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As conservation tillage becomes one of the foundations of sustainable crop production, important questions arise about its value, which needs to be defined and evaluated. One of the most important indicators of soil compaction is penetration resistance (PR), which comes as a short-term response to the state of soil physics. The objective of this work is to compare different tillage treatments (TT) on soil compaction on silty clay loam Stagnosol and silt Gleysol in the continental part of Croatia. The research included three tillage treatments: ST—conventional tillage, CTD—deep conservation tillage, and CTS—shallow conservation tillage. PR was determined on each soil depth of 5 cm up to 80 cm, and measuring was provided on two measuring dates. The obtained results showed a higher influence of the year factor than TT. In the upper layers (up to 35 cm), PR values between TT were with significant differences, but in most cases below root-limiting critical values, while in deeper soil layers (35–80 cm), we found that penetration values on each tillage treatment begin to stabilize and smooth out in most cases, with similar dynamics on both soil types and measurement dates. In most of the cases, the highest PR was measured for conservation treatments in wetter soil conditions. [ABSTRACT FROM AUTHOR]

The soil nematode communities in typical tundra soils of southern Chukotka have been analyzed. Five types of shrub and grass-shrub biotopes on Cryosols, Fluvisols, Histosols, Gleysols, and Cambisols were examined. The animals were extracted from the soil by the Baermann technique with subsequent determination of taxonomic diversity, total and relative abundance, and trophic groups. The highest number (7044 individuals/100 g of soil) and biomass (12.15 mg) of nematodes were found in the Histosol, and the minimum one (1000 individuals/100 g of soil; 1.96 mg) of nematodes in the Cryosol. Bacterivorous nematodes dominated in all soil types. The maximum percentage of bacterivorous nematodes (94%) were found in the Cambisol. The percentages of fungivorous nematodes in the studied soils ranged from 1 to 42%. Predatory and omnivorous nematodes were present in all soils except for the litter of the Cambisol. Their percentage ranged from 2 to 32%. Phytonematodes were few, their highest number was found in the Gleysol (18%). The nematode fauna of the soils under analysis differed significantly. The greatest diversity of nematodes was found in the peat horizon of the Fluvisol, and the smallest diversity of nematodes was recorded in the litter of the Cambisol. The values of Sigma Maturity Index ranged between 2 and 3. The Enrichment Index had low and moderate (1.40–41.02) values, and the Structure Index had high values (59.51–84.07). The Eudorylaimus and Plectus genera were eudominants in all soil types. The soil food webs formed in the biocenoses under consideration can be characterized as stable and structured except for the alder biocenosis. [ABSTRACT FROM AUTHOR]

Red onion is an important food commodity, so production land needs to be maintained. If the land productivity decreases, it has the potential to be converted into other land uses. The largest red onion production center in Indonesia is in Brebes Regency, which is developed on various soil types with different characteristics. The differences in soil types have shown differences in production. As a bulb plant, red onion requires a good planting media (soil tilth), including soil consistency and the ability to swell and shrink the soil. Therefore, this research was to examine the role of soil tilth characteristics and the ability of soil swell and shrink on red onion productivity. The research was carried out through the stages of surveying red onion development locations in Brebes Regency, collecting production data in various soil types in production centers, analyzing soil properties especially soil consistency and COLE (coefficient of linear extensibility), and analyzing the relationship between soil properties and red onion production. The results showed that red onion cultivation in Brebes Regency were planted on Cambisol Eutrik, Gleysol Eutrik and Mediterannean Haplik. Cambisol Eutrik has the highest red onion productivity followed by Mediterannean Haplik and Gleysol Eutrik. The consistency and COLE value were different among soil types. . The plasticity index, tillage range, and COLE value were influenced by the clay and soil organic matter content. The higher clay and the lower organic matter content, the poorer soil tilth and the lower production. [ABSTRACT FROM AUTHOR]

As conservation tillage becomes one of the foundations of sustainable crop production, important questions arise about its value, which needs to be defined and evaluated. One of the most important indicators of soil compaction is penetration resistance (PR), which comes as a short-term response to the state of soil physics. The objective of this work is to compare different tillage treatments (TT) on soil compaction on silty clay loam Stagnosol and silt Gleysol in the continental part of Croatia. The research included three tillage treatments: ST—conventional tillage, CTD—deep conservation tillage, and CTS—shallow conservation tillage. PR was determined on each soil depth of 5 cm up to 80 cm, and measuring was provided on two measuring dates. The obtained results showed a higher influence of the year factor than TT. In the upper layers (up to 35 cm), PR values between TT were with significant differences, but in most cases below root-limiting critical values, while in deeper soil layers (35–80 cm), we found that penetration values on each tillage treatment begin to stabilize and smooth out in most cases, with similar dynamics on both soil types and measurement dates. In most of the cases, the highest PR was measured for conservation treatments in wetter soil conditions.

