The increase in the weight of the weeds in crop rotation was due to an increase in the number of Amaranthus retroflehus L. (3.2 dt/ha) and Spergula arvensis L. (0.84 dt/ha).

Energy efficiency of a link of various crop rotations

Purpose. To substantiate the energy efficiency of various crop rotations as affected by a system of fertilization, energy removal with harvest and energy costs.Methods. The measure of energy efficiency of crop cultivation technology is the energy efficiency ratio, which expresses the ratio of the total energy content of the cultivated crop to the amount of non-renewable energy spent on its cultivation.Results. The research was carried out in the stationary experiment on typical leached chernozem in the zone of unstable wetting in six-course multivariate crop rotation: crop rotation (33% fodder crops, 17% row crops, 50% grain crops), row crop rotation (17% fodder crops, 50% row crops, 33% grain crops) and grain-row crop rotation (17% fodder crops, 33% row crops, 50% grain crops). The experiment has shown that against the background of 16.6 t/ha of manure + N53.3P53.3K53.3, the energy removal with the harvest in the link of crop rotation amounted to 319169 MJ, in the link of row crop rotation 292569, and in the link of grain-row crop rotation 301963 MJ, which was by 48, 44 and 48%, respectively, higher than the energy removal against the background without fertilization. The energy efficiency ratio (kee) had the highest value in grain-row crop rotation (4.39), while in the crop rotation and grain-row crop rotation 4.03 and 3.97, respectively. In fertilized crop rotation, the yield of energy from the crop was at the level of the organic-mineral fertilizer system in treatments of ploughing-in crop residues against the background of mineral fertilization. High fertilizer rates applied in grain-crop rotation increase the yield of energy removal with the crop. The reduction of fertilizer rates significantly reduces both the energy removal and the efficiency of energy.Conclusions. The highest yield of energy with the crop (319169 MJ) was recorded in crop rotation in the link of oat – winter wheat – sugar beet at the background of application of 16.6 t/ha of manure + N53.3P53.3K53.3. Ploughing- in crops residues against the background of the mineral system provides a yield of energy with a yield of 303534 MJ at kee 4.06, which is at the level organic-mineral fertilizer system. High fertilizer rates applied in grain-seed crop rotation increase the yield of energy with the yield, but kee does not exceed 4.31–4.33. The reduction of fertilizer rates significantly reduces both the energy removal by crop and the energy efficiency ratio.

Особенности латерального и радиального распределения металлов в почвах агроландшафтов Самарской области

Одним из факторов, изменяющим структуру и функции почв агроландшафтов, являются соединения металлов. В работе выявлены и оценены особенности латерального и радиального накопления тяжелых металлов (Pb, Cd, Zn, Cu, Mn, Cr, Fe) в темно-каштановых, темно-серых лесных типах почвах, а также во всех основных подтипах черноземов (южном, обыкновенном, типичном, выщелоченном, оподзоленном) в условиях Самарской области. Почвенные образцы анализировали методом атомно-абсорбционной спектрометрии с пламенной и беспламенной атомизацией. Установлено, что содержание Pb, Cd, Zn, Cu, Mn, Cr, Fe в гумусовых горизонтах темно-каштановых, темно-серых лесных почв и в подтипах черноземов не выходит за пределы ПДК. Превышение над кларками земной коры выявлено для Pb в темно-серых лесных и темно-каштановых почвах, для Cd — в черноземах типичных и выщелоченных, для Mn и Pb — в темно-серых лесных почвах, черноземе южном, для Zn — в темно-серых лесных почвах. Коэффициенты накопления, показывающие превышение над фоновым значением, в почвах агроландшафтов представлены следующим убывающим рядом: Fe(1,9) > Zn(1,7) > Cu(1,5) > Mn(1,4) > Cr(1,4) > Pb(0,9) > Cd(0,2). По суммарному показателю загрязнения исследованные почвы образуют ряд (в порядке снижения концентрации): темно-серые лесные (16,15) > чернозем южный (9,81) > чернозем выщелоченный (8,72) > чернозем обыкновенный (8,64) > чернозем типичный (8,12) > темно-каштановые (7,83) > чернозем оподзоленный (4,79). Распределение металлов в почвенных горизонтах равномерно-аккумулятивное. Элементами выноса во всех изученных почвах являются Cr(0,42), Fe(0,43), Cu(0,66); Cd активно накапливается в выщелоченных (3,55) и типичных (2,17) черноземах, Mn — в темно-серых лесных почвах (2,04); Pb равномерно распределен в профиле почв и аккумулируется в профиле серых лесных (1,24) и темно-каштановых (0,94) почв; Cd, Zn, Cu, Cr накапливаются в верхнем пахотном горизонте; Fe и Mn мигрируют в нижележащие слои почвы.

