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1.
Food Chem ; 367: 130667, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34339981

RESUMO

The main purpose of the present study was to investigate the effect of different fertilizers on the physicochemical properties, multi-element and volatile composition of cucumbers. All samples were divided into five groups according to different combinations and amounts of chicken manure, NPK 17-17-17 fertilizer and microbial fertilizer. The co-application of chicken manure (120,000 kg/ha) and NPK 17-17-17 fertilizer (750 kg/ha) achieved the best texture properties, whereas the addition of the microbial fertilizer at 6000 kg/ha significantly improved the color quality of cucumbers. Similarly, the co-application of chicken manure, NPK 17-17-17 fertilizer and microbial fertilizer at 6000 kg/ha enhanced the number and abundance of volatile components detected in the cucumbers. Cucumbers from the control group contained the highest levels of most of the determined elements. Overall, a combination of chicken manure, NPK 17-17-17 fertilizer and 6000 kg/ha microbial fertilizer is recommended as a relatively efficient fertilizer utilization for cucumbers.


Assuntos
Cucumis sativus , Fertilizantes , Agricultura , Fertilizantes/análise , Esterco , Solo
2.
Food Chem ; 367: 130734, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34359003

RESUMO

Isocycloseram is a new isoxazoline insecticide that can efficiently control the diamondback moth in cruciferous crops. The aim of this study was to establish a method for the determination of isocycloseram residues in/on cabbage and in the soil using HPLC-UV at 264 nm. A field test was conducted in December 2019 and 2020 to monitor isocycloseram dissipation in Jiangxi, China. Acetonitrile was used to extract isocycloseram from cabbage and soil. C18 and GCB were used to purify cabbage extracts, whereas soil extracts did not require purification. At the addition level of 0.01-1.0 mg/kg, the average recoveries in cabbage and soil were 91.81-109.95% and 89.89-104.08% respectively. After having applied 10% isocycloseram DC, isocycloseram dissipated faster in the cabbage matrix. Isocycloseram residues on cabbage leaves could be removed through simple cleaning methods, especially by soaking in 2% citric acid.


Assuntos
Brassica , Resíduos de Praguicidas , Poluentes do Solo , Cromatografia Líquida de Alta Pressão , Meia-Vida , Resíduos de Praguicidas/análise , Solo , Poluentes do Solo/análise
3.
J Hazard Mater ; 421: 126757, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34352522

RESUMO

Inhalation exposure and beryllium (Be) toxicity are well-known, but research on bioaccessibility from soils via different exposure pathways is limited. This study examined soils from a legacy radioactive waste disposal site using in vitro ingestion (Solubility Bioaccessibility Research Consortium [SBRC], physiologically based extraction test [PBET], in vitro gastrointestinal [IVG]), inhalation (simulated epithelial lung fluid [SELF]) and dynamic two-stage bioaccessibility (TBAc) methods, as well as 0.43 M HNO3 extraction. The results showed, 70 ±â€¯4.8%, 56 ±â€¯16.8% and 58 ±â€¯5.7% of total Be were extracted (gastric phase [GP] + intestinal phase [IP]) in the SBRC, PBET, and IVG methods, respectively. Similar bioaccessibility of Be (~18%) in PBET-IP and SELF was due to chelating agents in the extractant. Moreover, TBAc-IP showed higher extraction (20.8 ±â€¯2.0%) in comparison with the single-phase (SBRC-IP) result (4.8 ±â€¯0.23%), suggesting increased Be bioaccessibility and toxicity in the gastrointestinal tract when the contamination derives from the inhalation route. The results suggested Be bioaccessibility depends on solution pH; time of extraction; soil reactive fractions (organic-inorganic); particle size, and the presence of chelating agents in the fluid. This study has significance for understanding Be bioaccessibility via different exposure routes and the application of risk-based management of Be-contaminated sites.