Spring barley (Hordeum vulgare L.) is an increasingly important cash crop in the province of Quebec (Canada). Soil–crop models are powerful tools for analyzing and supporting sustainable crop production. STICS model has not yet been tested for spring barley grown over several decades. This study was conducted to calibrate and evaluate the STICS model, without annual reinitialization, for predicting aboveground biomass and N nutrition attributes at harvest during 31 years of successive cropping of spring barley grown in soil (silty clay, Humic Gleysol) from the Saguenay–Lac-Saint-Jean region (northeastern Quebec, Canada). There is a good agreement between observed and predicted variables during the 31 successive barley cropping years. STICS predicted well biomass accumulation and plant N content with a low relative bias (|normalized mean error| = 0–13%) and small prediction error (normalized root mean square error = 6–25%). Overall, the STICS outputs reproduced the same trends as the field-observed data with various tillage systems and N sources. Predictions of crop attributes were more accurate in years with rainfall close to the long-term average. These 'newly calibrated' parameters in STICS for spring barley cropped under continental cold and humid climates require validation using independent observation datasets from other sites. [ABSTRACT FROM AUTHOR]

Soils with elevated arsenic contents are common in the Pannonian Basin. However, little is known about their distribution and occurrence. The subject of this study is the distribution of arsenic in Gleysol developed on an agricultural field in the Podravina region, Croatia. The main objective was to determine which soil parameter has the greatest influence on the overall distribution of arsenic in the area. Mineralogical, geochemical, and physico-chemical characteristics of 56 topsoil samples in were analyzed with statistical analyses, and the spatial distribution of the most important soil parameters was determined and presented. Mineralogical analysis revealed the presence of quartz, plagioclase, clays and micas, and Fe-oxyhydroxide goethite. Geochemical analysis determined elevated contents of iron (max. 23.37 mass. %) and arsenic (max. 824 mg/kg). The spatial distribution of eight parameters indicates overlap in the distribution of iron and arsenic, influenced by the topography of the area. The hierarchical cluster analysis resulted in two main groups: Fe-rich samples (Group 1) and Si-rich samples (Group 2). The Si-rich group of samples has lower arsenic contents, while the Fe-rich group has elevated arsenic contents. This indicates that iron content is the parameter that has the largest influence on the overall distribution of As. Although Fe-oxides can be dissolved under reductive conditions, the predominant presence of well-crystalized goethite implies that As is not mobilized under reductive conditions and remains adsorbed onto goethite mineral phase. [ABSTRACT FROM AUTHOR]

Microbial communities were studied in redoximorphic microsites of highly heterogeneous Gleysol at a mm scale using 16S and 18S amplicon sequencing to demonstrate if the composition of soil microbes reflects the differences in ferric and ferrous micro‐sites. In both explored gley horizons with redoximorphic features (Bg2 and Cg), ferric mottles were significantly enriched with total P and Fe and depleted of O, Si, Al, K and Ca compared with the adjacent ferrous groundmass (SEM–EDS). Ferric mottles were determined as Fe oxide coatings and hypocoatings. In Bg2, both prokaryotic and micro‐eukaryotic communities differed significantly between mottles and groundmass in composition of operational taxonomic units (OTUs) and in proportions of phyla, reflecting heterogeneities in the soil properties there. Mottles in Bg2 were characterized by increased proportion of Proteobacteria, decreased proportion of Acidobacteriota among prokaryotes and by dominance of a single proteobacterial OTU from Anaplasmataceae compared to all other samples. The composition of micro‐eukaryotes showed an opposite trend, as micro‐eukaryotes of Bg2 groundmass were unique among the other horizons, while micro‐eukaryotes of Bg2 mottles had similar composition to neighbouring horizons. Microbial communities of adjacent samples were not more similar to each other than communities of randomly selected ones in Bg2 horizon. That suggests that at mm scale, the sample distance does not represent the driving factor of microbial community composition and that the adjacent samples differ rather due to physicochemical factors. The spatial organization of microbial communities revealed in Bg2 has not reappeared in similarly organized Cg horizon, probably due to other overriding factors. The differences revealed between Bg2 and Cg horizons, including granulometric composition, content of crystalline Fe, exchangeable Al, and organic carbon, as well as exposition to groundwater, were discussed as possible reasons of the distinct organization in Cg. The similarity of pro−/eukaryotic communities of adjacent and non‐adjacent couples suggests no distance decay pattern at a mm scale. The agreement between patchiness in soil properties and microbial communities was revealed for the first time and confirms the importance of microscale patterns in soil. [ABSTRACT FROM AUTHOR]

