Soil Humus Research Articles

Deinococcus detaillensis sp. nov., isolated from humus soil in Antarctica.

A Gram-staining-positive, non-motile, coccus or short-rod-shaped bacterium, designated H1T, was isolated from a humus soil sample in the Detaille Island of Antarctica. The 16S rRNA gene sequence result indicated that strain H1T shared the highest 16S rRNA gene sequence identity with the type strain of Deinococcus alpinitundrae (96.2%). Growth of strain H1T occurred at 4-25°C, pH 6.0-8.0 and in the presence of 0-1.0% NaCl (w/v). The respiratory quinone was MK-8. The major fatty acids were C16:0, C17:0 cyclo and summed feature 3 (C16:1 ω7c/C16:1 ω6c). The polar lipids were aminoglycophospholipid, aminophospholipid, glycolipid and glycophospholipid. The cell wall peptidoglycan type was A3β. The genomic DNA G + C content was 61.3mol%. The average nucleotide identity (ANI) between strain H1T and the closely related Deinococcus members was below the cut-off level (95-96%) for species identification. Based on the above results, strain H1T represents a novel species of the genus Deinococcus, for which the name Deinococcus detaillensis sp. nov. is proposed. Type strain is H1T (= CGMCC 1.13938T = JCM 33291T).

Feasibility analysis of waste humus soil for Urban Greening

From the landfill site which was closed for 15 years,10mm sieved humus soil was extracted as test material, to build the wild plant simulation leaching system. The regularity of pollutant release and the migration of heavy metals were studied in the system, in order to explore the feasibility of using humus soil for urban greening. The test results showed that the pH value of the leaching solution is between 6.8 and 7.7; the COD value is basically stable between 40 mg / L and 75 mg / L; the concentration of NH3-N is less than 1 mg / L; Between 200mg / L, it mainly exists in the form of nitrate nitrogen. Total and Morphology Analysis of four heavy metals (Cu, Zn, Pb, Ni) showed that all the metals were able to achieve the soil environmental quality risk of soil pollution control standard for GB36600-2018 in the nature of the land of green space and square, and the proportion of exchangeable and carbonate binding states in the four heavy metal were small, meanwhile the dissolution and mobility were small. In conclusion, humus soil has the feasibility to use for urban greening.

Influence of organic technology on vegetative growth and production of three climbing edible roses (Rosa sp.)

In the present study, three climbing edible roses (‘Crown Princess Margareta’, ‘Falstaff’ and ‘Brother Cadfael’) were evaluated for total vegetative growth and flowers production, besides correlations with soil microbiological and agrochemical parameters. The applied organic technology included a soil preparatory stage with three ameliorative plants (Sinapis alba L., Phacelia tanacetifolia L. and Tagetes patula L.) and two organic mulch variants (wood chips and wool) after plantation. In variant Sinapis and Tagetes, all three varieties of roses showed the highest values for parameters: total vegetative growth, number of shoots, average shoots length and flowers number. Significant positive correlations between biometric parameters and soil bacteria, phosphorus, mineral nitrogen, potassium (0-20 cm horizon) and humus (20-40 cm horizon) content were observed. Significant positive correlations between the number of flowers and the soil respiration coefficient, soil content in phosphorus, potassium, humus, total soluble salts and mineral nitrogen were noticed. Negative correlations with soil pH have been observed. Taking into account the data obtained in the two flowering stages in 2017, the average yield per hectare cultivated with ‘Crown Princess Margareta’ was 9.44 t petals/ha. For the ‘Falstaff’ and ‘Brother Cadafael’ cultivars, the yields were 7.54 and 5.62 t petals per hectare respectively.

