Main Soil Types Research Articles

Molecular Detection of Cyclospora cayetanensis in Two Main Types of Farm Soil Using Real-Time PCR Assays and Method Modification for Commercial Potting Mix.

Cyclospora cayetanensis is a foodborne protozoan parasite that causes outbreaks of diarrheal illness (cyclosporiasis) with clear seasonality worldwide. In the environment, C. cayetanensis oocysts are very robust, and contact with contaminated soil may serve as an important vehicle in the transmission of this organism, and it is considered a risk factor for this infection. The present study evaluated a flotation concentration method, previously shown to provide the best detection results when compared with DNA isolation directly from soil samples, in two main types of farm soil, silt loam soil and sandy clay loam, as well as in commercial potting mix samples inoculated with different numbers of C. cayetanensis oocysts. The flotation method was able to detect as few as 10 oocysts in 10 g of either type of farm soil without modifications, but needed an extra wash and samples of reduced size for the processing of the commercial potting mix to be able to detect 20 oocysts/5 g. A recently modified real-time PCR method for the detection of C. cayetanensis based on a mitochondrial gene target was also evaluated using selected samples of each type of soil. This comparative study confirmed that the concentration of oocysts in soil samples by flotation in high-density sucrose solutions is a sensitive method that can detect low numbers of oocysts in different types of soil.

Particle Size Distribution and Depth to Bedrock of Chinese Cultivated Soils: Implications for Soil Classification and Management

Although a number of studies have provided information on soil texture, soil classification, and depth to bedrock throughout China, few studies have combined this information, which is the basis for agricultural field management. A total of 81% of China’s cultivated lands are distributed among the Middle–Lower Yangtze Plain (18.2%), arid and semiarid North China Plain (18.2%), Northeast Plain (17%), Huang-Huai-Hai Plain (16.1%), and Yunnan–Guizhou Plateau (11.6%). The Huang-Huai-Hai Plain has the highest density of agricultural land (58.5%) and the greatest depth to bedrock of cultivated land (243–402 m). The lowest cultivated depth to bedrock (4–84 m) is concentrated in the Sichuan Basin and its surrounding regions. The main cultivated soil types are Anthrosols, Fluvisols, Cambisols, Phaeozems, Luvisols, Kastanozems, Leptosols, and Acrisols, under the main topsoil texture classes of loam, clay loam, silty clay loam, silt loam, sandy loam, and clay. The Fluvisols had the largest depth to bedrock (156 m) on the Middle–Lower Yangtze Plain and Huang-Huai-Hai Plain, with the highest silt soil distributions but comparable lower sand contents. The Yunnan–Guizhou Plateau had the highest clay soil content. The cultivation under Kastanozems and Leptosols on the Qinghai–Tibet Plateau and in arid and semiarid North China and under Phaeozems on the Northeast Plain should be restricted and managed very cautiously facing erosion risk. The higher percentages of Anthrosols are on the Middle–Lower Yangtze Plain (37%), in Southern China (32%), and on the Yunnan–Guizhou Plateau (26%). The same cultivation aim (i.e., more crop 0production) has produced a similar range of properties over time among the soils developed on agricultural fields, which are classified as Anthrosols. However, various soil types can still be found in agroecosystems because of the variations in climate and topography. Our results highlight that the agriculture-based soil climate and topography shape the interaction of the soil development and not only the pedogenic history of the soil development under variations in the soil depth to bedrock but also the cultivation of distinct pedogenic features. This study provides cultivated soil information on the depth to bedrock, soil classification, and soil texture in China, as well as instructions for field strategies for sustainable agricultural development.

Elemental chemical composition of soils and plants of Northern Yakutia, its ecological and biogeochemical assessment

This study investigated the composition and properties of the main soil types in the natural biogeocenoses of tundra and taiga in the coastal lowlands of the Arctic zone of Northern Yakutia. We have identified the total content of biologically important chemical elements in the soils and resource plants (N, P, K, Ca, Mn, Zn, Cu, Co, Mo, B, As, Be, Cd, Cr, Ni, Pb, Hg, V, Sb, and Sr), and the concentration of mobile forms of S, P, K, Fe, Mn, Zn, Cu, Co, Cd, Cr, Cr, Ni, and Pb in different extractants. We also specified the influence of soil composition and properties on the content of macro- and microelements. Various mobilities of chemical elements in soils and their availability to plants have been revealed. The amounts of chemical elements in the studied soils and plants were estimated according to agrochemical, biogeochemical and hygienic criteria and standards.