FEATURES OF HUMUS AND NITROGEN ECOLOGICAL STATUS FOR STEPPE ZONE CHERNOZEMS OF THE NORTH CAUCASUS

The purpose of the paper presented is to determine tendency and intensity for quantitative and qualitative changes in humus and nitrogen status of chernozems. The system approach to study natural objects is assumed as the basis for research methodology of humus and nitrogen status of soils. It is established that the depth typical values of chernozem humus horizons in the North Caucasus are 120-180 cm for South European facies of leached chernozems, 100-170 cm for modal chernozems, 70-160 cm for common chernozems, 70-120 cm for southern chernozems; for East European facies of southern chernozems the value is 55-70 cm. A distinctive ecological feature of the soils is thought to be a low humus content in the arable layer, its deep distribution along the profile and slight variability among each subtype. Nitrogen quantity in chernozems of the region variates within a comparatively wide range: 0.20-0.35 % in South European facies of leached, modal and common chernozems, 0.22-0.30 % in East European facies of southern chernozems. Southern chernozems of South European facies contain least of all nitrogen, i.e., 0.18-0.22 %. Total nitrogen composition is mainly presented by non-hydrolysable facies, making 74.2-78.9 %. The research materials are intended to design farming systems on the landscape basis for specialists dealing with the issues of soil preservation, increasing soil fertility as well as environment protection. The results of the research may contribute to making a purposeful impact on decision making to control humus and nitrogen status of soils, thus serving as the basis for preservation of bioecological potential of chernozems.

PECULIARITIES OF HUMUS AND NITROGEN ECOLOGICAL STATE FOR STEPPE ZONE CHERNOZEMS OF THE NORTH CAUCASUS

Purpose of the paper presented is to determine tendency and intensity for quantitative and qualitative changes in humus and nitrogen of chernozems. System approach to study natural objects is assumed as the basis for research methodology of humus and nitrogen state of soils. It is established that the depth typical values of chernozem humus horizons in the North Caucasus are 120–180 cm for South European facies of leached chernozem, 100–170 cm for modal chernozems, 70–160 cm for common chernozems, 70–120 cm for sothern chernozems; for East European facies of southern chernozems it is 55–70 cm. A distinctive ecological feature of soils is a low humus content in an arable layer, its deep distribution along the profile and. slight variability among each subtype. Nitrogen quantity in chernozems of the region variates in comparatively wide ranges: in South European facies of leached, modal and common chernozems 0,20–0,35%, in East european facies of southern chernozems 0,22–0,30%. Southern chernozems of South European facies contain least of all nitrogen 0,18–0,22%. Tota1 nitrogen composition is presented in the main with nonhydrolysed facies – 74,2–78,9%. The research materials are intended to design farming systems on the landscape basis for specialists who are busy with the problem of conservation and increase in soil fertility and environment protection. The results of research allow to realize purposeful impact on decision making to control humus and nitrogen state of soils and this will serve as the basis for conservation of bioecological potential of chernozems.

ПУТИ РЕГУЛИРОВАНИЯ ПОЧВЕННОГО ПОГЛОЩАЮЩЕГО КОМПЛЕКСА ЧЕРНОЗЕМА ВЫЩЕЛОЧЕННОГО АЗОВО-КУБАНСКОЙ РАВНИНЫ

ПУТИ РЕГУЛИРОВАНИЯ ПОЧВЕННОГО ПОГЛОЩАЮЩЕГО КОМПЛЕКСА ЧЕРНОЗЕМА ВЫЩЕЛОЧЕННОГО АЗОВО-КУБАНСКОЙ РАВНИНЫ