Diversity and Distribution of Wild Fleshy Fungi in District Jammu, J&K, India

Fungi, the most diverse group of organisms, are very important for the nutrient cycling of an ecosystem. Fleshy fungi are described as non- photosynthetic hyphal eukaryotes which form macroscopic fruiting bodies. They are mostly saprophytic, inhabiting different substratum and occurring in different seasons. The present study was conducted in five locations of district Jammu to study the diversity, distribution and seasonal availability of fleshy fungi. The results shows that a total of 45 taxa belonging to 27 genera spread over 17 families and 7 orders were found in the study area. Agaricaceae was the most dominant family represented by 18 species. Bajalta had the maximum diversity with highest number of species (15), Menhinick's richness (3.87), Margalef's richness (5.17) and Shannon's diversity (2.71). Humicolous i.e. species preference humic soil was the most common (55.6%) habitat for the macrofungus. The Principal Component Analysis also confirmed that humicoulous fleshy fungi are the driving habitat of the study area and the two agricultural sites Arnia and R.S. Pura are having close affinity. The availability of the fleshy fungi in the five sites varied significantly (ANOVA; F = 13.32 and P < 0.001) and rainy season (July to September months) was the most preferred season.

Total organic carbon and the humic fractions of the soil organic matter in silvopastoral system

In agricultural production systems soil organic matter (SOM) is of paramount importance when assessing soil quality. Therefore, the objective of this study was to quantify the total organic carbon (TOC) and the humic fractions of the soil organic matter in silvopastoral system (SS) and to compare them with the conventional pasture system (CP) and a native vegetation area of Cerrado (NV). In the SS, soil samples were collected at distances 2.5, 5.0, 7.5 and 10 m from the eucalyptus row. Soil samples in each system were collected in the 0-10, 10-20 and 20-30 cm layers. The following parameters were determined: TOC, organic carbon associated with minerals (OCam), particulate organic carbon (OCp) and carbon of the humic soil substances. Carbon management index (CMI) and the sum of humic substances (SHs) were also calculated. SS was able to promote larger increases in the TOC, OCam and carbon stocks in the humic fractions when compared to CP and was also able to increase OCp and CMI values in depth. Soil sampling distances in the silvopastoral system had no significant influence on the changes in total carbon stocks and short-term SOM fractions. Furthermore, the land use with two years of SS implementation is not yet able to provide for most of the evaluated attributes with values equal to or higher than the soil with NV.

Effects of exogenous selenium levels on humus characteristics in selenium-enriched soil and lead accumulation in Brassica juncea

Many selenium (Se)-enriched soils suffer from severe lead (Pb) contamination. Many studies indicated that soil humus can effectively absorb heavy metal ions, and Se can alleviate Pb accumulation in plants. However, few studies explored the effects of exogenous Se levels on humus composition in Se-enriched soil and Pb enrichment in Brassica juncea (B. juncea). We conducted a pot experiment. First, the Se-enriched soil sample was mixed with 200 mg·kg−1 level of Pb and maintained in a stable equilibrium for 2 months. Second, the soil was treated in different ways. Six treatments were performed as follows: one control treatment (CK) was included, and five different doses of Na2SeO3 (S1, S2, S3, S4, and S5) were applied to the pots. Each treatment was prepared in triplicate. Then, the B. juncea seeds were sown in each pot. Finally, on the 40th day, B. juncea plants in each pot were harvested and soil was sampled for subsequent experimental analysis. The different levels of selenite decreased the Pb content in roots, stems, and leaves of B. juncea by 5.43–48.70%, 5.13–39.86%, and 6.62–31.91%, respectively, and significantly increased the Se contents by 7.22–24.21, 5.91–34.11, and 12.49–57.06 folds compared with control treatment, respectively. The total Pb in the soil was reduced by 1.06–13.68% and soil pH was increased by approximately 0.06–0.21 units in all treatments. Exogenous Se also reduced diethylenetriaminepentaacetic acid (DTPA)-extracted Pb and exchangeable and iron-manganese oxide-bound Pb but increased the content of carbonate-bound and residual Pb. The composition of humus followed this order as follows: humic acids (HA) < fulvic acids (FA) << humin (HM); the adsorption isotherms of HA and FA for Pb2+ were well described by the Langmuir adsorption model, and the adsorption process were positively correlated with the Pb2+ concentration (P < 0.05). The Se levels, contents of humus components, and Pb concentration in soil were negatively correlated with each other. The addition of low Se levels can effectively antagonize Pb in Se-enriched soil and contribute to the adsorption of Pb by soil humus components, inhibiting the migration of Pb in soil-B. juncea systems to reduce the Pb accumulation in B. juncea.

