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Purpose Tailings are generally characterized by severe physicochemical conditions that limit the establishment of vegetation. The present study aimed to select suitable combinations of organo-mineral amendments to improve the physicochemical, biochemical, and biological properties of spolic technosols, highly contaminated with metals. Materials and methods Several substrates were prepared by mixing mine tailings (MT) of an abandoned mining area with non-contaminated agricultural soil (anthrosol), green waste compost, lime, and rock phosphate at different rates: S1 - 50% of MT + 50% of agricultural soil; S2 - S1 + 3% of lime (CaCO3); S3 - S1 + 6% of rock phosphate; S4 - S1 + 10% of compost; S5 - S1 + 10% of compost + 3% of lime; S6 - S1 + 10% of compost + 6% of rock phosphate. Untreated MT and agricultural soil were analyzed immediately, and 8 months after incorporating the amendments. Results and discussion Heterotrophic microorganisms were not recovered from untreated MT due to the highly acidic pH and available metal concentrations. However, the addition of organo-mineral amendments ameliorated the tailings' characteristics by increasing pH, conductivity, total organic carbon, and available P levels. Moreover, after 8 months, heterotrophic microorganisms were recovered from those substrates and dehydrogenase activity was enhanced. The incorporation of agricultural soil and green waste compost mixed either with lime (S5) or rock phosphate (S6) was the most effective treatment. Conclusions Both S5 and S6 mixtures successfully reduced the environmental risk posed by tailings, suggesting the potential use of these amendments for the remediation of pyrite mines.

Phosphorus (P) and silicon (Si) mobility and their interactions in soils are sensitive to soil pH. Although Si fertilizer application has been reported to efficiently increase P availability in soils, the responses of Si mobility and availability to soil P enrichment are not well understood. This study investigated the effects of P addition and artificial soil acidification on Si sorption and availability in a Hydragric Anthrosol using adsorption, soil incubation, and rice growth pot experiments. When Si and P were simultaneously added at equimolar concentrations between pH 3.5 and 6.5, the presence of P decreased Si adsorption by 22–88% at the corresponding pH, suggesting that P had a greater affinity to soil solids than did Si. Si sorption by the soil generally increased with pH increasing in the pH range of our study, and the reduction of Si sorption due to P addition was more significant under higher pH conditions (e.g., CK (soil without pH adjustment, pH = 6.4) and pH 5.5 treatments). Soil acidification and P addition that decreased Si sorption resulted in greater Si mobility and availability, as indicated by higher soil CaCl2-extractable Si content and greater Si uptake and Si content of rice plant. Our results highlight the importance of Si mobility or loss due to P enrichment and soil acidification in weathered soils used for Si-accumulating plants such as rice.

Elevated concentrations of total mercury (THg) are found in the surface soils and flanking wetland sediments at the Classic Maya coastal site of Marco Gonzalez, Belize. Significant concentrations (up to 1.3 µg·g−1 dry mass) of THg occur in leaf litter-rich soils, as well as in the artefact-rich anthrosol spread over the vegetated mound site of structures and occupation debris. The abundance and spatial pattern of major and trace elements measured in the surface soils indicate both site-scale controlling factors of topography, structures and vegetation on soil geochemistry as well as local highs in concentration compared with background, due to human activity. Geochemical stratigraphy of wetland sediment cores shows that a shift from carbonate-reef sediments to mangrove peat in the 13th century AD was attended by an input of allogenic (mineral) elements, including mercury. A THg concentration peak (0.8 μg·g−1) in brackish pool sediment is 210Pb-dated to 1960–1970 AD, but the incorporation of mercury in multiple cores adjacent to the site shows increasing mercury inputs to have occurred before, during Classic-period Maya occupation and following the sites abandonment. Analysis of element values from site-scale soil sampling, combined with results from off-site cores, provides a numerical framework upon which outlier values of THg and other element spatial patterns can be assessed, especially the spatial co-association of elements related to differences in soil–sediment matrices. Geochemical results from active soils developing from occupation deposits (anthrosols) and sediment cores open up questions concerning contemporary and past mercury accumulation at coastal Mayan sites, and the wider interaction of human and natural biogeochemical processes that occur in human-modified soils and coastal wetland sediments.