Climate warming has significantly impacted the ecosystems of the Subarctic and Arctic. It has most strongly affected highly productive ecosystems, including those formed in river floodplains. Due to the initially high (background) values of NDVI, remote monitoring methods are not suitable for detecting changes in the biological productivity of floodplain vegetation. Research for both individual regions and landscapes is needed. However, for the floodplains of many rivers in Western Siberia, there are no primary descriptions of soils and vegetation. We have studied the soils and vegetation of the riverside floodplains in the lower reaches of the Taz River within the Pur–Taz interfluve. The studies were carried out within the hydrological continuum from the stream to the main Taz River. A regular change in soils and vegetation along the hydrological continuum was established, with fluvial processes intensifying. Ecosystems with the greatest diversity of plants, with thick layered soils such as Pantofluvic Fluvisol (Polyarenic, Polysiltic, Humic), are formed in the valleys of the tributaries of the Taz River on the natural riverside levee. The floodplain of the Taz River is distinguished by small differences in the heights of topographic elements, loamy soil texture, waterlogging and permafrost. The soils of the studied hydrological continuum were assigned to two Reference Soil Groups (Gleysol and Fluvisol). To describe the diversity of basic soil properties, six principal qualifiers and nine supplementary qualifiers were used. An assumption was made about the replacement of willow bushes by alder bushes during the warming period with the growth of some species of forbs (Parasenecio hastatus). The study made it possible to outline ways of further studying the floodplains of the Subarctic of Western Siberia.

Spring barley (Hordeum vulgare L.) is an increasingly important cash crop in the province of Quebec (Canada). Soil–crop models are powerful tools for analyzing and supporting sustainable crop production. STICS model has not yet been tested for spring barley grown over several decades. This study was conducted to calibrate and evaluate the STICS model, without annual reinitialization, for predicting aboveground biomass and N nutrition attributes at harvest during 31 years of successive cropping of spring barley grown in soil (silty clay, Humic Gleysol) from the Saguenay–Lac-Saint-Jean region (northeastern Quebec, Canada). There is a good agreement between observed and predicted variables during the 31 successive barley cropping years. STICS predicted well biomass accumulation and plant N content with a low relative bias (|normalized mean error| = 0–13%) and small prediction error (normalized root mean square error = 6–25%). Overall, the STICS outputs reproduced the same trends as the field-observed data with various tillage systems and N sources. Predictions of crop attributes were more accurate in years with rainfall close to the long-term average. These ‘newly calibrated’ parameters in STICS for spring barley cropped under continental cold and humid climates require validation using independent observation datasets from other sites.

Abstract To evaluate the sustainability of biomass plantations, effects on soil organic carbon (SOC) need to be quantified. Miscanthus × giganteus is increasingly used as a bioenergy plant, and it has been hypothesized that, after conversion from cropland, Miscanthus cropping increases SOC storage, whereas conversion from grassland to Miscanthus provides, on average, no sequestration. All field studies hitherto were carried out on mineral soils with topsoil SOC contents of below 3.3%. Here, we analyze in the temperate zone of Switzerland five sites that have been cultivated with Miscanthus for 19–24 years and of which four sites are higher in topsoil SOC content (4.7%–16.2%) and storage (188–262 t SOC) than any previously studied Miscanthus plantation in Europe. We used the difference in carbon isotopic signature between C4 (Miscanthus) and neighboring plots with C3 vegetation (grassland) to quantify the accumulation of new SOC from Miscanthus down to 0.75 m. Annual C4‐C accumulation rates were 1.66 (standard error ± 0.14) t C4‐C ha−1 year−1 (range: 1.26–2.01) in the upper 0.3 m of soil and 1.96 (±0.18) t C4‐C ha−1 year−1 (1.40–2.38) in 0–0.75 m. Average rates for 0–0.3 m were higher than those of mineral soils (n = 37) published previously (0.96 [±0.10] t C4‐C ha−1 year−1). However, high rates of C4‐C accumulation were also reported previously for some mineral soils. Nevertheless, the one mineral soil in our study did not reveal a systematically different accumulation of Miscanthus‐derived carbon compared with the four carbon‐rich soils. We therefore conclude that soils rich in organic matter do not show a different C4‐C accumulation pattern as compared with mineral soils. However, their C4‐C accumulation rates are at the upper end of the data ensemble. Our results further underpin that conversion to Miscanthus, despite C4‐C accumulation, provides no means to increase soil carbon stocks relative to grassland management.

Improvement of carbon sequestration in soils for a more sustainable environment and prevention of climate change require not only knowledge about soil organic carbon (SOC) stocks, but also about interactions between land use and total amount and distribution of carbon. In North Germany (state: Schleswig-Holstein) about 925 soil profiles in the four dominant geological regions [Weichselian glacial region, the sandy outwash region (Lower ―Geest), the Saalian glacial region Higher ―Geest), and the marshland with alluvial deposits] were sampled down to at least the 90 cm depth. Carbon content, pH, bulk density, and grain size distribution were analyzed for the major characteristic soil horizons. The four dominant geological regions possess different SOC stocks as well as SOC contents. The total amount of SOC stored within the representative soil profiles down to the 90 cm depth was analyzed for three depths: 0 – 30, 30 – 60, 60 – 90 cm; for the total area of Schleswig Holstein (15.369 km²), they summed to 244 Mt. SOC stocks, however, differed depending on the land use management system and clay content. Arable soils were most sensitive to soil deformation and the higher the clay content the less rigid they were, if the SOC to clay ratio were used as an index for structural quality. Grassland topsoils showed the highest SOC stocks and a mediate structural quality. The latter was highest for forest soils, which, however, had a higher SOC content but, at the same time, a less fertile SOC composition (litter with high C: N ratio). Further research on the carbon composition (labile, active, intermediate, or passive pools) would help to get a better insight into the role of SOC on soil strength and soil functions.