Effect of ravined forest biogeocenoses on soil humus status in a steppe environment

A detailed study of the relationships between all components of each biogeocenosis is needed for its in-depth investigation. According to the concept of biogeocenoses developed by V. M. Sukachev, soil is one of the five components of biogeocenosis being its resulting unit. Soil is a bioinert component body of biogeocenosis. Playing the role of a subsystem, it is characterized by self-regulation, stability, direct and feedback mechanisms, self-restoring fertility, a specific biological cycle of substances and energy flow against the background of a specific natural geographical area. When the soil testing, its chemical, physical, water, micromorphological properties should be determined, and, above all, a total humus content and quality. Humus affects all important soil properties. In fertility, its essential role consists in a nutrient source as a factor that has a physiological effect on plants. A role of humus in improving the physical, thermal and water properties of soils is well-known. The total content and group composition of humus are also determined during the diagnosis and classification of soils. For a more detailed description of humus, Grishina and Orlov proposed a system of indicators of soils humus condition. This is a level of humus content and reserves, its profile distribution, type of humus, degree of humification, etc. In this work, we made an attempt to diagnose the soils of ravined biogeocenoses and steppe virgin lands in Dnipropetrovsk region on the basis of a number of the above parameters. To compare, the common steppe virgin chernozem and forest chernozems of the northern and southern variants of the ravines were used. The study was carried out in the fresh linden-ash oakery (the Kapitanovsky Bayrak) and in the fresh maple oakery (the Viyskovoy Bayrak) occured in the middle part of the slopes of the northern exposition. The paper presents data on the study of the ravined forest biogeocenoses influence on the total content and qualitative composition of soil humus in the northern and southern variants of Dnipropetrovsk region in comparison with the steppe virgin soil. It was established that the total humus content and reserves in the layer of 0–20 cm increased and varied from moderate to high under the influence of ravined forest vegetation; the type of humus turns from humate to fulvate-humate, which has a positive effect on plant growth and development, as it makes nutrients more mobile and available to plants. Under the influence of forest vegetation in the ravines, the soil humus condition improved, namely, the total humus content and reserves in the 20 cm layer varied from moderate to high, and the type of humus turned from humate to fulvate-humate. Our data confirmed O. L. Belgard and A. P. Travleev provisions that forests in the steppe zone effect positively on soil properties, in particular their humus condition, in contrast to the forest zone.

The role of an urban park's tree stand in shaping the enzymatic activity, glomalin content and physicochemical properties of soil

Soil enzymes play a key role in the circulation of nutrients and the functioning of the ecosystem. The aim of the study was to assess how the tree species of urban agglomerations affect soil quality and enzymatic activity (dehydrogenases DEH, catalase CAT, alkaline AlP and acid AcP phosphatase, protease PR, β-glucosidase GLU, and urease UR). To this end, soil samples were taken from beneath nine park trees. The risk of soil contamination by selected heavy metals (Pb, Ni, Cd) was also investigated against the background of the selected physicochemical properties. Enzyme activity results were used to calculate multi-parametric indices of soil quality: availability factor (AF), enzymatic pH indicator (AlP/AcP), biological index of fertility (BIF), geometric mean (GMea), alternation index (Al3), biochemical soil activity (BA16 and BA17). The results showed statistically significant differences in physicochemical and enzymatic properties of soil depending on tree species. Correlation analysis showed that the content of total organic carbon (TOC), total nirogen (TN), total phosphorus (TP) and humus (OM) in soil significantly influenced the activity of the studied enzymes and glomalin content. AF coefficient values (1.84%–18.19%) suggest that the bioavailability of available phosphorus (AP) was sufficient. The Pb, Ni, Cd content results were found to be low and did not exceed the permissible concentrations. DEH, CAT and AlP activity were highest under common hawthorn, and AcP, GLU and PR under northern white cedar. The calculated enzymatic indicators proved to be a sensitive and accurate indicator of the dynamics of changes taking place in the city park soil. Based on the results, an attempt can be made to assess the planning of sustainable development of studied areas of urban parks.