Special Issue: South America., The Atacama Desert is among the driest places on Earth, yet ancient agricultural systems are present in the region. Here, we present a study of terraced agricultural soils in the high-altitude eastern margin of the Atacama Desert in northern Chile, mainly dating to the Late Intermediate Period (ca. 950–1400 AD) and Inka period (ca. 1400–1536 AD). Terraced fields were compartmentalized to distribute limited irrigation water originating mainly from springs. Natural soils used for agriculture are mostly Aridisols developed on Pleistocene alluvial fan terraces and hillslopes underlain by volcanic bedrock. One research objective is to evaluate long-term soil change from agriculture. In this hyperarid climate, agriculture is only possible with irrigation, so natural soils on the same geomorphic surface adjacent to irrigated soils provide baseline data for assessing anthropogenic soil change. Data from soil profiles and surface transects indicate intentional soil change through terracing, removal of soil rock fragments, and probable fertilization. Agricultural soils have anthropogenic horizons ranging from 16 to 54 cm thick. Most agricultural soils have higher phosphorus levels, suggesting enrichment from fertilization. Changes in soil organic carbon and nitrogen are also evident. Unintentional anthropogenic soil change resulted from CaCO3 input through irrigation with calcareous spring water. Initial studies suggest that agriculture here was sustainable in the sense of conserving soils, and maintaining and possibly improving soil productivity over centuries., This study was supported by the Comisión Nacional de Investigación Científica y Tecnológica de Chile (CONICYT-USA 2013-0012), National Science Foundation (Catalyzing International Collaborations Grant, Award OISE-1265816), National Geographic Society (Grant #9296-13), the Wenner Gren Foundation for Anthropological Research, the University of New Mexico Latin American and Iberian Institute, the Spanish Ministry of Culture (Actuaciones Arqueológicas en el Exterior), the Spanish Ministry of Science and Innovation (HAR2017-87951-R, AEI/FEDER, UE), and the School for Advanced Research (Research Team Seminar).

Background: In search for more sustainable crop production, the subsoil has recently come into focus as considerable reservoir of nutrients and water. Aims: Dimensions of subsoil phosphorus (P) reserves are yet largely unknown but crucial for identifying regions suitable to include subsoil into sustainable management strategies. Methods: We analyzed stocks of total and plant-available (calcium acetate lactate-extractable) P in 96 representative soil profiles of German arable land down to 1 m depth. Results: We found that the German arable soils stored, on average, 8 t ha–1 of total P, of which nearly 500 kg ha–1 were readily plant-available. Notably, one third of plant-available P was located below the plow layer and one fifth even at depths below 0.5 m. The depth gradients of plant-available P stocks were affected more by major reference soil group than by texture. Generally, Chernozem but also Anthrosol, Gleysol and Fluvisol exhibited the largest P stocks in German cropland. The contribution of plant-available P to total P stocks was larger in sandy and extremely acidic (pH < 4.5) soils compared with more fine-grained and slightly acidic to alkaline soils, possibly because fertilization compensated for overall lower total P stocks at these sites. Generally, the more P was stored in topsoils, the more P was stored also in subsoils. Conclusions: A hypothetical crop utilization of 10% from plant-available P stocks and 0.1% from total P stocks from shallow subsoil could compensate for P fertilization by ca. 8 kg ha–1, but the rate of plant-available P replenishment in subsoil likely remains the crucial factor for the role of subsoil P stocks in crop nutrition. Generally, the large P reserves found in subsoil could act as an ‘insurance’ system for crops.

Although amending biochar into agricultural soils has been regarded as an effective measure to improve crop productivity, it remains unclear why biochar increases crop yield. The objective of this study was to compare the relative contribution of different biochar components in crop growth promotion. Three biochar components were separated: (i) water-soluble biochar extract (BE), (ii) mineral nutrients from biochar ash (BA), and (iii) washed biochar residue (WB). Two soils (Anthrosol and Primosol) with distinctly different organic carbon content, soil texture and land use were amended with the three biochar components and their effects on maize (Zea mays L.) growth were tested in a pot experiment. We hypothesized that (1) plant grown in the Anthrosol benefitted more from the water-soluble compounds of biochar than from its mineral nutrients or washed residue, since the soil is already fertile and has a good structure; (2) plant grown in the Primosol benefitted more from the mineral nutrients of biochar and its washed residual, since the soil is nutrient-poor and has a poor structure. The addition of biochar and its three components increased maize aboveground biomass for both soils. In the Anthrosol, BE, BA, and WB increased the aboveground biomass by 41.6%, 32.7%, and 27.1%; in the Primosol, they increased the aboveground biomass by 41.3%, 24.4%, and 18.2%, respectively. BE had the highest plant growth-promoting effect compared to the other two biochar components, which was regardless of soil condition. In addition, the biomass, total volume, surface area, and number of maize root tips under BE amendment were significantly enhanced, particularly the fine roots (

Archaeological Dark Earth soil is a category of archaeological anthrosols that has gained much attention because it exhibits higher nutrient content and organic matter stocks and a characteristic dark colour, and enables higher crop yields in comparison to neighbouring soil. However, much is unknown about the chemical properties of Archaeological Dark Earth soils in Central Europe. Therefore, we studied a European Dark Earth (EDE) soil, a type of Archaeological Dark Earth soil, in the territory of the early medieval Dřevic hillfort, Czech Republic, aiming to compare the chemical properties of EDE with a control soil unaffected by settlement activities. The black colour of EDE soil contrasted highly with the light grey Cambisol of the control. Soil reaction and total element contents (N, P, Ca, Mn, Fe, Al, Cu, Zn, Sr and Rb) were substantially larger in the EDE soil compared with the control and vice versa in the case of the C/N ratio. Also, the content of plant‐available (Mehlich III) P, Ca, K and Mg was larger in the EDE soil than the control. In contrast to Ca, plant‐available and total P and K were not well correlated. Total element contents are highly suitable for geoarchaeological purposes as enrichment factors can be easily calculated. The increased contents of these elements, together with pieces of charcoal visible in the EDE soil, indicate the deposition of organic waste and biomass ash during the existence of the hillfort. Thus, medieval hillforts can represent extraordinary nutrient‐rich islands in the cultural landscape of Central Europe. The chemical signatures generated by past settlement activities are so intense that they cannot easily be masked by short‐term intensive application of mineral fertilizers. HIGHLIGHTS: Settlement activities increased soil pH and the content of anthropogenic elements. Enrichment by P, Ca, Mn, Fe, Al, Zn, Cu, Sr and Rb may indicate settlement activities. Analysis of total element contents is suitable for geoarchaeological purposes. Application of mineral fertilizers cannot easily mask signatures of medieval settlement activities.