To evaluate the sustainability of biomass plantations, effects on soil organic carbon (SOC) need to be quantified. Miscanthus × giganteus is increasingly used as a bioenergy plant, and it has been hypothesized that, after conversion from cropland, Miscanthus cropping increases SOC storage, whereas conversion from grassland to Miscanthus provides, on average, no sequestration. All field studies hitherto were carried out on mineral soils with topsoil SOC contents of below 3.3%. Here, we analyze in the temperate zone of Switzerland five sites that have been cultivated with Miscanthus for 19–24 years and of which four sites are higher in topsoil SOC content (4.7%–16.2%) and storage (188–262 t SOC) than any previously studied Miscanthus plantation in Europe. We used the difference in carbon isotopic signature between C4 (Miscanthus) and neighboring plots with C3 vegetation (grassland) to quantify the accumulation of new SOC from Miscanthus down to 0.75 m. Annual C4‐C accumulation rates were 1.66 (standard error ± 0.14) t C4‐C ha−1 year−1 (range: 1.26–2.01) in the upper 0.3 m of soil and 1.96 (±0.18) t C4‐C ha−1 year−1 (1.40–2.38) in 0–0.75 m. Average rates for 0–0.3 m were higher than those of mineral soils (n = 37) published previously (0.96 [±0.10] t C4‐C ha−1 year−1). However, high rates of C4‐C accumulation were also reported previously for some mineral soils. Nevertheless, the one mineral soil in our study did not reveal a systematically different accumulation of Miscanthus‐derived carbon compared with the four carbon‐rich soils. We therefore conclude that soils rich in organic matter do not show a different C4‐C accumulation pattern as compared with mineral soils. However, their C4‐C accumulation rates are at the upper end of the data ensemble. Our results further underpin that conversion to Miscanthus, despite C4‐C accumulation, provides no means to increase soil carbon stocks relative to grassland management. [ABSTRACT FROM AUTHOR]

Background: Limited information is available on the changes in surface electrochemical properties of different‐sized particles of an Anthrosol, compared with the corresponding parental upland soil. Aims: Our overarching goal was to clarify the contribution of different‐sized particles to the soil surface charge. The specific objectives of this work were to examine the differences in the surface charge properties between the Anthrosol and its upland parental Gleysol and to reveal the properties of the different‐sized fractions separated from the Anthrosol, compared with those of the upland Gleysol. Materials and methods: The properties (e.g., negative surface charge, zeta potential, and particle sedimentation) of different‐sized fractions of nanoparticle (NP), coarse colloid, silt, and sand fractions separated from an upland Gleysol and its derived Anthrosol were compared. Results: NPs in both the Anthrosol and the Gleysol carried more negative charge than did the coarse colloids, with cation exchange capacities (CEC) being 186.5% and 58.8% greater, respectively. On the other hand, the presence of more positively charged Fe/Al (hydr)oxides compensated for the negative charge, resulted in a zeta potential of the NPs similar to that of the coarse colloids. More secondary minerals were observed in the coarse colloids of the Anthrosol than in the same fraction of the Gleysol, resulting in more negative charge on the surface of the Anthrosol coarse colloids. The coarse colloid fraction of the Anthrosol, therefore, had a greater CEC, despite representing a smaller mass fraction than in the Gleysol. Overall, the CEC of the Anthrosol was 21% lower than that of the parent Gleysol, which was consistent with the findings of the surface charge, using the cesium (Cs+)‐adsorption method. The sedimentation observations demonstrated that the suspension stability of the NPs was higher than that of the coarse colloids, and that they tended to disperse particularly under high pH conditions. Conclusions: Although the surface charge potential of the Anthrosol was lower than that of the upland Gleysol, the accumulation of organic matter and formation of secondary phyllosilicates resulted in maintenance of the nutrient‐ and pollutant‐binding capacity and agricultural productivity of the Anthrosol. [ABSTRACT FROM AUTHOR]

This work aims to contribute to the interpretation of soil colors; mainly to identify the pigments that generate the greenish colors in hydromorphic conditions (gley colors) in vertisols of the coastal plain of the Río de la Plata estuary. These colors are of cold hues, generally greenish (olive-gray), and occur in poorly drained soils with prolonged water accumulation. For this purpose, samples of Bssg horizons of hydromorphic vertisols from the coastal plain of the Río de la Plata estuary were analyzed using routine and chemical analyses, Mössbauer spectroscopy, determination of rocks magnetic parameters, X-ray diffraction, thermogravimetric and differential thermal analysis and petrographic-electronic microscopy. The pigments associated with the gley colors of these soils are mainly due to ferric iron content, corresponding to minerals such as ferric iron-rich smectites (nontronite/Fe-rich beidellite) and oxy-hydroxides like goethite, which colors range from green to yellow. These minerals, combined with gray or black components, e.g., manganese compounds and/or organic matter, contribute to the generation of the usual gley colors in the analyzed soils of the Pampean plain. The obtained data allows us to state that it is a mistake to assing the olive color in hydromorphic soils to the presence of ferrous iron compounds, as it is traditionally done. The oxidizing condition of iron is dominant in all the analyzed samples, integrating the composition of ferric iron-rich clay minerals and oxy-hydroxides (goethite). [ABSTRACT FROM AUTHOR]