A Rapid Experimental Procedure to Assess Environmental Compatibility of Conditioning Mixtures Used in TBM-EPB Technology

Earth Pressure Balance (EPB) Tunnel Boring Machines (TBM) are currently the most widely used machines to perform tunnel excavation, particularly in urban areas. This technology involves the injection of chemicals as conditioning mixtures, which commonly raises concerns limiting the reuse of soils after excavation. This study deals with the prospect of a simplified, rapid and replicable methodology for the evaluation of the biodegradability of these conditioning mixtures. For this purpose, the biodegradation of three commercial conditioning mixtures was investigated in closed bottle tests by investigating the effect of different mixtures dosages and two different inocula (soil humus and Bacillus Clausii). While using soil humus as inoculum, a comparative study of biodegradation of the three investigated mixtures was successfully carried out; in the case of Bacillus Clausii, it was not possible to make a comparison between the different formulations in a short time. The adoption of soil humus satisfied only the criteria of rapid test, while the Bacillus Clausii, as specific inoculum, can meet the criteria of replicable results. For this reason, in the second part of this experimental study, a rapid and replicable procedure was proposed and validated. A kinetic study of organic carbon removal was also carried out.

Precocious 19th century soil carbon science

Soil organic matter is important for nutrient exchange in the soil environment, carbon sink, and soil fertility. Soil scientists usually estimate the amount of organic matter in a soil from its carbon content using the 1.724 conversion factor. The origin of this conversion factor is conventionally attributed to Jacob Maarten Van Bemmelen, a Dutch chemist. In the early nineteenth century, science academies devoted considerable attention to understanding soil humus to increase agricultural productivity. Van Bemmelen investigated the fertility of soils for growing tobacco in Indonesia. Van Bemmelen's 1890 publication used the 1.724 factor for estimating humus content from elemental analysis of C concentration. A survey of the scientific literature from the same period indicated that Emil Wolff was the first to suggest the factor. This paper draws a brief historical summary of van Bemmelen's research on soil organic matter, and discusses the origin and use of the 1.724 factor using the scientific literature from 1900s to 1930s. The origin of the factor is contextualized with the emerging humus theory of the 19th century. Our study suggests that the factor has been erroneously attributed to van Bemmelen and widely used in English, French, Dutch, and German literature. The 1.724 factor was originally developed for the conversion of carbon to humic substances, which themselves do not have a clear definition. Many regional studies have indicated the inadequacy of the factor.

Multitechnique dating of earthen irrigation canals at the La Playa site, Sonora, Mexico

AbstractLa Playa (SON:F:10:3) is an archaeological site in Sonora, Mexico that contains the remains of an extensive preceramic earthen irrigation canal system. Modern floodplain erosion has destroyed the majority of these canals, but geoarchaeological investigations on areas of the system that remain reveal much about this early agricultural technology. Comprehensive dating using accelerator mass spectrometry 14C on gastropods, charcoal, and soil humates and single‐grain optically stimulated luminescence (OSL) dating on canal sediments revealed that multiple irrigation systems were used at La Playa during at least two periods during the Early Agricultural period (~750–350 B.C. and ~ A.D. 50–250). 14C and OSL age estimates from canals are in agreement with the earliest direct dates on maize from La Playa (A.D. 20–240), indicating that the introduction of maize corresponds to a significant investment in the modification of the floodplain environment for canal irrigation. The late phase of canal use (~A.D. 50–250) occurs before destructive floodplain erosion at the site. This is contemporaneous with local cultural changes, including the development of a new ceramic tradition, changes in burial practices, and changing subsistence strategies. These results demonstrate the utility of the combined 14C and OSL approach for dating ancient earthen canals.