DESCRIPTION OF THE STUDY OF SOILS IN DIDACTIC BOOKS FOR THE EARLY YEARS OF ELEMENTARY SCHOOL

Background: The "soil" content is presented gradually in the early years of elementary school, one of the resources most used as support in basic education is the textbook, which through the National Plan of Book and Didactic Material, was evaluated carefully before being released for selection of schools and education professionals. Aim: This study aims to describe aspects of the "soil" content in four science textbooks for the third year of elementary school. Methods: Documentary analysis followed Bardin’s model. In the pre-analysis, the materials were organized in L1, L2, L3, and L4 followed by floating reading to identify the descriptive and content support elements. The practical activities were classified according to Campos and Nigro, based on the participation of students and teachers in their development. The images were analyzed based on Gestalt pregnancy theory. Results: The analyzed books present respectively 18, 30, 18, and 17 pages destined to the content, where it was possible to identify the presence of definitions, practical activities, and contextuality of the images, although some have neglected relevant aspects. Discussion: The materials use different methodologies, which favor the cognitive development of the student. However, none of the books has information on the main types of soils in Brazil besides presenting limitations on soil classification and science. Conclusion: We conclude that the textbooks of elementary school analyzed present the soil content in its structure, with definitions through texts and images, to an appropriate extent and present relevant proposals for practical activities.

Bridging the gap from hydrological to biogeochemical processes using tracer-aided hydrological models in a tropical montane ecosystem

How simple or complex catchment models need to be is still unclear particularly for tracer-aided models that go beyond hydrograph fitting. Here, we take advantage of a sub-daily hydrometric and tracer data set from a tropical montane (páramo) experimental catchment to fill this knowledge gap. We evaluated six conceptual rainfall-runoff model structures with different complexity that represent the perceptual understanding of the catchment's hydrological functioning. The models solved conservative and reactive tracer mass balances to simulate streamflow, stable isotopes, and DOC concentrations and were assessed for performance and parsimony using three calibration targets (discharge only, discharge and stable isotopes, and discharge and DOC), resulting in 18 model configurations. Although all models satisfied the discharge calibration (KGE > 0.8), differences arose when considering tracer transport. The more complex models outperformed the simpler ones in terms of goodness-of-fit and parsimony, indicating that the catchment streamflow response consisted of quick near-surface flow and tracer contributions, more mixed flow through the two main soil types (Andosols and Histosols), as well as flow from the well-mixed shallow fractured rock (up to 20 m depth). The bedrock flow pathway contributed up to ∼25% of total flow during baseflow conditions. This study provides a benchmark experiment to identify hydrological and biogeochemical behavior in tropical montane catchments using relatively parsimonious tracer-aided hydrological models.

The soil trail of Buscagna Valley, an example of the role of soil science in geodiversity and geoheritage analyses

Abstract Soil is a component of geodiversity and, for its scientific value, can also be a component of geoheritage, playing a role in reconstructing the environmental evolution of an area. This assumption will be examined here with special reference to mountain environments, where the high variability of soil forming-factors is responsible for a great variety of soil types, contributing to soil diversity and to local geodiversity. To promote soil as an element of geoheritage, we propose a strategy for creating a trail about soil topics in the Buscagna small mountain catchment in the Veglia–Devero protected area (Lepontine Alps, Italy). Geopedological research carried out in the study area has allowed the identification of seven soil profiles as sites of potential pedological interest along already existing hiking paths. The selected soil profiles mirror the main soil types of the area and testify to past environmental conditions and geomorphic dynamics. Among these, two soil profiles are also selected as pedosites. Providing hikers and mountaineers with a proper key to read exposed soils along the Buscagna Valley, the trail allows an increase in awareness of geoheritage conservation with a focus on soil in mountain landscapes, where soil characteristics reflect the influence of compound forming-factors.