Assuntos
Arsênio , Poluentes do Solo , Arsênio/análise , Berílio/toxicidade , Disponibilidade Biológica , Poluição Ambiental , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
4.
J Hazard Mater ; 421: 126790, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34358973

RESUMO

Acid mine drainage (AMD) system represents one of the most unfavorable habitats for microorganisms due to its low pH and high concentrations of metals. Compared to bacteria and fungi, our understanding regarding the response of soil protozoa to such extremely acidic environments remains limited. This study characterized the structures of protozoan communities inhabiting a terrace heavily contaminated by AMD. The sharp environmental gradient of this terrace was generated by annual flooding from an AMD lake located below, which provided a natural setting to unravel the environment-protozoa interactions. Previously unrecognized protozoa, such as Apicomplexa and Euglenozoa, dominated the extremely acidic soils, rather than the commonly recognized members (e.g., Ciliophora and Cercozoa). pH was the most important factor regulating the abundance of protozoan taxa. Metagenomic analysis of protozoan metabolic potential showed that many functional genes encoding for the alleviation of acid stress and various metabolic pathways were enriched, which may facilitate the survival and adaptation of protozoa to acidic environments. In addition, numerous co-occurrences between protozoa and bacterial or fungal taxa were observed, suggesting shared environmental preferences or potential bio-interactions among them. Future studies are required to confirm the ecological roles of these previously unrecognized protozoa as being important soil microorganisms.


Assuntos
Mineração , Solo , Ácidos , Bactérias , Microbiologia do Solo
5.
J Environ Manage ; 301: 113891, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731939

RESUMO

In recent decades, the innovative practice of management and valorization of agrozootechnical waste as energy through anaerobic digestion (AD) has been rapidly growing. However, whether applying digestate to soil as biofertilizer can be a source of antibiotics (ABs) and antibiotic resistance genes (ARGs) has not been fully investigated so far. In this work the ARGs responsible for sulfamethoxazole (SMX) resistance (sul1, sul2), ciprofloxacin (CIP) resistance (qnrS, qepA, aac-(6')-Ib-cr) and the mobile genetic element intl1, together with the concentrations of the antibiotics SMX and CIP, were measured in several anaerobic digesters located in Central Italy. Based on these results, the concentrations of antibiotics and ARGs which can potentially reach soil through amendment with digestate were also estimated. The highest CIP and SMX concentrations were found during winter and spring in anaerobic digesters. The highest ARG abundances were found for the aac-(6')-Ib-cr and sul2 genes. The overall results showed that application of digestate to soil does not exclude AB contamination and spread of ARGs in agroecosystems, especially in the case of ciprofloxacin, owing to its high intrinsic persistence.


Assuntos
Antibacterianos , Solo , Anaerobiose , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/genética , Esterco , Sulfametoxazol
6.
J Environ Manage ; 301: 113943, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731955

RESUMO

To explore the effects of different regulation modes on the soil structure and gas transport characteristics in seasonal permafrost regions, freeze-thaw cycles (FTCs) were used as boundary conditions and three typical soils on the Songnen Plain were used: black soil, baijiang soil and meadow soil. Four treatments were established: biochar addition (B1), straw addition (S1), biochar combined with straw addition (B1S1) and an untreated control (CK). The changes in the proportion of soil water-stable aggregates, total soil porosity (TP), soil water characteristic curves (SWRCs), soil dissolved organic carbon (DOC) and soil air permeability (PL) were analyzed. The results showed that biochar and straw influenced the structure of the three soil types. The proportions of large (2-0.5 mm) and medium (0.5-0.25 mm) aggregates increased significantly. The soil aggregate stability indexes of the treated soils were better than those of the CK, and the three-phase ratios of the treated soils were closer to ideal. The different treatments had particularly obvious effects on the black soil; the generalized soil structure index (GSSI) values reached 95.59, 94.36 and 98.74 in the B1, S1 and B1S1 treatments, respectively. An interaction effect was observed between biochar and straw. B1S1 had a stronger effect than the other treatments, and the soil water holding capacity was significantly improved (FC = 0.317 cm3 cm-3). Under the B1S1 treatment, the DOC contents in black soil, baijiang soil and meadow soil were 160.78 mg/kg, 272.828 mg/kg and 271.912 mg/kg, respectively. Moreover, biochar and straw combined effectively reduced PL fluctuations under FTCs and improved the long-term stability of the soil structure. These results can aid in rational straw and biochar use to achieve comprehensive agricultural waste utilization.