Background: Wetlands in Neotropics harbor high fungal diversity, including arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE). This study describes the interaction of plant roots with AMF and DSE in a freshwater wetland belonging to a hotspot of biodiversity. Hypothesis: Differential root colonization between arbuscular mycorrhizal and dark septate endophyte fungi is influenced by plant species and abiotic conditions in a freshwater wetland. Studied species: Plant species colonized by arbuscular mycorrhizal and dark septate endophyte fungi. Methods: Properties of soils and the water column, floristic composition, root colonization by AMF and DSE, and molecular identification of AMF inside roots were studied. Results: Soils were Gleysol and flooded during the rainy season. Most of identified plant species were herbaceous, with Cyperus articulatus and Mimosa pigra as the dominant species. Seven of 8 analyzed plant species exhibited differential co-colonization between AMF and DSE. Repeated sampling for one year under flooding/dry conditions demonstrated that C. articulatus and M. pigra were mainly associated with DSE and AMF, respectively. A positive correlation between dissolved O2 in the water column and fungal colonization was observed in C. articulatus. Glomerales and Archaeosporales were molecularly identified inside roots containing arbuscules of M. pigra. Conclusions: Findings highlight differential coexistence between AMF and DSE in plant roots; fungal colonization was influenced by flooding/dry conditions in a neotropical wetland; the community of AMF inside arbusculated roots of M. pigra includes at least four clades.

Coastal lowlands of northeastern Siberia are composed of the Pleistocene ice-rich organic-containing loamy sediments of the Ice Complex (yedoma) and products of their transformation in the Holocene. In the tundra zone, three major trends of modern pedogenesis depending on the geomorphic position and age of particular landforms have been identified. On the interfluves affected by thermokarst processes in the Holocene, somewhat elevated remains of the Late Pleistocene Ice Complex alternate with vast thermokarst depressions (alases) with lakes. Cryozems are developed in automorphic plain positions and on the upper parts of slopes. The profiles of these soils are strongly affected by cycles of frost boiling and cryoturbation; under their influence, specific suprapermafrost accumulative organomineral horizons are formed. Gleyzation predominates in the soils of the low- and middle-level Holocene terraces of alases. Peat accumulation is progressively developed in the bottoms of alas depressions. [ABSTRACT FROM AUTHOR]

Herbicide residues can potentially injure sensitive crops grown in rotation. Thus, the objective of this study was to evaluate the sensitivity of six replacement crops to mesotrione residues 1 yr after herbicide application. In field bioassay, mesotrione was applied at recommended (144 g ai ha-1), twofold (288 g ai ha-1), and fourfold (576 g ai ha-1) rates at two soil types (Gleysol and Fluvisol). In field and laboratory bioassays, mesotrione residual activity was followed for a 21-d period using various measurements of phytotoxicity. No visible injuries to mesotrione residues were observed on oat (Avena sativa L.), rapeseed (Brassica napus L.), soybean (Glycine max [L.] Merr.) and sunflower (Helianthus annuus L.) in the field bioassay. Although mesotrione residues were not detected by HPLC-UV/DAD analysis, field bioassays indicated their presence due to visible injuries on field pea (Pisum sativum L.) grown in Gleysol soil with twofold and fourfold herbicide treatments. In contrast to other test crop responses, sugar beet exhibited visible injuries in both soils, and consequently, was subjected to laboratory bioassay. With increasing mesotrione rates, the reductions in sugar beet (Beta vulgaris L. var. saccharifera Alef.) fresh weight and total carotenoids content ranged from 6.2% to 18.7% and from 4.1% to 19.4% in Gleysol, and from 1.1% to 7.7% and from 0% to 11.9% in Fluvisol, respectively. Since herbicide residues could not often be detected by instrumental analysis, the bioassays seem to be a reliable tool for crop safety assessment. [ABSTRACT FROM AUTHOR]

Pedogenesis on the terraces of lacustrine–alas depressions in the tundra zone of the Kolyma Lowland takes place on sediments that are different in genesis but have significantly similar composition and properties. Soil morphology and soil cover patterns on terraces and slopes of depressions reflect the main trends of the Holocene pedogenesis and the rearrangement of the environment. On the terraces of the upper and middle levels, as well as on the interfluves, the major pedogenic trend is cryozem formation. On the lower terraces and in the bottoms of lacustrine–alas depressions, gleyzation and peat formation are considered to be stable and progressing processes. Soil formation is affected by close permafrost table (<1 m); therefore, all soils are qualified for Cryosols. [ABSTRACT FROM AUTHOR]