The Effect of Biostimulants on the Productivity of Perennial Grasses Grown on the Main Types of Soils

The Effect of Biostimulants on the Productivity of Perennial Grasses Grown on the Main Types of Soils

Artisanal Mining and Soil Quality in the Sudano-Sahelian Climate: Case of the Artisanal Mining Site of Yimiougou in Burkina Faso, West Africa

The majority of the population of Burkina Faso lives from agriculture and therefore depends on the land. The main objective of this study is to assess the quality of the soils in the area linked to artisanal mining activities. The methodology adopted consisted in sampling and characterizing the main types of soil. In order to assess the level of soil pollution by artisanal mining, parameters such as the geo-accumulation index (Igeo) and the contamination factor (CF) are calculated. A prediction of acid mine drainage (AMD) was also carried out on samples of mine tailings which are potential sources of pollution of these soils. The results obtained show that the soils in Yimiougou are of nil to low agronomic interest. The Igeo shows that for lead, copper, zinc and arsenic the levels found in the different morphological units are partly attributable to human action and specifically artisanal mining. The values of the contamination factor indicate contamination. Cobalt presents the lowest contamination. For cadmium, the different types of soil are moderately contaminated except for the FITLC type, which has a CF value of 0.50, therefore synonymous with low or absent contamination. The various morphological units studied are very heavily contaminated with zinc, copper, lead and arsenic. The pH and conductivity values indicate that the mine tailings samples are non-acidogenic, therefore not yet oxidized. As for the sulphide contents, they show that only samples S17, S22, S23 and S24 present values that are strictly above the threshold (0.3%) and therefore potentially acid-generating. The comparative study of the acid potential (AP) and the neutralization potential (NP) reveals that the neutralization potentials of the different samples are clearly higher than the acid potentials even for the samples which present a proven acidification potential (S17, S22, S23 and S24). These results show that the mine tailings have the natural capacity to neutralize any possible mine drainage, given the presence of acid-eating minerals such as the carbonates associated with the mineralization.

A dataset of Gansu soil species based on the Second National Soil Survey

Based on the results of the Second National soil Survey, Gansu Soil Species was established to accumulate systematic, standardized and quantitative data of soil classification as a solid foundation for the development of soil science in Gansu province.This dataset is based on the processing and integration of Gansu Soil Species published by Gansu Science and Technology Press in 1992. The original data and information of 285 soil species in the book (e.g. attribution and distribution, main characters, production performance summary, physical and chemical properties of profiles) are extracted and collected in a standardized, structured and digital way, integrated with 8 specialized subject data tables indexed by species ID and species name, and conducive to the development of online query, including soil species classification, distribution and characteristics of main soil types, basic information and distribution of soil species, sampling sites and occurrence layers of typical profiles, statistical physicochemical properties of typical profiles and soil species profiles, etc. This dataset can be widely used in regional land quality assessment, environmental effect research, soil carbon storage research, etc., providing significant scientific support for the promotion of new agricultural technology and rational utilization of soil resources.

X-ray microtomography analysis of urban soils of the Rostov region

Urban soils are exposed to transformations of physical properties which are not captured by the conventional approaches due to the presence of impurities that can distort the obtained data. Advanced visualization techniques such as X-ray computed tomography (CT) offer new opportunities of exploring heterogeneity of soil properties at horizon or aggregate scales. The studies of the structure and pore space of different types of urban soils formed on chernozems were carried out using a SkyScan 1172G tomograph. The tomographic study was carried out in the humus-accumulative horizons for six main types of urban soils. The volumetric parameters for the pore space were calculated, and pores orientation and shape parameters were calculated in 2D sections. The closed pore value was obtained as the most informative diagnostic indicator of the urban soils structural condition. A morphometric analysis of the shape and orientation of fine soil macropores with a diameter of 0.3–2.0 mm also showed significant structural differences between natural soils under woody or grassy vegetation and urban anthropogenically transformed soils. All studied soils at the aggregate scales slightly differ from each other in the value of the internal aggregate tomographic porosity. This shows that the compaction because of anthropogenic transformation occurs due to the interaggregate pore space. At the aggregate porous spaces, no changes can be traced.