Assuntos
Solo , Água , Carbono , Carvão Vegetal
7.
J Environ Manage ; 301: 113940, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731964

RESUMO

Forest conversion can drastically impact carbon (C) and nutrient processes and microbial stoichiometry, which will modify soil organic C (SOC) stock. However, SOC stock dynamics and its underlying mechanisms induced by long-term forest conversion remain unclear. Three well-protected plantations converted from natural forests for 36 years were compared, i.e., Cryptomeria fortunei (CF), Metasequoia glyptostroboides (MG) and Cunninghamia lanceolata (CL), with a natural forest (NF) as a control. SOC stock size and stability across three soil depths (0-10, 10-30 and 30-60 cm) were examined with aggregate-based method. Forest floors and fine roots were treated as C and nutrient inputs while soil respiration (Rs) was treated as C output. Soil microbial biomass C, nitrogen and phosphorus were measured to calculate microbial stoichiometry, as well as microenvironment and soil physicochemical properties. The relationships between SOC stock (size and stability) and these factors were explored using structural equation model. The results showed that microbial stoichiometry had strong or strict homeostasis at each soil depth. At 0-10 cm soil deep, SOC stock size varied with tree species (following the rank of CL > NF ≈ CF > MG) but its stability increased in all forest conversion types, regulated by forest floor quantity and quality associated with Rs; at 10-30 cm soil deep, the SOC stock sizes decreased in CF and MG, but SOC stock stability increased in MG, jointly driven by fine root quality and microenvironment; at 30-60 cm soil deep, SOC stock size decreased but its stability increased in MG, whereas both its size and stability had few changes in CF or CL, modified by soil physicochemical property associated with microbial stoichiometry and Rs. Overall, the effects of microbial stoichiometry and microenvironment on SOC stock were not pronounced. Thus, SOC stock size changed with soil depth and tree species but its stability tended to be steady at all depths varying with tree species. These results suggest that SOC stock size and stability are mainly determined by self-regulation process of forest ecosystems over more than three-decade after forest conversion, which will help us more accurately assess C sequestration strategies regarding long-term forest conversion.


Assuntos
Sequestro de Carbono , Solo , Carbono/análise , China , Ecossistema , Florestas
8.
Sci Total Environ ; 802: 149665, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34450437

RESUMO

We compiled an extensive database of erosion and runoff measurements on erosion plots under natural rainfall in China. We used this database to analyse how soil loss by sheet and rill erosion and runoff in China were affected by land use, slope gradient, slope length and mean annual precipitation. Our results show that land use dominates the variation of soil loss and runoff: Soil loss and runoff rates on land covered by grass and trees are one to three orders of magnitude lower than rates on cropland. Slope gradient and slope length affect soil loss and runoff rates on cropland but there is no statistically significant effect on either soil loss or runoff on plots with a permanent vegetation cover. Runoff rates consistently increase with mean annual precipitation. The relationship between soil loss and mean annual precipitation is, on the contrary, nonlinear for all land use types, with a clear increase of soil loss with precipitation up to a mean annual precipitation of ca. 700 mm yr-1, a subsequent decline and a second rise when the mean annual precipitation exceeds ca. 1400 mm yr-1. We attribute this non-linear response to the interplay of an increasing rainfall erosivity and an increasing protection due to vegetation cover with increasing mean annual precipitation. This non-linear response implies that the effect of precipitation changes induced by climate change on the erosion risk depends on how both rainfall erosivity and vegetation cover change with changing climate. Our study provides important insights as to how soil loss and runoff in China are related to controlling factors and this will allow improving assessments of total soil erosion and runoff rates over the entire territory of China.