Схожість, збережуваність і стан сіянців сосни звичайної (Pinus sylvestris L.), вирощених у контейнерах

На базі двох підприємств Харківського обласного управління лісового та мисливського господарства Державного агентства лісових ресурсів України, а саме ДП "Чугуєво-Бабчанське ЛГ" та "Вовчанське ЛГ" в умовах Лівобережного Лісостепу України визначено ґрунтову схожість сіянців сосни звичайної у контейнерах із різним складом субстрату. Досліджено та узагальнено значення збереженості та життєвого стану сіянців з урахуванням впливу складу субстрату коренезакриваючої грудки контейнера. Дослідним шляхом проаналізовано вісім варіантів субстратів: чотири двокомпонентних торфовмісних та чотири трикомпонентних тирсо-перегноєвмісних. Встановлено комплексну перевагу над контролем за названими вище біометричними показниками варіантів із використанням торфу з базовим ґрунтом в субстраті Тф : Ґ – 1 : 1 та найбільшою мірою варіанта з використанням ґрунту, перегною й тирси у пропорціях частин 6 : 3 : 1. Результати досліджень із визначення оптимального складу субстрату для вирощування сіянців сосни звичайної із закритою кореневою системою підтвердили високі показники схожості, отримані у варіантах з використанням трикомпонентних сумішей перегною, тирси та темно-сірого опідзоленого середньо суглинкового лісового ґрунту на лесах. Серед випробуваних субстратів при об'ємі контейнера 500 см3 за комплексом переваг за досліджуваними показниками схожості, збережуваності та стану торфовмісний варіант із рівними частинами темно-сірого лісового середньо суглинкового опідзоленого ґрунту та торфу (Тф : Ґ – 1 : 1) та варіант трикомпонентної суміші Ґ : П : Т – 6 : 3 : 1 є найбільш збалансованими за основними ґрунтовими параметрами та найбільш оптимальними з досліджуваних для продуктивного росту сіянців сосни звичайної із закритою кореневою системою. Темно-сірі лісові опідзолені середньо суглинкові ґрунти на лесах за рівнем потенційної родючості є одними з найродючіших ґрунтів України. Їх формування відбувалося під достатньо розрідженими широколистяними лісами з добре розвиненим трав'яним покривом на важко глинистих карбонатних лесах. Поєднання таких факторів ґрунтоутворення, як наявність значної кількості високо зольного органічного опаду, а також материнської породи, насиченої кальцієм та глинистими частками, надає темно-сірим опідзоленим ґрунтам високої поживної здатності.

Effect of lignosulfonate on the adsorption performance of hematite for Cd(II)

Lignin is a precursor of humus in soil and sediment. Lignin can be separated from vascular plants in the form of lignosulfonate via pulping processes. On the other hand, composites of iron oxide and organic matter can adsorb heavy metals, and thus influence the migration of these heavy metals in the environment. In this paper, a hematite/lignosulfonate composite (HLS) was prepared via coprecipitation to compare the adsorption performance of hematite (α-Fe2O3) toward Cd(II) before and after the incorporation of lignosulfonate (LS). The HLS is found to exhibit a weakly crystalline structure and possess a large number of nanoscale particles. Specific surface area of HLS (291.97 m2/g) is about 11 times that of α-Fe2O3, and the pore volume of HLS (0.22 cm3/g) is twice that of α-Fe2O3. The adsorption of Cd(II) is well illustrated by the pseudo-second-order adsorption kinetics and the initial adsorption rate (h) of HLS is 13.83 times that of α-Fe2O3. The maximum adsorption capacities are significantly improved from 4.89–6.35 mg/g (α-Fe2O3) to 39.03–53.65 mg/g (HLS). A greater affinity and more favorable association between Cd(II) and HLS is observed via fitting models. The incorporation of LS provides HLS with significantly better adsorption properties toward Cd(II) than α-Fe2O3, as is further confirmed by FT-IR and XPS characterization. Fe-O-O-H and Fe-O-H structures as well as more hydroxyl groups are observed, which promote the adsorption performance since the process are mainly influenced by complexation via coordination bonds.