Variety and action of soil microorganisms in diverse Ukraine climatic zones

The study aims to summarize the important results of the long-term studies of soil microorganisms: structure, interaction, functioning, activity, and diversity in the main types of soils in different natural and climatic zones of Ukraine. Methods for the study are the generalization and analysis of literary sources and scientific papers, and materials, as well as our own research. The initial information for the assay’s calculations, matheanalysis were the resokution of many year discovering of soil microorganisms in the period 2005-2021. The researches have shown a powerful action and diversity of soil microorganisms of the ecosystems. The Chernozem of the Steppe zone was characterized by a more stable and balanced structure of microbiocenosis, processes of mineralization-immobilization, decomposition of organic matter, and humus accumulation than the sod-podzolic, forest soils of Polesie. Studies of soil microbiome showed a direct correlation between natural conditions and soil treatment methods and the activity of microbiocenoses, a decrease in the biodiversity of bacterial groups through the use of plowing. The increase in the proportion of micellar organisms occurred with the prolonged application of mineral fertilizers.

Response of bacterial community composition and co-occurrence network to straw and straw biochar incorporation.

Microbial decomposition plays a crucial role in the incorporation of straw and straw biochar (SSB) into soil. Lime concretion black soil (LCBS) is a typical low-medium crop yield soil, and it is also one of the main soil types for grain production in China. However, the link between SSB additions and soil bacterial communities in LCBS remains unclear. This study explored the effects of SSB incorporation on bacterial community composition, structure and co-occurrence network patterns at different soil depths and maize growth stages. The results showed that soil PH, soil organic matter and total nitrogen significantly affected the seasonality and stratification of the soil bacterial community. The composition and diversity of bacterial communities were significantly affected by growth period and treatment rather than soil depth. Specifically, the bacterial community diversity increased significantly with crop growth at 0–20 cm, decreased the relative abundance of Actinobacteria, and increased the relative abundance of Proteobacteria and Acidobacteria. SF (straw with fertilizer) and BF (straw biochar with fertilizer) treatments decreased bacterial community diversity. Co-occurrence networks are more complex in BF, S (straw), and SF treatments, and the number of edge network patterns is increased by 92.5, 40, and 60% at the maturity stage compared with F (fertilizer) treatment, respectively. Moreover, the positive effect of straw biochar on the bacterial network pattern increased with time, while the effect of straw weakened. Notably, we found that rare species inside keystone taxa (Gemmatimonadetes and Nitrospirae) play an indispensable role in maintaining bacterial network construction in LCBS. This study offers a comprehensive understanding of the response of soil bacterial communities to SSB addition in LCBS areas, and provides a reference for further improvement of LCBS productivity.

AGROCHEMICAL PROPERTIES OF SOILS OF REPUBLIC OF MORDOVIA

The global nature of anthropogenic activity leads to profound and in some cases irreversible changes in biogeochemical cycles. The purpose of the work is to monitor the soils of the Republic of Mordovia. Initial parameters of the studied soils were used as a reference standard,in its relation the state of the soil cover was assessed.Mordovskiy State Center of Agrochemical Service has been conducting a system of regular observations on reference plots on the territory of the republic since 1993. They are located in different natural and climatic zones and reflect natural and climatic features of the main soil types. Organic matter accumulates on the soil surface and all upper horizons in the process of soil formation. For different soil types, there is a different ratio of the processes of supply of plant and animal residues and the processes of their transformation, and different intensity of these processes. The weighed mean content of humus was 7.6%, dark gray forest soils - 5.4%, gray forest soils - 3.9% and on alluvial soils - 4.7% on leached and podzolized black soils of the Republic of Mordovia. Soil samples of all soiltypes were taken in early spring before the start of spring field work (continuous survey), the results of their analyzesallow to assess their available nitrogen. Black soils and dark gray forest soils of the Republic of Mordovia are generally characterized by favorable physical and chemical properties: slightly acidic - close to neutral reaction of the medium, a relatively high amount of absorbed bases. Agrochemical properties of gray forest and soddy-podzolic soils worsen compared to those mentioned above. The content of mobile phosphorus and exchangeable potassium in the studied soils varies from low to very high, being average in most areas. Their content is determined not only by the soiltype, but also by soilcultivation state and application of mineral fertilizers.