Assuntos
Sedimentos Geológicos , Chuva , China , Conservação dos Recursos Naturais , Monitoramento Ambiental , Solo , Erosão do Solo
9.
Sci Total Environ ; 802: 149729, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34454135

RESUMO

Atmospheric heavy metal deposition in agroecosystems has increased recently, especially in northern China, which poses serious risks to crop safety and human health via food chain. Wheat grains can accumulate high levels of Pb even when wheat is planted in soils with low levels of Pb. However, the influence of atmospheric deposition on the accumulation and distribution of Pb in wheat grain is still unclear. A field survey was conducted in three districts (A: a district with industrial and traffic pollution; B: a district with traffic pollution; and C: an unpolluted district) in Hebei Province, North China. The grain of wheat cultivated in district A accumulated more Pb from soil and atmospheric deposition than those in other districts, and the bran from district A contained 3.50 and 2.04 times more Pb than those from districts B and C, respectively. The Pb distribution pattern in wheat grain detected by laser ablation inductively coupled mass spectrometry (LA-ICP-MS) was characterized by accumulation mostly in the pericarp and seed coat rather than in the crease, embryo and endosperm. Furthermore, Pb isotopic data showed that airborne Pb was the major source (>50%) of Pb in wheat grain. Interestingly, average contributions of Pb from atmospheric deposition to white flour (78.22%) were higher than its contributions to bran (56.27%). In addition, wheat flag leaves were exposed to PbSO4 at the booting stage, and much greater Pb accumulation (0.33-0.48 mg/kg) was observed in exposed wheat grain than in the control (P < 0.05), PbSO4 constituted most (82.80-100%) of the Pb in the wheat grain. In summary, the results confirmed the efficient foliar Pb uptake and transfer from atmospheric deposition into wheat grain. It would be a new sight for understanding the contribution of airborne Pb to Pb accumulation in wheat grains.


Assuntos
Terapia a Laser , Metais Pesados , Poluentes do Solo , China , Grão Comestível/química , Monitoramento Ambiental , Humanos , Chumbo , Espectrometria de Massas , Solo , Poluentes do Solo/análise , Triticum
10.
Sci Total Environ ; 802: 149728, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34454139

RESUMO

Sampling design in soil science is critical because the lack of reliable methods and collecting samples requires tremendous work and resources. The aims were to obtain an optimal sampling design for assessing potentially toxic elements pollution using pilot Pb soil samples from the urban green space area of Shanghai, China. Two general steps have been used. The first step is to determine the optimum sample size against improving the prediction accuracy and monitoring costs using the spatial simulated annealing (SSA) algorithm. Secondly, we evaluated their likely placement of new extra sampling points by integrated SSA with k-means (SSA+ k-means) and expert-based (SSA+ expert-based) sampling methods. The improvement of sampling design by the integrated sampling approaches was evaluated using mean kriging variance (MKV), root mean square error (RMSE), and mean absolute percentage error (MAPE). The findings indicated that adding and placing 350 new monitoring points upon the existing sampling design by SSA increased the prediction accuracy by 64.35%. The MKV for the optimized SSA+ k-means sample was lower than by 4.12 mg/kg, 9.46 mg/kg compared with locations optimized by SSA and SSA+ expert-based method, respectively. Optimizing new sampling locations by SSA+ k-means sampling method was reduced MAPE by 9.26% and RMSE by 7.13 mg/kg compared to optimizing by SSA alone. However, there was no improvement in placing the new sampling points in SSA+ expert-based sampling method; instead, it increased the error by 8.11%. This paper shows integrating optimization approaches to evaluate the existing sampling design and optimize a new optimal sampling design.


Assuntos
Parques Recreativos , Solo , China , Monitoramento Ambiental , Poluição Ambiental
11.
Sci Total Environ ; 802: 149671, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34454147

