A rhizobox experiment with two phosphorus (P) treatments, zero-P (0 mg P kg-1) and plus-P (100 mg P kg-1) as Ca(H2PO4)2·H2O, was conducted to study the chemical and biochemical properties in the rhizosphere of tw...A rhizobox experiment with two phosphorus (P) treatments, zero-P (0 mg P kg-1) and plus-P (100 mg P kg-1) as Ca(H2PO4)2·H2O, was conducted to study the chemical and biochemical properties in the rhizosphere of two rice genotypes (cv. Zhongbu 51 and Pembe) different in P uptake ability and their relationship with the depletion of soil P fractions. Plant P uptake, pH, phosphatase activity, and soil P fractions in the rhizosphere were measured. Both total dry weight and total P uptake of Pembe were significantly (P < 0.05) higher than those of Zhongbu 51 in the zero-P and plus-P treatments. Significant depletions of resin-Pi, NaHCO3-Pi, NaHCO3-Po, and NaOH-Pi, where Pi stands for inorganic P and Po for organic P, were observed in the rhizosphere of both Zhongbu 51 and Pembe under both P treatments. Pembe showed a greater ability than Zhongbu 51 in depleting resin-Pi, NaHCO3-Pi, NaHCO3-Po, NaOH-Pi, and NaOH- Po in the rhizosphere. HCl-Pi and residual-P were not depleted in the rhizosphere of both genotypes, regardless of P treatments despite significant acidification in the rhizosphere of Pembe under zero-P treatment. Higher acid phosphatase (AcPME) activity and alkaline phosphatase (AlPME) activity were observed in the rhizosphere of both Zhongbu 51 and Pembe compared to the corresponding controls without plant. AcPME activity was negatively (P < 0.01) correlated to NaHCO3-Po concentration in the rhizosphere of both Zhongbu 51 and Pembe, suggesting that AcPME was associated with the mineralization of soil organic P.展开更多
Microorganisms capable of solubilizing and mineralizing phosphorus （P） pools in soils are considered vital in promoting P bioavallability. The study was conducted to screen and isolate inorganic P-solubilizing bacte...Microorganisms capable of solubilizing and mineralizing phosphorus （P） pools in soils are considered vital in promoting P bioavallability. The study was conducted to screen and isolate inorganic P-solubilizing bacteria （IPSB） and organic P-mineralizing bacteria （OPMB） in soils taken from subtropical flooded and temperate non-flooded soils, and to compare inorganic P-solubilizing and organic P-solubilizing abilities between IPSB and OPMB. Ten OPMB strains were isolated and identified as Bacillus cereus and Bacillus megaterium, and five IPSB strains as B. megaterium, Burkholderia caryophyUi, Pseudomonas cichorii, and Pseudomonas syringae. P-solubilizing and -mineralizing abilities of the strains were measured using the methods taking cellular P into account. The IPSB strains exhibited inorganic P-solubilizing abilities ranging between 25.4-41.7 μg P mL^-1 and organic P-mineralizing abilities between 8.2-17.8μg P mL^-1. Each of the OPMB strains also exhibited both solubilizing and mineralizing abilities varying from 4.4 to 26.5 μg P mL^-1 and from 13.8 to 62.8 μg P mL^-1, respectively. For both IPSB and OPMB strains, most of the P mineralized from the organic P source was incorporated into the bacterial cells as cellular P. A significantly negative linear correlation （P 〈 0.05） was found between culture pH and P solubilized from inorganic P by OPMB strains. The results suggested that P solubilization and mineralization could coexist in the same bacterial strain.展开更多
Beijing experienced a long-lasting pollution episode in April 2012. Here, the authors characterize the sources and evolution processes of the pollution, with a focus on a haze and a dust episode that occurred during 1...Beijing experienced a long-lasting pollution episode in April 2012. Here, the authors characterize the sources and evolution processes of the pollution, with a focus on a haze and a dust episode that occurred during 15-30 April. All submicron aerosol species （PM1） showed substantial increases during the haze episode （HE）, with nitrate being the largest, contributing on average 32.2% of the non-refractory PM;（NR-PM1） mass （maximum： -42.0%）, which was different from other seasons. Secondary inorganic aerosol （SIA） species （55.1 ± 23.8 lag m-3; SIA = nitrate, ammonium, sulfate） played enhanced roles in the haze formation, accounting for 66.5% of the total NR-PM1 mass. In contrast to the HE, organics exhibited their highest levels （8.9 ± 5.4 lag m-3） among the NR-PM aerosol species during the dust episode, accounting for 64.0% on average. SIAs exhibited low concentration levels （4.6 ± 4.2 μg m-3） during the dust episode, contributing only 34.0% to the total NR-PM1 mass. This study suggests that air quality improvement strategies should be designed according to aerosol particle characteristics and formation mechanisms.展开更多
Hydrographical parameters and phytoplankton assemblages were determined along the Pondicherry, Parangipettai and Nagapattinam coastal waters, southeast coast of India. All the hydrographical parameters such as sea sur...Hydrographical parameters and phytoplankton assemblages were determined along the Pondicherry, Parangipettai and Nagapattinam coastal waters, southeast coast of India. All the hydrographical parameters such as sea surface temperature, salinity, p H, total alkalinity, dissolved oxygen and nutrients like nitrate, nitrite, inorganic phosphate and reactive silicate, chlorophyll a and phytoplankton assemblages were studied for a period of five months(May, August, September 2010, March and November 2011). Over 121 species of phytoplankton represented by 93 species of diatoms, 16 species of dinoflagellates, 9 species of blue-green algae, 2 species of greens and 1 species of silicoflagellate were recorded. High phytoplankton species diversity was found in March 2011 when salinity and nitrate concentrations were low and reactive silicate and inorganic phosphates were moderate. Species diversity was low during May 2010 when increased sea surface temperature, salinity and low nutrients availability were observed. Coscinodiscus centralis, Diatoma vulgaris and Proboscia alata were dominant, especially Coscinodiscus sp. distributed in all stations whereas Skeletonema costatum, Odontella sinensis and Ditylum brightwellii were abundant in August and September 2010. From principal component analysis and multiple regression analysis, it is evident that variables like sea surface temperature and dissolved oxygen are the most important factors influencing the seasonal pattern of phytoplankton population.展开更多
Citrate, oxalate, tartrate and malate were added into soils during the growthperiod of ryegrass to study the effect of different organic ligands on the release of variousinorganic P (Pi) fractions in a yellow-brown so...Citrate, oxalate, tartrate and malate were added into soils during the growthperiod of ryegrass to study the effect of different organic ligands on the release of variousinorganic P (Pi) fractions in a yellow-brown soil and a paddy soil. The results showed that oxalatewas most effective in promoting the release of total Pi in the yellow-brown soil and tartrate in thepaddy soil. The dominant Pi fractions released from the yellow-brown soil were calcium phosphate(Ca-P) and aluminum phosphate (Al-P) and those from the paddy soil were iron phosphate (Fe-P) andreductant soluble phosphate (O-P) mobilized by tartrate. Phosphorous-mobilizing capability oforganic acids in the yellow-brown soil revealed the following order: oxalate > citrate > malate >tartrate. In the paddy soil, the order was tartrate > citrate ≈ oxalate > malate. It wasdemonstrated that organic ligands were different in their capabilities of mobilizing Pi and the sameorganic ligand showed also a discrepancy in mobilizing P in different soils. Although the additionof organic ligands into soils could increase the amount of P taken up by ryegrass, the more uptakeof P, however, was not only due to the more release of Pi, but also partly from organic P. In manycases, organic ligands promoted the release of the total Pi, while different fractions showeddifferent trends: some increased and others decreased.展开更多