Introduction: Plants and microorganisms have been used as bioindicators to evaluate the toxicity of hydrocarbons in soils. Objective: This study evaluates the toxicity of a chronically-contaminated Gleysol with several concentrations of weathered petroleum hydrocarbons (WPH), collected from La Venta, Tabasco (Mexico), on the growth of Clitoria ternatea and the phytoxicity attenuation due to inoculation of emulsifying bacteria. Methods: Soils with 50 and 150 g WPH kg-1, and control soil with 0.15 g WPH kg-1 (biogenic origin) were utilized, as well as the inoculation of six emulsifying bacteria and their combination (consortium). The WPH-phytotoxicity was evaluated by considering plant height, dry biomass production (root, shoot, and total), leaf area, specific leaf area, and the efficiency of photosystem II (EPSII), after 30 days. Results: WPH did not affect plant height, but soil with 50 g WPH kg-1 diminished root and total dry weight, and leaf area, when compared to both control soil and soil with 150 g WPH kg-1. The strain Sml (Stenotrophomonas maltophilia C10S1) significantly increased shoot and total dry weight, while the strain Ro (Raoultella ornithinolytica C5S3) produced higher specific leaf area relative to uninoculated plants. In control soil, the bacterial consortium stimulated plant height. The strains Sm (Serratia marcescens C11S1) and Sm2 (S. marcescens C7S3) improved plant height and specific leaf area when compared to uninoculated plants in soil with 50 g WPH kg-1. In soil with 150 g WPH kg-1, strains Spa (Stenotrophomonas pavanii C5S3F) and Cfr (Citrobacter freundii C4S3) enhanced root and shoot dry weight, respectively. The EPSII was unaffected by soil contamination. Emulsifying bacteria reduced the phytotoxic effects of WP, but depending on the content of WPH in soils. Conclusions: Soil with 50 g WPH kg-1 showed the greatest phytotoxic effects on plant growth. Bacterial inoculation favored growth, biomass production and leaf area in soil with 150 g WPH kg-1. The EPSII was not affected by WPH in soils. [ABSTRACT FROM AUTHOR]

In our study, by investigating reambulated soil profiles from the Nagy-Sárrét region in Hungary, we attempt to determine the extent of changes which have occurred due to effects which impacted the landscape in terms of the soil chemistry properties of soil profiles exposed during the Kreybig soil survey more than 70 years ago. Based on the results, in the areas used as grassland, we observed a decrease in pH and an increase in the humus content of the topsoil. The increased CaCO3 following the chemical improvement of the soil which was used as cropland is still characteristic of the area. During the past decades, the investigated soils have been affected by significant changes with regard to water management, which have also modified the investigated parameters. We have classified the reambulated soil profiles among the Solonetz, Vertisol, and Gleysol reference groups based on the World Reference Base of Soil Resources (WRB) diagnostic system.

The evaluation of soil properties allows to know the level of degradation of indicators related to fertility and to have a better understanding of the responses of crops to fertilizer applications, in order to obtain acceptable yields. The present work was carried out with the objective of characterizing the current state of two types of soils dedicated to the production of forage plants for cattle feed. In both soils, their contours were delimited, their profiles were morphologically described and later they were classified. In the agrochemical sampling, elementary plots were delimited by soil type, in which a sample was formed for each one, to which were determined the pH, the assimilable phosphorus, the interchangeable cations, the content and the carbon reserve and They took several samples to determine their mechanical composition, clay dispersion coefficient, natural and hygroscopic moisture, soil density and solid phase density, total porosity and stability of the aggregates. The soils studied were classified as Gley Nodular Ferruginous and Red Brown Fersialitic. In addition, both soil types showed signs of degradation in the upper horizon, reflected by a low carbon content, high dispersion coefficient of clay, low moisture retention, low percentages of porosity, high values in the density of the soil and the density of the solid phase, together with a structure characterized by the presence of medium-sized prismatic blocks. [ABSTRACT FROM AUTHOR]

Abstract Mound fields (MF), which consist of numerous isolated mounds, are characteristic of the Cerrado wetlands of Brazil. While there are numerous studies on soil redistribution by termites and by differential particulate erosion, a new hypothesis, supported by metal accumulation in these areas, needs to be tested. This study aimed to investigate the extent to which soil saturation by water, and the associated chemical erosion, might be a key driver of the geomorphological development of the Cerrado wetlands. The study was performed in a typical wetland of Minas Gerais that shows a typical succession from well drained Ferralsols on the plateau to Gleysols on the lowland and the presence of MF at the transition. Soil morphological description was used together with optical microscopy, X-ray fluorescence and physical analyses (grain size and bulk density) to discriminate between the biological (bioturbation) and geochemical origins. Additionally, geochemical mass balance was calculated to estimate the total amount of chemical erosion that had occurred in the area. The morphological observations and the results on soil texture did not point to material redistribution in the MF. In contrast, the results showed that iron-depleted aggregates in depressed zones were sensitive to collapse. Soil saturation by water as the main cause of geochemical erosion and geomorphologic development was confirmed by mass balance calculation. The results fill an important information gap on the formation and evolution of cerrado soil landscapes, which have important consequences for biodiversity and water conservation. Highlights • New insights into soil saturation by water and chemical erosion in tropical wetlands. • Iron-depleted aggregates are sensitive to collapse. • Soil subsidence and geomorphology in catchment are controlled by hydrology. [ABSTRACT FROM AUTHOR]