Characteristics of humus content on different soil types of Zdolbuniv district of Rivne Region

The dynamics of changes in the humus state of the soils of Zdolbuniv district during the V–XI rounds of agrochemical survey were analyzed. The state of biologization of agriculture, in particular the plowing of siderates, the introduction of straw and manure and the use of peat over the last 8 years in the studied area, is highlighted. Mandatory biologization of agriculture, taking into account the biological features of each crop, in particular, plant needs for nutrients, indicators of potential and effective soil fertility, its physical and chemical properties, assortment and chemistry of fertilizers, climatic conditions in a zonal section — comprehensive implementation of these measures will contribute to a significant increase soil fertility of the district’s agricultural lands, in particular improving its humus condition. Since an important reason for the lack of accumulation of humus reserves in the studied soils is the unsatisfactory state of biologicalization of agriculture in the area. Conclusions and suggestions on improving the humus condition of the soils of the studied area have been prepared. It is established that according to the results of agrochemical studies of agricultural lands of Zdolbuniv district of Rivne region for the XI round of agrochemical certification of agricultural lands, the weighted average humus content is 2.6% and corresponds to the average content. It was found that the studied soils of the district are characterized by very low and low (less than 2.1%) — 0.86 thousand hectares (10.0%), medium (from 2.1 to 3.0%) — 6.14 thousand hectare (71.7%), elevated (from 3.1 to 4.0%) — 1.5 thousand hectare (17.5%), high and very high (> 4%) — 0.06 thousand hectare (0.7%) humus content. In terms of the main types of soils, the highest humus content in meadow soils, meadow and chernozem soils, chernozem and meadow soils with content of 3.3% and on chernozems typical and chernozems strongly degraded of different degrees of erosion with an average humus content of 2.8%. It should be noted that the dynamics of humus content in the soils of Zdolbuniv district of Rivne region for the last 10 years of research shows the process of its stabilization and increase from 2.2% in 2007 to 2.6% in 2017. Comparing only the area of land plots, which were surveyed in three rounds — 2007, 2012 and 2017, the humus content is 2.5; 2.5 and 2.6%, respectively, which confirms the stabilization of the humus content over the past ten years of agrochemical research. An important reason for the lack of accumulation of humus reserves in the studied soils is the unsatisfactory state of biologization of agriculture in the area.

Combination of3D Fluorescence/PARAFAC and UV-Vis Absorption for the Characterization of Agricultural Soils from Morocco.

The present study, combining UV-Visible absorption and 3D fluorescence supported by PARAFAC chemometric analysis, focused on the characterization of soil water extractable organic matter (WEOM) in the zone of Doukkala located near the Atlantic coast of Morocco. The extracts, in water, of a set of 30 samples covering the four main types of agricultural soils in the region (commonly labeled Tirs, Faid, Hamri and R'mel) were investigated. [Formula: see text] and [Formula: see text] absorbance ratios [Formula: see text] and [Formula: see text] spectral slopes, along with their ratios[Formula: see text], as well as the fluorescence [Formula: see text] and humification [Formula: see text] indices were calculated and interpreted. In the four soil types, these parameters revealed, on the one hand, organic materials of terrigenous origin with some biological component, and showed, on the other hand, that these materials are in similar stages of humification with an important humic character. In all the soils investigated, 3D fluorescence crossed with PARAFAC chemometrics highlighted the absence of any protein component and revealed the prevalence of the fulvic acids fraction in the organic matter humic material.

AGRICULTURAL PRODUCTION CHARACTERISTICS OF SOILS IN THE SOUTH SLOPE OF THE GREAT CAUCASUS ON THE EXAMPLE OF THE SHEKI DISTRICT OF AZERBAIJAN

The article presents the results of soil-ecological and geobotanical studies of the main types of soils in the Sheki region, describes the natural conditions and diagnostic indicators of soils in vertical zoning from intrazonal landscapes to subalpine meadows.

Distinct Denitrifying Phenotypes of Predominant Bacteria Modulate Nitrous Oxide Metabolism in Two Typical Cropland Soils.