Soils of Bykovo lacustrine-like floodplain section have a complicated landuse history: alternation of meadows, suburban farming, cropland with partial land leveling and local drainage, now – 10 years-old layland. The effects of these events along with manifestations of fluvial pedogenesis were studied in thin sections. Well-known micromorphological features of alluvial soils have been confirmed, specific properties related to the position of soils in lacustrine-alluvial landscape have been revealed. Fluvial fabric elements are rather mitigated, since flooding of this section was weak and irregular; topsoils are similar in natural and post-arable soils and have no traces of agrogenic degradation. The layland regime contributes to soil regradation: higher pedality and pedofauna activity were recorded. Artificial drainage is recognized in thin sections by changes in iron (hydr)oxide pedofeatures vs. the natural gley soils, namely, iron segregations and nodules in the former soils (Fluvic Mollic Gleysols), and iron coatings, zones of complete bleaching alternating with strong impregnations in the latter. Soil on the terrace outlier was identified as a truncated texturally differentiated soil, which upper part was removed during leveling, then a new layer was placed on BT (argic) horizon: (Terric Anthrosol (Loamic, Gleyic, over buried Retisol)). Filled layers may contain blocky subangular peds of BT horizon, partially assimilated in the soil mass. These peds serve as micromorphological markers for reconstructing soil history owing to their easily recognizable particular properties: blocky subangular microstructure, speckled b-fabric, clay (hypo)coatings.

In recent years, rice crop intensification, which has put a lot of pressure and led to a great change in soil resources and its distribution. In Haugiang province of Vietnam, under different land uses, the previous soil map (2008) has changed and out of date. The research aims to update the soil map of the province under different land uses. The collection of 175 soil profile description data, and 51 soil analysis profiles. Soil classification was followed WRB 2006. The results showed that two major soil groups were found, in which four diagnostic horizons (Mollic, Umbric, Plinthic, and Sulfuric); one diagnostic property (Gleyic); and one diagnostic material (Sulfidic) were identified, and 15 soil types were classified. The Gleysols soil group have 14 soil types (hamoGL, hamoGL(hu), monplGL), (moGL(ptip), moGL(ntip), moGL(dtip), (umGL(ptio), huGL(ptio), umpplGL(ntio), umGL(ntio), huGL(ntio), umGL(dtio), (mowsGL(ntip), umwsGL(ntio)) total area of 9,551.32 ha, accounting for 59.34%; while Anthrosols soil group have one soil type (RGah) area of 66,252.91 ha, accounting for 40.66%. Soil map of the province was updated according to WRB 2006, which pineapple, sugarcane crops have a high tolerance of acidity and fruit crops are mainly on Anthrosol soil group, where acid sulfate soils, low in soil pH and base saturation, are dominated. While rice cultivation is dominated on most of Gleysols soil groups, including alluvial and acid sulfate soils. The acid sulfate soils of the study area have low pH, high acidity, high Al content, and low base saturation, in which crops need high tolerance of low pH such as pineapple, sugarcane, fruit crops, but most of the crops should grow on a raised bed for easy to leach soil acidity and toxicity.

The agricultural use of manure fertilizer increases the phosphorus (P) saturation of soils and the risk of colloidal P (Pcoll) release to aquatic ecosystems. Two experiments were conducted to identify whether Pteris vittata plantation can decrease Pcoll contents in two soils (Cambisol and Anthrosol) amended with various manure P rates (0, 10, 25, and 50 mg P kg−1 of soil). The total Pcoll contents in manured soil without P. vittata were 1.14–3.37 mg kg−1 (Cambisol), and 0.01–2.83 mg kg−1 (Anthrosol) across manure-P rates. The corresponding values with P. vittata were 0.97–2.33 mg kg−1 (Cambisol) and 0.005–1.6 mg kg−1 (Anthrosol). Experimentally determined colloidal minerals (Fe, Al, Ca), colloidal total organic carbon, Mehlich−3 nutrients (Fe, Al, and Ca), and the degree of P saturation were good predictors of Pcoll concentrations in both soils with and without P. vittata plantation. In unplanted soils, P adsorption decreased and the degree of P saturation increased which released more Pcoll. However, P. vittata plantation decreased the Pcoll release and P loss risk due to the increase of P adsorption and reduced DPS in both soils. The P fractions (NaOH, NH4F, and HCl–P) contributed to increase the P pool in planted soils which enhanced the bioavailability of Pcoll and increased the P. vittata biomass. It suggested that P. vittata plantation was an effective approach to reduce Pcoll release from manure amended soils.