RESUMO

The usage of reclaimed wastewater (RWW) for irrigation of agricultural soils is increasingly being acknowledged for reducing water consumption by promoting reuse of treated wastewater, and for the delivery of extant nutrients in the soil. The downside is that RWW may be a vector for contamination of soils with contaminants of emerging concern (CECs), if left uncontrolled. Its usage is anticipated to alter the soil properties, consequently also the soil microbial community. In the present study, soil microcosms were set to monitor how short periods (up to fourteen days) of RWW irrigation influence the soil ecosystem, namely its physicochemical properties, functioning, and colonising microbiota (differentiating fungi from bacteria). Two scenarios were studied: clean soil and soil contaminated (spiked) with 9 CECs, at conditions that limit any abiotic decay processes, monitoring along time fluctuations in the taxonomic and functional microbiota diversity. As shortly as fourteen days, the irrigation of either soil with RWW did not significantly (p > 0.05) alter its physicochemical properties and scarcely impacted the bioremediation processes of the CECs that showed decay levels ranging from 24% to 100%. Bacillus spp. dominance was enhanced along time in all the soil microcosms (reaching over 70% of the total abundance on the 7th day) but the RWW help to preserve, to some extent, high bacterial diversity. Besides, irrigation with RWW acted as a buffer of the soil mycobiota, limiting alterations in its composition caused either along time (to a minor degree) or due to contamination with CECs (to a great degree). This includes limiting the rise of Rhizopus sp. relative abundance. Collectively, our data support the utility of short-term periods of RWW irrigation for preserving the soil microbial diversity and functioning, especially when fungi are considered.


Assuntos
Microbiota , Águas Residuárias , Irrigação Agrícola , Solo , Microbiologia do Solo , Águas Residuárias/análise
12.
Sci Total Environ ; 802: 149865, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34455271

RESUMO

The heavy metal accumulation in the Tibet Plateau (TP) poses a serious ecologic risk to the health of human and the other biota. Given the TP far away from the large anthropogenic emission sources, the rapid development of traffic activities during last several decades possibly leads to the elevated heavy metal concentration in the roadside soils. Therefore, we comprehensively assessed the heavy metal distribution in the 0-5 cm and 15-20 cm depth soils located at 5 m, 50 m, and 100 m distance to the edge of two major roads among the different vegetation covers and climatic conditions in the TP to verify this hypothesis. Results show that most of heavy metal concentrations in soils of different distance to the major road display an insignificant difference. The Nemero Synthesis indexes which represent the risk of pollution for these regions almost range 1 to 2 (low pollution risk), except 12.7 (extreme pollution risk) at one site. These indicate the limited impacts from the traffic activities for the whole region, but at some specific sites with the elevated traffic pollution. The forest cover at the altitude of 3700-4100 m has the highest mercury accumulation due to the vegetation and climatic factors induced the higher atmospheric depositions and stronger complexation with the organic matters. The statistical analysis finally suggests the geogenic weathering processes, climate, terrain and vegetation play an important role in shaping heavy metal distribution along the roadside of the TP.


Assuntos
Metais Pesados , Poluentes do Solo , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Solo , Poluentes do Solo/análise , Tibet , Emissões de Veículos/análise
13.
Sci Total Environ ; 802: 149843, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34455279

RESUMO

Losses of microbial diversity in degraded ecosystems still have obscure consequences, especially when considering the interaction between arbuscular mycorrhizal fungi (AMF) and soil bacteria. This study investigates the effect of decreasing microbial biomass on mycorrhizal attributes and soil quality indicators. The dilution-to-extinction approach was applied in microcosms to search for associations among bacterial diversity, mycorrhizal attributes, and soil quality indicators. The experiment was conducted with four soil treatments (undiluted control 100 = D0, 10-3 = D3, 10-6 = D6, and 10-9 = D9) from a short-term (two years = 2Y) and a long-term (15 years = 15Y) coal mine revegetation area. Microcosms were inoculated with 300 spores of Acaulospora colombiana, Gigaspora albida, and Claroideoglomus etunicatum with millet as the host plant. Results included the total number of AMF spores, mycorrhizal colonization, soil aggregation, glomalin, fluorescein diacetate hydrolysis (FDA), basal soil respiration, microbial biomass, and soil bacterial microbiome. Larger differences were observed between areas than between dilution treatments within the sampling area. Attributes that presented differences in the dilutions compared to D0 2Y samples were mycorrhizal colonization (D0 = 85% and D9 = 43.3%), FDA (D0 = 77.2% and D9 = 55.5%), extractable glomalin-related soil protein (D0 = 0.09 and D9 = 0.11) and bacterial diversity (D0 = 7.3 and D6 = 5.3). D0 15Y samples presented differences in microbial biomass nitrogen (D0: 232.0) and bacterial diversity (D0: 7.9, D9: 5.6) compared to the dilutions. Bacterial microbiome present in the D0 samples formed distinct clusters as to other samples and correlated with soil aggregation and basal respiration attributes. Results suggest that AMF inoculation and dilution-to-extinction did not affect soil quality indicators preeminently, but the bacterial community is affected and can influence the process of environmental revegetation. A long-term revegetation period is substantial to improve quality indicators and establish the diversity of microorganisms and consequently revegetation in areas impacted by coal mining.