Заразительное рядом: о некоторых аспектах методологии и терминологии почвенных исследований и публикаций

The article discusses some examples of incorrect methodology and terminology practice in soil research and publications. In particular, the authors draw attention to extremely inflated and unjustified use of the phrase “statistically significant”, to the controversy between the chemical determination and terminological definition of soil humus, to the inadequacy of using mass concentrations of chemical elements to inferring soil organic matter stoichiometry, to frequent interpreting empirical regression as if describing some conceptual relationship, to the principle impossibility to estimate bacteria and fungi numbers in soil by agar plate counts of colony-forming units. Based on the discussed examples, the authors conclude that the ease and the rate of the present-day communication flow will increasingly enhance the role of communication exchange in estimating the validity of results of a certain piece of scientific cognition, which will significantly increase the negative impact of consensuality, especially in soil science, as soil is one of the most complex natural bodies.

Ecological analysis of agricultural environmental management problems in the Central Chernozem Region

Abstract. Land resources of the Central Chernozem Region are intensively used in economic activities that have affected the degradation of the natural environment components. The 100-year observation period revealed changes in biogenic components and humus in the regions soils. To determine the environmental problems of agricultural environmental management, we have calculated modular indicators of geochemical impact of various agricultural sectors. We have calculated the modular indicator of agricultural impact assessment on agricultural systems of the Central Chernozem Region. In order to preserve land resources it is important to quantify the impact of agricultural production. To assess the impact the authors have introduced three types of coefficients: taking into account the agricultural, livestock and technogenic impact. They can be used as the main diagnostic indicators to identify environmental problems. The coefficients make it possible to determine trends in environmental management and by the results of geochemical analysis environmental problems and the degree of impact of different types of agricultural production are identified. Balance violations of the substances cycle in forest-steppe landscapes have been revealed. The landscape and geochemical approach reveals migration processes, the cycle of substance and violations of self-regulating properties of the natural landscape. The analysis of potassium and phosphorus distribution is important in agrochemical aspect. The coefficient was calculated based on the mass of matter introduced and removed from the soil in relation to their content in the soil. The degree of geochemical agricultural impact exceeds the natural geochemical background. It gives an opportunity to define negative features of agricultural nature use. A complex geochemical analysis of different nature users will make it possible to determine the degree of their impact on the natural environment in the region. Soil transformation in agrosystems is accompanied by ecological losses both for the natural environment and for life activity of the population. Due to wide application of chemicalization means for implementation of the agricultural intensification program, it became necessary to determine quantitatively the geochemical load on the landscape in order to optimize and protect it. In this regard, issues of renewal of natural material and energy resources are relevant for agricultural production.

Effects of lime application on nitrogen and phosphorus availability in humic soils