Nitrogen (N) fertilizer placement in bands is a widely accepted agricultural practice to increase N use efficiency. An excessive ammonium concentration in a fertilizer band can increase osmotic stress on ammonia oxidizers and potentially affect nitrification and resultant nitrous oxide (N2O) emissions, which is of great significance for soil function and climate change. The objectivity of this study was to identify the effects of excessive ammonium concentration on N2O emissions and ammonia oxidizers in two agricultural soils. In this study, we established a 56-day soil microcosm receiving a series of high concentrations of urea at 600, 900, and 1200 mg N kg−1 (termed as N600, N900, and N1200, respectively), which simulated high ammonium levels in the center or proximity of a fertilizer band in two types of agricultural soils (fluvo-aquic soil and anthrosol). The mineral N concentrations, net nitrification rate, and N2O emissions were measured during the incubation. In addition, the abundances of bacterial and archaeal amoA were determined by using real-time quantitative PCR. Urea fertilization simultaneously increased the net nitrification rate and N2O emission at the early stage of incubation in both soils, suggesting N2O production was mainly from ammonia oxidation. Ammonia oxidizing bacteria (AOB) but not archaea (AOA) abundance was stimulated following urea fertilization and was positively correlated with N2O emission, indicating the dominant role of AOB in ammonia oxidation and N2O production in fertilized soils. The cumulative N2O emission was significantly higher in N1200 and N900 than N600 in both soils, but no further increase was observed in N1200 in the anthrosol. This implies restricted N2O production of ammonia oxidizers at excessive ammonium concentrations in the anthrosol. In the two soils treated with no N addition, the abundances of AOA amoA increased along the incubation time. The present study collectively suggested that excessive urea-N addition was more effective in inhibiting N2O emission in the anthrosol than in the fluvo-aquci soil. AOB rather than AOA dominated the soil nitrification and N2O emissions under high N addition in both soils. The band fertilization regime may reduce the loss of N fertilizer from nitrification without necessarily increasing N2O emissions.

Background Long-term drastic anthropic inputs in conventional monoculture systems cause negative plant-soil feedback that will largely affect sustainable cucumber cultivation. The inclusion of multicropping in intensive cropping systems could reduce the detrimental effects of continuous cropping obstacles. The present study investigated the dynamics of soil microbial communities, soil enzyme activities and cucumber yield under plastic tunnel cultivation for three successive growing seasons (2013, 2014 and 2015). Result In the amended crop rotation system, soil pH decreased with increasing number of cropped garlic bulbs. The soil electrical conductivity significantly changed during the entire growth period and increased with increasing number of incorporated garlic bulbs. The level of soil organic matter content increased in the last year (2015). Soil catalase activity was generally induced by the treatments of 10, 15, 20 and 25 garlic bulbs, and soil invertase activity was also enhanced by all the treatments in the last year. Similarly, fungal species richness dramatically increased under these crop rotation systems. In this study, we found the highest cucumber yield under the cropping treatment of 20 garlic bulbs. Conclusion The results indicate that the green garlic/cucumber cropping system is a sustainable and efficient cropping system for cucumber production and can improve the soil environment to a certain extent. © 2019 Society of Chemical Industry.

As soil ecosystem engineers, ants considerably affect soil physical and chemical properties, and further accordingly affect soil erosion. However, few study was made on studying the effects of ant-burrowing activities on soil erosion previously. This study quantified the impacts of ant (Camponotus japonicus)-burrowing activities on runoff and soil erosion rates. Simulated laboratory rainfall experiments were undertaken on six soil tanks filled with clay-loam soil classified as a cumulic anthrosol, three of which introduced with ant colonies for two days and the other three were without ant colonies, under 40, 80, and 120 mm h−1 of rainfall intensities and a slope of 15°. Results showed that ants made mounds with a bulk density of 0.75 g cm−3, which was lower than that of the soil matrix, i.e. 1.34 g cm−3. Soil erosion rates for the tanks with ants were 6.78, 36.90, and 62.00 g m−2 min−1 under three rainfall intensities of 40, 80, and 120 mm h−1, which were much higher than those of 3.94, 23.49, and 44.48 g m−2 min−1 for the tanks without ants. Ant nests reduced the runoff rate by 31%, 20% and 13% compared with those without ants and enhanced the soil water storage within 90 cm depth. Ant nests played a positive role in soil water conservation due to the large nest entrance diameter and the continuous macropore network. However, the ant mounds provided a loose erodible material and changed micro-topography of the slope surface, thereby accelerating the rill formation and exacerbating soil erosion. This study can help understand the effects of burrowing insects on soil erosion, which is an important environmental problem on the Loess Plateau.