Assuntos
Minas de Carvão , Microbiota , Micorrizas , Biomassa , Fungos , Raízes de Plantas , Indicadores de Qualidade em Assistência à Saúde , Solo , Microbiologia do Solo
14.
Sci Total Environ ; 802: 149835, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34461468

RESUMO

Soil carbon supplementation is known to stimulate plant growth by improving soil fertility and plant nutrient uptake. However, the underlying process and chemical mechanism that could explain the interrelationship between soil carbon supplementation, soil micro-ecology, and the growth and quality of plant remain unclear. In this study, we investigated the influence and mechanism of soil carbon supplementation on the bacterial community, chemical cycling, mineral nutrition absorption, growth and properties of tobacco leaves. The soil carbon supplementation increased amino acid, carbohydrates, chemical energy metabolism, and bacterial richness in the soil. This led to increased content of sugar (23.75%), starch (13.25%), and chlorophyll (10.56%) in tobacco leaves. Linear discriminant analysis revealed 49 key phylotypes and significant increment of some of the Plant Growth-Promoting Rhizobacteria (PGPR) genera (Bacillus, Novosphingobium, Pseudomonas, Sphingomonas) in the rhizosphere, which can influence the tobacco growth. Partial Least Squares Path Modeling (PLS-PM) showed that soil carbon supplementation positively affected the sugar and starch contents in tobacco leaves by possibly altering the photosynthesis pathway towards increasing the aroma of the leaves, thus contributing to enhanced tobacco flavor. These findings are useful for understanding the influence of soil carbon supplementation on bacterial community for improving the yields and quality of tobacco in industrial plantation.


Assuntos
Carbono , Solo , Suplementos Nutricionais , Raízes de Plantas , Rizosfera , Microbiologia do Solo , Amido , Açúcares , Tabaco
15.
Sci Total Environ ; 802: 149813, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34461469

RESUMO

In China, excessive application of nitrogen (N) fertilizer is common in intensive apple production. To resolve issues of benefit reduction and environmental pollution caused by excessive N, a two-year trial was conducted in an apple orchard with a split-plot design, in which the main factor was the N level (500, 400, 300, and 200 kg N ha-1 year-1, expressed as TN, TN80%, TN60%, and TN40%, respectively) and the deputy factor was whether or not to add 3,4-dimethylpyrazole phosphate (DMPP, expressed as +D). The effects of N reduction combined with DMPP on soil N transformation, fruit quality, economic benefits, and environmental effects were investigated. The results showed that DMPP reduced the production of nitrate and its vertical migration by inhibiting the abundance of AOB amoA and decreased N2O emission by reducing nirKC1 levels. Moreover, N reduction combined with DMPP improved N use efficiency (26.67-49.35%) and reduced N loss rate (15.25-38.76%). Compared with TN, TN60% + D increased the content of anthocyanin and soluble sugar by 21.15% and 13.09%, respectively, and decreased environmental costs caused by NH3 volatilization and N2O emission by 33.84%, while maintaining yield and N utilization rate at relatively high levels. Considering the agronomic, economic and environmental benefits, on the basis of traditional N application rate, 40% N reduction combined with DMPP (TN60% + D) could ensure target yield, corresponding quality and economic benefits, maintain soil N fertility, and reduce the risk of N losses to the environment. The present research could provide references for green, efficient, and sustainable development of apple production.