There is a paucity of information on nitrogen (N) and phosphorus (P) mineralization in humic soils, which are highly weathered and have high carbon (C) (>1.8%). This study was to determine effects of liming on N and P mineralization in humic soils. Lime was applied to reduce acid saturation to 20% of the 0–10 and 10–20 cm depths of soils from Eston and Eshowe. Soils were incubated at field capacity moisture and 25 °C temperature, with destructive sampling after 0, 7, 14, 21, 28, 56, 84 and 112 days. Samples were analysed for pH, ammonium- and nitrate-N and extractable P. Phosphorus pools and soil microbial biomass C and N (SMBC and N) were analysed after 112 days only. Soil pH increased up to day 7 and decreased thereafter in Eston soil but decreased throughout the incubation in Eshowe soil. Ammonium- and nitrate-N increased with lime rate, with ammonium-N peaking after 7 and 14 days for Eston and Eshowe soils, respectively. The 0–10 cm depth had higher ammonium-N than 10–20 cm for both soils. Nitrate-N increased with corresponding decrease in ammonium-N. Extractable P decreased till day 21 and increased thereafter in Eston soil, with slight changes in Eshowe. Higher lime rate decreased Al-P, Fe-P and CBD-P and increased soluble-P, Ca-P, and SMB-C and N for both soils. The findings imply that liming humic soils increase nitrate-N and, to a lesser extent, extractable P, possibly improving productivity and exposing N to leaching.

Humus balance in a short crop rotation of Right Bank Forest Steppe of Ukraine depending on fertilization systems of typical chornozemic soil

Four year research (2015–2018) at Bila Tserkva National Agrarian University proved that plant residues and non-market products of the field five course grain row rotation are important sources for soil humus formation. On the unfertilized areas, fertilized withn8 t/ha of animal manure + N76P64K57, 12 t/ha of animal manure + N95P82K72 and 16 t/ha of animal manure + N112P100K86 humus percentage formed due to humification of plants matter was correspondently 51.4; 40.3; 37.7 and 36.1 %, with animal manure – 0; 15.3; 17.2 and 18.7 %, with by-products of farming – 44.0; 40.8; 41.7 and 42.1 %, with herbage of white mustard – 4.6; 3.6; 3.4 and 3.1 %. With the increase of fertilizers level this index regarding plants matter and green manure decreases, while animal manure provides for the index slight increase. On the unfertilized areas humus balance under cultivated crops as sunfl ower and corn is negative, but under other crops in rotation it is positive. On the fertilized areas under all crops this index is positive. When applying the biggest amount of fertilizers, annual gain in soil humus is 1.1 t/ha. Humus balance is negative on all the variants of research under the condition of disposal of non-market products from the fi elds of crop rotation. Along with plants matter, plant by-products and herbage of white mustard the amount of humus provided to the soil was equal to the application of correspondently 14–33, 12–36 and 1.3–2.6 t of animal manure per hectare of tilled fi eld. Under zero, the fi rst, the second and the third levels of soil fertilization, soil received correspondently 4.08; 5.98; 7.46 and 8.73 t of plants matter 68–71 % of which are root and the others are above surface. The percentage of by-products of crops in the rotation increases with fertilizers amount increase. Soy, winter wheat, sunfl ower and spring barley have a bigger gain in above surface rather than root mass due to increase of fertilizers amount. The highest productivity from one hectare of tilled fi eld in a crop rotation (5.63 t of dry matter, 7.84 t of fodder units, 0.671 t of digestible protein) is gained due to application of 16 t/ha of animal manure + N112P100K86, though the most economically viable amount is 12 t/ha animal manure + N95P82K72. Key words: humus balance, soil, fertilizers, crop, by-products, plants matter, crop rotation, grain crops, index of ecologization, productivity.

Application of a water infiltration model for simulating water repellency of humus soil

AbstractOne‐dimensional infiltration experiments were conducted using hydrophilic and water‐repellent soils from the Guishui River Basin to study the effects of soil water repellency on cumulative infiltration (CI) and the infiltration rate (IR). The test results show that, for the hydrophilic soil (HS) sample, CI increases monotonously with time and IR decreases monotonously. For the water‐repellent soil (W‐RS), however, the following characteristics were observed: (a) There is an inflection point in CI and a sudden increase in IR. Larger values of the initial soil water content produce an earlier and more significant inflection point in CI, and a larger peak value of IR. (b) The post‐peak stable IR is greater than the pre‐peak value, ignoring the beginning of rapid infiltration, and the overall IR presents a single peak. The applicability of various water infiltration models was analysed for the two soil types. Numerical analysis suggests the following conclusions: (a) For both HS and W‐RS, the Kostiakov function, Gamma function, and Beta function (BF) models exhibit good applicability. (b) For W‐RS, the Gauss function model not only reflects the monotonous decrease in IR, but also produces a steady IR in the initial stage, a gradual increase before the peak value, and a gradual decrease after the peak value. Similarly, the BF model reflects the monotonous decrease in IR. A piecewise BF reproduces the U‐shaped change in rapid infiltration before the inflection point, as well as the gradual increase and right‐skewed distribution curve of W‐RS infiltration before and after the inflection point. The BF model achieves the best simulation accuracy and has the widest applicability.