We tested an efficient, easily and economically manufactured wind-transported particle collector of our own design, called a multidirectional trap (MDt), on fine-tilled Anthrosols. Results from the logs of nine vaned masts, each with four MDt collectors at different heights, showed a clear predominance of northeast and south winds. After analyzing sediment transport rates and their balance, we found that sediments from the south were being deposited rather than lost. A large amount of phyllosilicates, which are highly adhesive sediments, and therefore, increase aggregation, decreasing erodibility, were captured in the upper traps. Moreover, they are rich in calcium carbonate, mainly calcite, which is a powerful aggregate, and therefore, also decreases their wind erodibility. Sediments from the northeast, however, with almost double the total mass transport, contained the largest amount of captured quartz, promoting abrasion and increasing soil erodibility. Nevertheless, large amounts of organic matter found in sediments from the NE led to some aggregation, which balances material lost.

Biochar has shown beneficial effects in agricultural production, yet the combined effects of biochar and reduced irrigation on crop growth and water-use efficiency (WUE) in diverse soil types have not been fully explored. A split-root pot experiment was conducted to investigate the effects of addition of 2% softwood (SWB) and wheat straw biochar (WSB) on growth, physiology, WUE and nutrients uptake of tobacco (Nicotiana tabacum L.) plants grown in a Ferrosol and an Anthrosol, respectively, under three irrigation treatments. The plants were either irrigated daily to 90% of water-holding capacity (FI), or irrigated with 70% volume of water used for FI to the whole root-zone (DI) or alternately to half root-zone (PRD). The results showed that plants grown in Anthrosol possessed greater leaf gas exchange rates, dry biomass and WUE while lower nutrients content compared to those grown in Ferrosol. Despite a negative effect on plant N content and WUE, WSB addition increased water-holding capacity, consequently improved leaf gas exchange, water uptake, biomass and K content resulting in an improved in the leaf quality of tobacco as exemplified by an increased leaf K content and a more appropriate N to K stoichiometric ratio. However, these effects were not evident upon SWB addition. Moreover, these responses to biochar addition were stronger in Ferrosol than in Anthrosol might be associated with its lower pH. Compared to FI, PRD slightly reduced photosynthetic rate but significantly decreased stomatal conductance, transpiration rate and leaf area, leading to a significant increase in intrinsic, instantaneous and plant WUE. Additionally, PRD was superior over DI in improving yield, WUE, N uptake under a same irrigation volume. It was concluded that WSB combined with PRD could be a promising practice to synergistically improve tobacco yield, quality and WUE by improving soil hydro-physical properties and nutrients bioavailability.

Biochar has been advocated as a sustainable and eco-friendly practice to improve soil fertility and crop productivity which could aid in the mitigation of climate change. Nonetheless, the combined effects of biochar and irrigation on tobacco growth and soil nutrients in diverse soil types have been incompletely explored. We applied a split-root experiment to investigate the impacts of amendment with 2% softwood- (WBC) and wheat-straw biochar (SBC) on growth responses and rhizosphere soil nutrients availability of tobacco plants grown in a Ferralsol and an Anthrosol. All plants within same soil type received same amount of water daily by either conventional deficit irrigation (CDI) or alternate wetting-drying cycles irrigation (AWD). Compared to the un-amended controls, SBC addition enhanced biomass, carbon (C)-, phosphorus (P)- and potassium (K)-pool in the aboveground organs especially in Anthrosol, despite a negative effect on aboveground nitrogen (N)-pool. Regardless of soil type, biochar combined with AWD lowered root diameter while increased root tissue mass density to engage the plant in an acquisitive strategy for resources, therefore altered leaves stoichiometry as exemplified by lowered N/K, C/P and N/P and increased C/N. The addition of SBC induced a liming effect by increasing Anthrosol soil pH which was further amplified by AWD, but was unaffected on Ferralsol. Moreover, compared to the controls, SBC and AWD increased available P and K, and total C, total N and C/N ratio in the rhizosphere soil which coincided with the lowered soil C and N isotope composition (δ13C and δ15N), though a slight reduction in C and N stocks under AWD. However, such effects were not evident with WBC might be associated with its natures. Thus, combined SBC/AWD application might be an effective strategy to synergistically overcome nutrients restriction and improve tobacco productivity by intensifying nutrients cycling and optimizing plant growth strategies.

The directors of the Iranian-Italian archaeological Expedition in Khuzistan, south-west Iran present the first results of a survey conducted in the plain of Izeh, one of the core sectors of the ancient Parthian vassal kingdom of Elymais. The Izeh plain is situated east of the fertile lowlands at the feet of the Bakhtiari mountains. From there many passes lead through the mountain range. The new survey adds new data to the archaeological exploration conducted by H.T. Wright in the same region....