Assuntos
Fertilizantes , Malus , Agricultura , China , Iodeto de Dimetilfenilpiperazina , Fertilizantes/análise , Frutas/química , Nitrogênio/análise , Solo
16.
Sci Total Environ ; 802: 149715, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34461472

RESUMO

Tidal marshes store large amounts of carbon; however, little is known about the patterns, magnitudes, and biophysical drivers that regulate CO2 efflux from these ecosystems. Due to harsh environmental conditions (e.g., flooding), it is difficult to measure continuous soil CO2 efflux in tidal marshes. These data are necessary to inform empirical and process-based models and to better quantify carbon budgets. We performed automated (30 min) and manual (bi-monthly) soil CO2 efflux measurements, for ~20 months, at two sites in a temperate tidal marsh: tall Spartina (TS; dominated by S. cynosuroides) and short Spartina (SS; dominated by S. alterniflora). These measurements were coupled with water quality, canopy spectral reflectance, and meteorological measurements. There were no consistent diel patterns of soil CO2 efflux, suggesting a decoupling of soil CO2 efflux with diel variations in temperature and tides (i.e., water level) showing a hysteresis effect. Mean soil CO2 efflux was significantly higher at SS (2.15 ± 1.60 µmol CO2 m-2 s-1) than at TS (0.55 ± 0.80 µmol CO2 m-2 s-1), highlighting distinct biogeochemical spatial variability. At the annual scale, air temperature explained >50% of the variability in soil CO2 efflux at both sites; and water level and salinity were secondary drivers of soil CO2 efflux at SS and TS, respectively. Annual soil CO2 efflux varied from 287-876 to 153-211 g C m-2 y-1 at SS and TS, respectively, but manual measurements underestimated the annual flux by <67% at SS and <23% at TS. These results suggest that measuring and modeling diel soil CO2 efflux variability in tidal marshes may be more challenging than previously expected and highlight large discrepancies between manual and automated soil CO2 efflux measurements. New technical approaches are needed to implement long-term automated measurements of soil CO2 efflux across wetlands to properly estimate the carbon balance of these ecosystems.


Assuntos
Solo , Áreas Alagadas , Dióxido de Carbono/análise , Ecossistema , Estações do Ano
17.
Sci Total Environ ; 802: 149861, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34461475

RESUMO

Biochar has been widely advocated due to its special properties and sustainability for agriculture soil amendment. The influencing mechanism of biochar on soil properties is a key aspect of quantifying and predicting its benefits and trade-offs. The contribution of biochar to both environmental and agricultural benefits has been deeply discussed and extensively reviewed, but few reviews have focused on modeling biochar effects. An overview of recent advances in biochar modeling is illustrated and approaches classified in this paper. Applications of a machine learning model, a deterministic model, and a numerical model to biochar are categorized and summarized. A discussion of the advantages and disadvantages of each model and a comparison among them are also provided. Finally, this paper gives many suggestions on narrowing the knowledge gap to advance biochar modeling. Further study of biochar modeling in management planning and design and application of the model results in agricultural systems will help accelerate the expansion of biochar's application scale and encourage the efficient utilization of waste in agricultural systems.


Assuntos
Carvão Vegetal , Poluentes do Solo , Agricultura , Solo , Poluentes do Solo/análise
18.
Sci Total Environ ; 802: 149788, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34461479

RESUMO

In Mexico, millions of tons of mining wastes are deposited in the open pit. Their content in potentially toxic elements (PTE) represents an environmental risk. In the tailings, pioneer plant communities are established, associated with a determined diversity of fungi; plants, and fungi are fundamental in the natural rehabilitation of mining wastes. The objective was to evaluate the impact of the natural establishment of two plant species on the microbial activity, on the composition of the fungal community, and on the mitigation of the effect of PTE in a contaminated mine tailing. In a tailing, we selected three sites: one non-vegetated; one vegetated by Reseda luteola, and one vegetated by Asphodelus fistulosus. In the substrates, we conducted a physical and chemical characterization; we evaluated the enzymatic activity, the mineralization of the carbon, and the concentration of PTE. We also determined the fungal diversity in the substrates and in the interior of the roots, and estimated the accumulation of carbon, nitrogen, phosphorus and PTE in plant tissues. The tailings had a high percentage of sand; the non-vegetated site presented the highest electric conductivity, and the plant cover reduced the concentration of PTE in the substrates. Plants increased the carbon content in tailings. The enzymatic activities of ß-glucosidase and dehydrogenase, and the mineralization of carbon were highest at the site vegetated with A. fistulosus. Both plant species accumulated PTE in their tissues and exhibited potential in the phytoremediation of lead (Pb), cadmium (Cd), and copper (Cu). Fungal diversity was more elevated at the vegetated sites than in the bare substrate. Ascomycota prevailed in the substrates; the substrates and the plants shared some fungal taxa, but other taxa were specific. The plant coverage and the rhizosphere promoted the natural attenuation and a rehabilitation of the extreme conditions of the mining wastes, modulated by the plant species.