One of the most important premise to arise the suitablemanagement of soils in a region is the study of the distribution and characteristics of soils. For this reason, the main objective in this paper was to elaborate a soil map in scale 1:25 000 for the Carrizal-Chone System (7 233 ha) in Manabí, Ecuador. At the same time to know, the chemical, physical and morphological soil characteristics, based on 145 soil profiles that were taking in different soil separated in the map. Among the results is the diagnosis and classification of four Referential Soil Groups, Fluvisols (53% de of the total area), Feozems (29%), Cambisols (14%) and Gleysols (4% only), by the World Reference Base soil classification system. In this paper are included the study of Soil Units in each Referential Soil Group. Is determined that the natural soil formation in this region is Feozem and Fluvisol, the Cambisol appears because the degradation of the cambicFeozem for the cultivation during many years. In the results are present also, the analytical data of the Referential Soil Groups studied. [ABSTRACT FROM AUTHOR]

This paper presents a brief description of the soil cover in the Lighed, Lunca Timişului Forest Administration (Romania), and of the woody vegetation within the studied perimeter for sustainable use.(11) Together with the other elements of the environment (water, air, vegetation, and fauna), soil is the essential element that ensures food for both plants and humans and animals, participating in the different vital cycles of ecosystems; it is the cradle and source of existence for humankind. Hence the necessity of deeply knowing nature and soil features, its functions, its complex relationships with other components of the environment for sustainable use and soil reserve management, so that soil cover be free of damage that could impact the environment.(9)Studies were carried out within the production unit VII Lighed, part of the Lunca Timişului Forest Administration, Forest Office Timişoara - National Regie of Forests, where it covers 1657.3 ha in north-west. (4)This paper presents climate and edaphic ecological indicators differentiating forest stations from the perspective of their economic value. The permanent hydrographic network is made up of the Timiş River and Pogonici Rivulet. (6,10)The goal of the paper was to identify soils within this forest administration for proper, effective, and sustainable use. (7)Research was carried out in the field, laboratory, and office. The goals of the study were knowing the physical geographical landscape, determining ecologic and climatic indicators based on local Weather Stations, identifying natural vegetation depending on their yielding level (high, medium, and low), describing soils and station types, and making recommendations after establishing the economic value of each forest station. (3)Research in the field and in the laboratory allowed us to identify the following soil types and sub-types: chernic gleysol, gleysol, alluvial gley soil, and mollic alluvial gley soil.(2,5) [ABSTRACT FROM AUTHOR]

The Mexican tropical wetland is a coastal system with capacity to support the contamination derived from the extractive industry and the transformation of crude oil, due to its high plant biodiversity and the presence of rhizospheric reducing sulphate bacteria from plants tolerant to crude oil. A field experiment was carried out for nine months to evaluate the adaptation of aquatic plants Leersia hexandra grass and Eleocharis palustris spikerush reintroduced in a wetland contaminated with 75 560 to 118 789 mg kg-1 of weathered petroleum and also with sulfate, derived from oil and gas pipeline leaks, and gaseous emissions. The effect of the weathered oil and sulfate on the dry matter production and the population density of the bacterium Desulfovibrio spp, isolated from the rhizosphere and soil of both plants, were evaluated. The means of the variables had statistical differences (p< 0.05). Weathered oil inhibited dry matter production of L. hexandra but not E. palustris; the effect of petroleum on Desulfovibrio density was very significant negative in the rhizosphere and in the soil of both plants. Sulfate reduced the dry matter of grass. The exposure of Desulfovibrio to sulfate significantly reduced its density in rhizosphere and soil (p< 0.01). We recommend the use of E. palustris for the decontamination of flooded soils contaminated with weathered oil and sulfate. [ABSTRACT FROM AUTHOR]

The aim of this paper is to realize a description of forest soils from Arad County. The work material is represented by soil analysis data from forest management plans made in the period 1985-2015 from 22 forest districts, meaning 483 soil profiles and 1332 pedo-genetical horizons. The soils found in Arad are characteristic to the area of low hills (luvisols, preluvisols, eutric cambisols). However, field soils (phaeozems), mountain soils (dystric cambisols) and even azonal soils (fluvisols, gleysols) are present, in the order of their spreading: luvisol (moderately acid, mezobazic in Ao and Bt and oligomezobasic in El, with a high total cationic exchange capacity, well supplied with nitrogen and intensely humiferous), eutric cambisol (moderately acid, mezobazic, with a high total cationic exchange capacity, very well supplied with nitrogen and intensely humifeous), preluvisol (moderately acid, mezobazic, with a high total cationic exchange capacity, very well supplied with nitrogen and intensely humiferous), gleysol (eubazic, with a very high total cationic exchange capacity, very well supplied with nitrogen and moderately humiferous). [ABSTRACT FROM AUTHOR]