Urban anthropogenic soils (UASs) are soils formed by: (1) Metapedogenesis, in which human additions of organic matter transform a pre-existing natural soil into a new profile requiring classification as a different type of soil, (2) Technopedogenesis, wherein a new soil profile is developed in artifact-bearing, human-deposited sediment comprised of a mechanical mixture of earth materials, and (3) Ekranopedogenesis, in which pre-existing soils are sealed beneath pavement and other impervious structures and materials. Human-forced melanization results in rapid organic matter accumulation, and because of substrate mixing and the addition of artifactual materials, UASs are generally in a state of thermodynamic disequilibrium which results in accelerated rates of soil formation. Thus, most UASs are characterized by ˆA-ˆC or ˆA-ˆBw-ˆC profiles, which have developed rapidly within only a few decades. In Soil Taxonomy (ST), UASs are distinguished as having formed in human-altered vs. human-transported materials, which correspond closely to Anthrosol vs. Technosol categories, respectively, in the World Reference Base (WRB). However, differentiae in ST do not correspond conveniently with land use type, whereas in the WRB, there is currently no provision for grave soils and several distinct types of UASs are lumped together as Spolic Technosols. Based on the working classification formulated herein, the most widespread UASs are Urbic (residential) and Ekranic (sealed) Technosols. Hortic (garden) and Nekric (cemetery) Anthrosols, and Industric (industrial) and Spolic (mine soils) Technosols, are relatively minor components of the typical urban landscape. UASs are expected to impact growing numbers of people as urbanization expands worldwide.

Made available in DSpace on 2020-12-12T02:08:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico Organic matter plays many roles in the soil ecosystem. One property of the substance concerns the metal complexation and interaction with organic contaminants. In this sense, the humic substances (HS), a heterogeneous mixture of compounds, naturally derived from degradation of biomass, have been widely studied in environmental sciences. Recent advances showed a new way to produce humic-like substances (HLS) through hydrothermal carbonization of biomass. Thus, this study aimed to evaluate the HLS of hydrochars, produced by using a mixture of sugarcane bagasse and vinasse with sulfuric acid added (1 and 4% v/v), and to assess their interactions with metal ions, (Fe(III), Al(III), Cu(II) and Co(II)) using EEM-PARAFAC and a two-dimensional FTIR correlation analysis. The results were compared to the humic substances extracted from the Amazonian Anthrosol, as a model of anthropogenic organic matter. NMR analysis showed that humic-like extracts from hydrochar are mainly hydrophobic, while the soil has a greater contribution of polar moieties. The HLS and HS showed similar complexation capacities for Fe(III), Al(III) and Cu(II) assays. For Co(II) HLS exhibited larger affinities than HS. Two-dimensional correlation analysis FTIR showed that chemical groups may undergo conformational alteration with metal additions to achieve more stable arrangements (higher stability constant). Therefore, these results contribute more knowledge about the mechanism of HS and metal ion interaction, as well as showing that HTC can be an interesting option for HLS production, to be used as humic based materials. Department of Chemistry and Environmental Sciences São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact Sciences (IBILCE), São José do Rio Preto Brazilian Agricultural Research Corporation (Embrapa Instrumentação), São Carlos Mediterranean Institute of Oceanography University Toulon Laboratório de Materiais Funcionais Avançados (LaMFA) Department of Physics Federal University of Ceará The Interdepartmental Research Centre on Nuclear Magnetic Resonance (NMR) for the Environment Agroo-food and New Materials (CERMANU) University of Naples Federico II, Portici Department of Physics São Paulo State University (UNESP) São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact Sciences (IBILCE), São José do Rio Preto Department of Chemistry and Environmental Sciences São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact Sciences (IBILCE), São José do Rio Preto Department of Physics São Paulo State University (UNESP) São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact Sciences (IBILCE), São José do Rio Preto FAPESP: 15/22954-1 FAPESP: 17/26718-6 CNPq: 307925/2012-9 CNPq: 445487/2014-3 Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico: PRONEX PR2-0101-00006.01.00/15

Archaeological Dark Earth (ADE) is a layer of anthrosol (syn. anthroposol) visually characterized by dark color mainly due to homogenous charcoal inclusion, and substantial enrichment by nutrients in comparison to surrounding soils. ADE is distributed from the tropics (Amazonian Terra preta, African ADE), moderate climatic zones (European ADE) up to the Arctic (kitchen middens). Although ADE soils have been studied also in other regions of the world, they have no special regional names. All types of ADE developed as a result of deliberate and/or unintentional deposition of domestic/occupational wastes, charred residues, bones, shells, and biomass ashes from prehistoric up to recent times. ADEs have optimum C : N ratio for effective mineralization, stable organic matter content, reduced acidity, higher CEC and C, N, P, Ca, Mn, Cu, Zn, Mn, Mg, Fe, Sr, and Ba content in comparison to surrounding soils. The unclear remains the level of ADEs enrichment by these elements as enrichment factors for different elements are based on different analytical approaches from plants-available up to total contents in the soil. Although generally highly productive, comparison of herbage production and crop yields between ADEs and natural soils are still rare. The distribution and persistence of anthropogenic activities leading to the formation of ADEs indicate that they are subject to the continual formation.