Assuntos
Metais Pesados , Micobioma , Poluentes do Solo , Metais Pesados/análise , Mineração , Plantas , Rizosfera , Solo , Poluentes do Solo/análise
19.
Sci Total Environ ; 802: 149769, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34464786

RESUMO

Production, emission, and absorption of biogenic volatile organic compounds (BVOCs) in ecosystem soils and associated impacts of nutrient availability are unclear; thus, predictions of effects of global change on source-sink dynamic under increased atmospheric N deposition and nutrition imbalances are limited. Here, we report the dynamics of soil BVOCs under field conditions from two undisturbed tropical rainforests from French Guiana. We analyzed effects of experimental soil applications of nitrogen (N), phosphorus (P), and N + P on soil BVOC exchanges (in particular of total terpenes, monoterpenes, and sesquiterpenes), to determine source and sink dynamics between seasons (dry and wet) and elevations (upper and lower elevations corresponding to top of the hills (30 m high) and bottom of the valley). We identified 45 soil terpenoids compounds emitted to the atmosphere, comprising 26 monoterpenes and 19 sesquiterpenes; of these, it was possible to identify 13 and 7 compounds, respectively. Under ambient conditions, soils acted as sinks of these BVOCs, with greatest soil uptake recorded for sesquiterpenes at upper elevations during the wet season (-282 µg m-2 h-1). Fertilization shifted soils from a sink to source, with greatest levels of terpene emissions recorded at upper elevations during the wet season, following the addition of N (monoterpenes: 406 µg m-2 h-1) and P (sesquiterpenes: 210 µg m-2 h-1). Total soil terpene emission rates were negatively correlated with total atmospheric terpene concentrations. These results indicate likely shifts in tropical soils from sink to source of atmospheric terpenes under projected increases in N deposition under global change, with potential impacts on regional-scale atmospheric chemistry balance and ecosystem function.


Assuntos
Nitrogênio , Solo , Ecossistema , Fertilização , Florestas , Fósforo , Terpenos
20.
Sci Total Environ ; 802: 149796, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34464787

RESUMO

Elevated arsenic (As) in soil is of public concern due to the carcinogenicity. Phosphorus (P) strongly influences the adsorption, absorption, transport, and transformation of As in the soil and in organisms due to the similarity of the chemical properties of P and As. In soil, P, particularly inorganic P, can release soil-retained As (mostly arsenate) by competing for adsorption sites. In plant and microbial systems, P usually reduces As (mainly arsenate) uptake and affects As biotransformation by competing for As transporters. The intensity and pattern of PAs interaction are highly dependent on the forms of As and P, and strongly influenced by various biotic and abiotic factors. An understanding of the PAs interaction in 'soil-plant-microbe' systems is of great value to prevent soil As from entering the human food chain. Here, we review PAs interactions and the main influential factors in soil, plant, and microbial subsystems and their effects on the As release, absorption, transformation, and transport in the 'soil-plant-microbe' system. We also analyze the application potential of P fertilization as a control for As pollution and suggest the research directions that need to be followed in the future.


Assuntos
Arsênio , Poluentes do Solo , Arseniatos/análise , Arsênio/análise , Poluição Ambiental , Humanos , Fósforo , Plantas , Solo , Poluentes do Solo/análise
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