The feed base formation of an agricultural enterprise with using of digital technologies

The issues of planning the feed base of an agricultural enterprise, taking into account the productivity of the livestock sector have been considered in the paper. The developed program is a single interconnected system with two blocks of tasks: animal husbandry and crop production. This connection allows us to make multivariate calculations that ensure the most rational use of acreage and material resources on the basis of an integrated approach to the design of the feed base, taking into account natural, organizational, economic and technological factors. Based on the example of the agricultural enterprise in the Ryazan region that specializes in the production of dairy and crop products, a calculation for planning the output of livestock products has been made, taking into account the necessary land resources to provide high-quality animal feed. Based on the annual structure of the ration, taking into account the summer and winter stall housing, the need for acreage for forage crops grown by the farm has been determined, which amounted to 582 ha. The planned productivity of dairy cattle was equal to 5000 kg per lactation. At the subsequent stages the need for organic, mineral, lime and micro-fertilizers has been determined, providing the necessary level of productivity of feed crops, provided that the humus of the soil is not deficient. Based on the proposed structure of the annual ration and the calculated share of perennial grasses (53,44 %), a positive dynamics of soil humus was obtained for the crop rotation as a whole. The inclusion of perennial grasses in the crop rotation will allow the farm to ensure planned production of livestock products while maintaining a deficit-free balance of soil humus. According to the supply of nitrogen given the crop need additional introduction of ammonium nitrate in the amount of 839,7 centners. In addition, calculations have been made according to the requirements of lime fertilizers, which found that the specified area must input dolomite 2219,8 t. Also the doses of mineral fertilizers required to obtain the planned yields of crops have been calculated. The use of the developed software product allowed us to determine the need for boron–containing fertilizers – 1,08 centner, manganese – 3,38 centners and copper-containing – 0,46 centner.

Humic Acid Transformation by the Fungus Cerrena unicolor Growing on Cellulose and Glucose

Microbial degradation of lignocellulose and soil organic matter is an important process controlling CO2 flow into the atmosphere, which is mostly carried out by fungi. The alkali-soluble fraction, which is represented mostly by the so-called humic acids (HA), dark-colored compounds of phenolic nature, constitute ~30‒70% of soil Corg. This is the first report on efficient degradation of soil HA under cellulolytic conditions; cellobiose dehydrogenase (CDH), an oxidative enzyme of the cellulolytic complex, was shown to play the key role in this process. Growth of a wood-decomposing fungus Cerrena unicolor on cellulose (CDH and laccase production) and glucose (laccase production) resulted in HA decolorization by 60 and 20%, respectively. HA depolymerization in the presence of CDH and its polymerization in the presence of laccase were shown by gel filtration experiments with the culture liquid and pure enzyme preparations. HA degradation in the presence of CDH was inhibited by radical scavengers, indicating the radical nature of this process (probably the Fenton’s reaction). HA depolymerization by CDH decreased in the presence of laccase, while HA polymerization by laccase decreased in the presence of CDH. Thus, the interaction of these enzymes affects HA transformation under cellulolytic conditions. These results improve our understanding of the mechanisms of microbial degradation of the aromatic components of soil humus and of the ecological functions of wood-decomposing fungi grown under cellulolytic conditions.