Artemisinin extracted from Artemisia annua has been used efficiently in malaria treatment since 2005. In this study, the variations in plant parameters (plant biomass, glandular trichome density, essential oil total chemical content, artemisinin production, and polyphenol oxidase (PPO) activity) were tested under different soil types (Luvisol, Gleysol, Anthrosol and sterile peat) and cultivation conditions (potted plants in semi-open field, and open field experiments) for plants inoculated with arbuscular mycorrhizal fungus (AMF) Rizophagus irregularis. Under semi-open field conditions, the AMF colonization of A. annua plant roots varied, and presented the highest percentage in Luvisol and sterile peat. The increase in the root colonization rate positively influenced some plant parameters (biomass, glandular trichome density, artemisinin concentration, essential oil quantity and composition), but no effects on PPO enzyme activity were detected. AMF fungus R. irregularis significantly increased the artemisinin content and essential oil yield of plants cultivated in Luvisol, Gleysol, Anthrosol and in peat. These soil types can offer appropriate conditions for A. annua cultivation and artemisinin production even on a smaller scale. Under open field conditions, low (about 5%) AMF colonization was observed. No differences in artemisin contents were detected, but essential oil yield significantly increased compared to control plants. AMF treatment increased beta-farnesene and germacrene D concentrations in Artemisia plants in the open field experiment.

Made available in DSpace on 2020-12-10T20:05:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01. Added 1 bitstream(s) on 2021-07-15T15:06:56Z : No. of bitstreams: 1 S0103-50532020000801623.pdf: 2286528 bytes, checksum: 92377067520636b9654d5e429405c88c (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) FUNCAP The chemical and spectroscopic characteristics of soil organic matter (SOM) isolated from Amazonian dark earth (ADE) and surrounding soil (SR) were evaluated according to the soil depth. The results showed opposite trends for the soils. While ADE featured SOM with a greater aromatic condensation degree and greater hydrophobicity in the top layer, the SR showed more aliphatic and polar SOM. The SOM arrangement from ADE was less hydrophobic, aromatic, and more polar in depth. In contrast, the SOM from SR showed an increase in molecular weight and hydrophobicity. Besides the aromatic protection in the SOM from ADE, there was organo-mineral protection through binding to soil minerals. This suggested that the SOM from ADE was protected by its hydrophobicity and interaction with minerals compared with that from the SR, thereby showing that the combination of both characteristics is important to create new technologies for soil carbon storage. Univ Estadual Paulista Julio de Mesquita Filho Un, Lab Estudos Ciencias Ambientais LECA, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil Embrapa Instrumentacao, BR-13560970 Sao Carlos, SP, Brazil Univ Fed Ceara, Lab Mat Funcionais Avancados LaMFA, Dept Fis, BR-60440554 Fortaleza, Ceara, Brazil Univ Estadual Paulista Julio de Mesquita Filho Un, Lab Estudos Ciencias Ambientais LECA, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil FAPESP: 15/22954-1 FAPESP: 2018/15733-7 FAPESP: 2017/15733-7 FAPESP: 2017/05575-2 FUNCAP: PRONEX PR2-0101-00006.01.00/15

Soils within archaeological sites may show magnetic properties due to the presence of magnetic minerals, such as magnetite and maghemite, which form during deposition of the soil or due to local fires. The similarities in the crystallographic structures of magnetite and maghemite lead to difficulties in the identification of these mineral phases. This work aims to study the genesis of Fe nodules at an archaeological site in a cave in quartzite with a very low Fe content and no spinel group minerals. The guiding hypotheses of the research are as follows: i) the abundant Fe nodules in all the studied stratigraphic layers are of pedogenic origin and were generated by local bonfires, and ii) these Fe nodules are composed of magnetite, maghemite, and hematite, and the conversion of magnetite to maghemite indicates pedogenic processes. Micromorphological analysis and Raman spectroscopy were used for mineral phase determination. The results confirm the in situ pedological nature of the Fe nodules associated with anthropogenic fires in the cave.

The potential for using biochar to reclaim degraded urban land into productive land needs to be verified to address the incipient loss of agricultural land. A pot experiment was conducted to evaluate the effect of wheat straw biochar (with four application rates including 0, 0.5%, 1%, and 2% w/w biochar to soil) on selected soil properties and crop growth (paddy rice was grown followed by wheat) in a compacted urban homestead soil (Anthrosol). Nitrogen use efficiency and ammonia volatilization were determined using stable isotope methodologies. Wheat straw biochar amendments elevated the soil pH, total C, and C/N ratio, and significantly lowered (P

The monitoring of carbon dioxide (CO2) in anthrosol showed CO2 concentrations ([CO2]) up to 10,000 ppmv in dependence on external conditions. During dry season, [CO2] oscillated in a diurnal cycle with mean amplitude about 1520 ppmv. [CO2] was strongly positively correlated with soil temperature, T(soil), (correlation coefficient r ~ 0.92). However, T(soil) lagged behind [CO2] by 55 min. Due to the phase shift, the [CO2]/T(soil) dependence showed typical hysteresis loop with a counterclockwise rotation. A simple model of two oscillating signals indicates that this direction of rotation would mean violation of causality. The lag of T(soil) behind [CO2] would be conceivable if heat and CO2 were transported to the point of measuring from soil top layer and the CO2 transport was faster than heat transport. An effect of photosynthesis on [CO2] via root respiration is not too probable at dry season because it works on a longer time scale. Nevertheless, the correlation of [CO2] with the illumination (IL) in spectral range of 380–720 nm did not rule out such possibility (correlation coefficient r = 0.63 at 4-hour lag of [CO2] behind IL). Wet season was simulated by artificial soil sprinkling: adding water to soil induced the strong/immediate increase of [CO2] which was attributed to enhanced heterotrophic respiration. The dependence [CO2] = f(WEx) where WEx is water excess in L m−2 was almost linear, but its slope increases exponentially with temperature. Based on this finding, the relation SH(z) = b1 × exp(b2 × T(soil)(z) / T0) × (θ(z) / Φ) + b3 (where SH(z) is heterotrophic respiration [mol m−3 s−1], T(soil)(z) is soil temperature [K], T0 is standard temperature [K], θ(z) is moisture [m3 m−3], Φ is soil total porosity [m3 m−3], z is vertical coordinate, b1, b2, b3 are parameters) was proposed. A participation of root respiration on immediate fluctuation of [CO2] is less probable. This would be possible only in case of pressure propagation through plant xylem/phloem system.