Denitrifying nitrous oxide (N2O) emissions in agroecosystems result from variations in microbial composition and soil properties. However, the microbial mechanisms of differential N2O emissions in agricultural soils are less understood. In this study, microcosm experiments using two main types of Chinese cropland soil were conducted with different supplements of nitrate and glucose to simulate the varying nitrogen and carbon conditions. The results show that N2O accumulation in black soil (BF) was significantly higher than that in fluvo-aquic soil (FF) independent of nitrogen and carbon. The abundance of most denitrifying genes was significantly higher in FF, but the ratios of genes responsible for N2O production (nirS and nirK) to the gene responsible for N2O reduction (nosZ) did not significantly differ between the two soils. However, the soils showed obvious discrepancies in denitrifying bacterial communities, with a higher abundance of N2O-generating bacteria in BF and a higher abundance of N2O-reducing bacteria in FF. High accumulation of N2O was verified by the bacterial isolates of Rhodanobacter predominated in BF due to a lack of N2O reduction capacity. The dominance of Castellaniella and others in FF led to a rapid reduction in N2O and thus less N2O accumulation, as demonstrated when the corresponding isolate was inoculated into the studied soils. Therefore, the different phenotypes of N2O metabolism of the distinct denitrifiers predominantly colonized the two soils, causing differing N2O accumulation. This knowledge would help to develop a strategy for mitigating N2O emissions in agricultural soils by regulating the phenotypes of N2O metabolism.

AGRICULTURAL PRODUCTION CHARACTERISTICS OF SOILS IN THE SOUTH SLOPE OF THE GREAT CAUCASUS ON THE EXAMPLE OF THE SHEKI DISTRICT OF AZERBAIJAN

The article presents the results of soil-ecological and geobotanical studies of the main types of soils in the Sheki region, describes the natural conditions and diagnostic indicators of soils in vertical zoning from intrazonal landscapes to subalpine meadows.

Identification of soil particle size distribution in different sedimentary environments at river basin scale by fractal dimension

The geomorphology of river basin is complex, and its soil sedimentary characteristics are poorly defined. To study the spatial variability of soil structure in different sedimentary environments at the basin scale, 356 sets of soil samples were collected from five typical sedimentary environments in the Yellow River Basin and the Haihe River Basin, including the upper and lower reaches of the rivers, mountain-front plains, central alluvial plains and eastern coastal plains. The particle size distribution (PSD) of the soil samples was obtained using a laser particle size analyzer, and the fractal dimension (D) of the soil structure was derived by applying fractal theory. The PSD, D and the correlation between them were analyzed by the Pearson correlation method for typical sedimentary environments in two basins. The results show that: (1) The main soil types in the typical geological environments in the basin are sand, loamy sand, sandy loam, silty loam, and silty soil. The soil particle size in the upper and lower reaches of the rivers was higher than that in the plain areas. (2) In the plane, The D value descended in different regions in the following order: the mountain-front plain > the eastern coastal plain > the upper Yellow River > the central alluvial plain > the lower Yellow River. In the vertical direction for both rivers, the D value showed a decreasing trend with increasing burial depth. (3) The model results showed a cubic polynomial correlation between D values and PSD, which was closely related to the non-uniformity of particle size during sorting and deposition. The soil PSD and fractal characteristics are effective tools for the quantitative evaluation of soil structure in various sedimentary environments in the basin.

Agricultural Production Characteristics of Soils In The South Slope of The Great Caucasus On The Example of The Sheki District of Azerbaijan

The article presents the results of soil-ecological and geobotanical studies of the main types of soils in the Sheki region, describes the natural conditions and diagnostic indicators of soils in vertical zoning from intrazonal landscapes to subalpine meadows. “We need to clearly realize that the anthropogenic transformation of the biosphere in a certain sense has the character of a global catastrophe and the anthropogenic landscape is the landscape of the future. In all likelihood, within 100 - 200 years it will occupy the entire territory of the earth's surface, with the exception, perhaps, of eternal ice and mountain peaks. The reasons for this lie in the uncontrolled and progressive growth of the population of the Earth, in the non-stop growth of industry and agriculture, in the constant human need for energy sources, and other processes accompanying the “triumph of civilization” [7].