Recent flooding of agricultural land in the northern Prairie Pothole Region – coupled with intensification of agriculture – has resulted in renewed efforts to drain Prairie Potholes. Drainage is used to improve growing conditions and increase the amount of land that can be cultivated. The aim of this study was to determine if duration of agricultural drainage improved growing conditions and nutrient availability, by measuring physical (i.e. structure and bulk density) and chemical properties (i.e. C, N, and P). Forty-two wetlands and paired midslopes were selected in the Prairie Pothole Region in the Black soil zone of southeastern Saskatchewan. Drainage duration of wetlands ranged from 0 to 50 years. Results suggest drainage does improve growing conditions and nutrient availability for agricultural production, but these changes vary across wetlands drained for different durations of time. Compared with undrained soils, changes were greatest in soils drained from 20 to 34 years, but decreased after 36 years becoming more similar to cultivated midslope positions. Some drainage benefits include increased nitrification and greater available PO 4 −3 at a depth of 0–15 cm. Phosphorus sorption decreased with drainage duration and P desorption increased in soils drained from 7 to 34 years. This could result in greater available N and P for crop uptake, but could also lead to greater nutrient losses. Additionally, bulk density increased and microaggregates decreased with drainage duration. Compared with undrained soils, drainage did not have a significant effect on macroaggregates, soil organic carbon, water extractable organic carbon, light fraction, total N, NO 3 − , and mineralization. It is likely other agricultural practices used in conjunction with drainage, such as tillage, fertilizer additions, and crop removal, are affecting how these soil properties change over time. The resulting quantitative data from this study provides an excellent resource for planning management strategies to improve nutrient use efficiency and reduce losses to the environment. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of crude oil on the intraradical structures and morphospecies of arbuscular mycorrhizal fungi (AMF) and on the aerial and root dry matter of the grass Leersia hexandra Swartz in order to propose indicators of toxicity. An experiment was conducted in a microtunnel for 180 days. The concentrations (g kg) of crude oil in the Gleysol were 0.693 (control), 3, 10, 30, 60, 90, 120, 150, and 180. The growth of intraradical hyphae, arbuscules, vesicles, and spores in soil was stimulated by crude oil concentrations of 3, 10, 30 and 60 g, but concentrations of 90, 120, 150, and 180 g kg inhibited it. Eight morphospecies of AMF were identified. The number of spores of Rhizophagus fasciculatus, Rhizophagus intraradices, Funneliformis geosporum, Diversispora eburnea, and Ambispora gerdemannii showed sensitivity to the concentration of crude oil (index values were lower than one). The number of spores of Diversispora sp. was stimulated by exposure to crude oil, with non-toxic values for the eight concentrations. The index based on the aerial dry matter of L. hexandra showed toxicity values lower than one with crude oil concentrations of 60, 90, 120, 150, and 180 g kg, but the root dry matter showed non-toxic values with the eight concentrations. We suggest using the number of spores and morphospecies as an index of toxicity of crude oil and recommend using Diversispora sp. and L. hexandra for the phytoremediation of Gleysol contaminated with crude oil in the Mexican humid tropics. [ABSTRACT FROM AUTHOR]

In wetland soils, the mobility of geogenic metal(loid)s is usually associated with direct or indirect microbial-induced processes (solubilisation of mineral and organic components, pH induced desorption, competition effects, dissimilatory reduction). To identify the role of microbial reducing activity in As and Sb release, we conducted two series of soil incubations (sodium azide-treated (NaN3-T) and non-treated (NT)) in closed batches for 36 days. During the incubation period, we monitored the evolution of dissolved As, Sb, Mn, FeII, organic carbon (DOC), humic substances (HS) and proteins (PN) with their apparent molecular weight distribution (aMW) as well as pH, reduction potential (Eh) and alkalinity. Results showed that the release of As and Sb occurred when microbially reducing conditions prevailed (NT soil Eh ~0 mV and FeII > 40 mg L-1) and was inhibited for As in the absence of microbial reducing activity (NaN3-T soil; Eh > 250 mV and Fe < 1 mg L-1). In contrast, Sb behaved differently since its release was only slowed down when microbially reducing conditions were inhibited. We concluded that soil microbial reducing activity fully controls the release of As and to a lesser extent that of Sb when NaN3 is used as a microbial inhibiting agent. Since Sb release and dissolved organic matter (DOM) solubilisation (NaN3-induced artefact) occurred simultaneously in the absence of microbially reducing conditions, we concluded that organic matter could be one key factor controlling Sb mobilisation in the given conditions, which is not the case for As. [ABSTRACT FROM AUTHOR]