Structural changes in fulvic acid (FA) in response to fertilization strategies, especially P-deficiency fertilization, have critical implications for soil carbon dynamics. This study examined how long-term fertilization influenced chemical compositions of soil FA and its humification degree. Advanced solid-state 13C nuclear magnetic resonance techniques were used to evaluate structural changes of FAs from two soils (a Fluvisol and an Anthrosol) under four fertilizer treatments: organic fertilizer combined with or without NPK fertilizer (OF and NPKOF), deficient in phosphorus only (NK) and Control. The greater aromaticity, hydrophobicity and alkyl/O-alkyl (A/O-A) ratios of FAs were observed in the Anthrosol than in the Fluvisol. The Anthrosol FAs contained more alkyl and aromatic C but fewer O-alkyls (mostly being protonated) than did the Fluvisol FAs. Both FAs comprised some nonprotonated aromatics, which decreased with applications of organic and NK fertilizers. This trend was less obvious for the Anthrosol than for the Fluvisol. Organic fertilizer treatments (OF and NPKOF) in the Fluvisol increased the A/O-A ratio and aromaticity compared with P-deficient soils (NK and Control), indicating organic fertilization promoted the humification degree of its FA. The NK treatment in the Fluvisol increased H/C ratio of FA. Compared with the Fluvisol FAs, the Anthrosol FAs displayed similar chemical natures, implying their formation followed similar processes with a similar humification degree. The findings suggest that long-term fertilization differently influenced the FAs from the Fluvisol and Anthrosol. Clearly, the Anthrosol FAs shared more common features among the treatments compared with the Fluvisol FAs, whereas P-deficiency rendered the Fluvisol FAs simpler.

Soil organic carbon (SOC) sequestration in the soil of arable land has been recommended as a ‘win–win strategy’ for improving soil quality and crop productivity, and for mitigating the effects of climate change. With data from a 35‐year field experiment, we investigated the effects of organic manure and synthetic fertilizers on the mechanisms of organic carbon (OC) protection in macroaggregates and the relations between crop productivity and OC under an intensive wheat (Triticum aestivum L.) and maize (Zea mays L.) cropping system on an Anthrosol in northern China. The study involved nine treatments consisting of different combinations of synthetic fertilizers and organic manure. Soil samples taken from the 0–10‐cm and 10–20‐cm layers after 35 years of experimentation were separated into four physical fractions within the macroaggregates and analysed for changes in OC. In comparison with the control without any addition of fertilizer, long‐term application of nitrogen and phosphorus had no effects on SOC and OC contents of the macroaggregate fractions. In contrast, the application of organic manure significantly increased SOC and OC contents of macroaggregate fractions, apart from mineral‐associated organic carbon (MOC). Soil organic carbon was strongly and positively correlated with OC content in the intra‐microaggregate particulate organic carbon fraction (iPOC), indicating that SOC sequestration occurred primarily in the form of the physically protected particulate organic carbon fraction in the Anthrosol investigated here. A quadratic‐plateau model described the relation between crop yields and SOC well, and the critical SOC content, above which there was no yield response to increasing SOC, was about 9 g kg⁻¹, or 25 Mg ha⁻¹. Thus, the input of available C should be adjusted once this critical SOC content has been reached to guarantee the desired level of soil productivity and efficiency of SOC sequestration. HIGHLIGHTS: Long‐term application of dairy manure markedly increased SOC contents in plough layer. Manure application increased OC contents in macroaggregate fractions, except MOC. SOC was significantly and positively correlated with iPOC. The critical SOC content to obtain desired crop yield was ca. 9 g kg⁻¹ in an Anthrosol.

Soil evaporation is the main route of soil moisture loss and often exceeds precipitation in the arid and semi-arid regions of the Loess Plateau. This study was conducted to determine whether biochar addition could reduce soil evaporation in drylands. We measured the evaporative loss in five typical topsoils (0–20 cm) from the Loess Plateau, Shaanxi, China, that differed in texture (Eum-Orthic Anthrosol, Isohumisol, Loess, Sandy loess, and Aeolian sand) with five different biochar addition amounts (0, 10, 50, 100, and 150 g-biochar/kg soil) and three biochar particle sizes (2–1 mm, 1–0.25 mm, and