Based on the recent research results on dry and wet deposition of nutrient elements and sulphate, we estimate the atmospheric flux of nutrient elements and sulphate to the southern Yellow Sea and the East China Sea in...Based on the recent research results on dry and wet deposition of nutrient elements and sulphate, we estimate the atmospheric flux of nutrient elements and sulphate to the southern Yellow Sea and the East China Sea in each season. The results suggest that the concentrations of nutrient elements and sulphate in aerosol and precipitation show an apparent seasonal cycle with the maximum values in winter and the minimum values in summer. Depositions of nitrate and sulphate are dominated by wet deposition, while the deposition for phosphate is mainly dry deposition. Moreover, compared with the riverine inputs, the atmospheric deposition may be the main source of dissolved inorganic nutrients in the southern Yellow Sea and the East China Sea.展开更多
A distinctive feature of phosphates is their special and significant ability to form inorganic polymeric compounds---condensed phosphates, which are destined to play a considerable role in our ＂high-tech＂ society in...A distinctive feature of phosphates is their special and significant ability to form inorganic polymeric compounds---condensed phosphates, which are destined to play a considerable role in our ＂high-tech＂ society in the future. Numerous olygophosphates, polyphosphates, double condensed phosphates and cyclophosphates with diverse formula, such as double tetra-, octa- and dodecaphosphates were obtained and described by us last years. The offered data are the outcomes of our scientific researches： of synthesis, analysis, and estimation of results in correlation with new achievements in inorganic polymer＇s chemistry. Many double condensed compounds, containing monovalent metals are obtained by us during systematic investigation of polycomponent systems, containing mono- and trivalent metals at temperature range 100-600 ~C. Synthesised condensed phosphates, in fact--inorganic polymers were examined in detail by chemical and thermogravimetric analysis, most compounds were examined by paper chromatography and the structures are determined by X-ray structural techniques/diffraction analysis. During our fundamental researches numerous new （about 70） unknown until now condensed phosphates have been obtained. Dependency of composition VS temperature and molar ratio, reliance of structure from duration of synthesis and radius of the ions are revealed.展开更多
Into the photooxidation process, several factors such as pH, time of irradiation, dose of UV light, lamp power, contaminant concentration, turbidity of the solution and the presence of salts can interfere with the pho...Into the photooxidation process, several factors such as pH, time of irradiation, dose of UV light, lamp power, contaminant concentration, turbidity of the solution and the presence of salts can interfere with the photodegradation of pollutants. This research aims to evaluate the influence of salts： NaCl, MgCl2, CaCI2, BaC12, CuCl2, Na2SO4, MgSO4, MnSO4, FeSO4, CuSO4, Na3PO4, K2CrO4 and K2Cr207 in concentrations of 0.0005 M, 0.005 M and 0.05 M during photodegradation of aqueous solution of 59.5 mg/L of nitrobenzene at a pH of 2.5. It was observed that the presence of salts such as CuCI2, CuSO4, FeSO4, K2CrO4 and K2Cr207 interfere negatively in the system UV/H202 applied for degradation of nitrobenzene; possibly by oxidation of Fe2＋ to Fe3＋ and Cu＋ to Cu2＋ in the Cr case, due to the difficulty of transforming the Cr6＋ to Cr3＋ or because these solutions have color and act as radiation absorbing filter.展开更多
A polyoxometalate-based complex [Mn(DMSO)5H2O]2SiMo12O40 has been synthe- sized and it crystallizes in triclinic, space group P with a = 11.863(2), b = 12.750(3), c = 13.255(3) , a = 83.62(3), b = 69.46(3), g = 87.14(...A polyoxometalate-based complex [Mn(DMSO)5H2O]2SiMo12O40 has been synthe- sized and it crystallizes in triclinic, space group P with a = 11.863(2), b = 12.750(3), c = 13.255(3) , a = 83.62(3), b = 69.46(3), g = 87.14(3), V = 1865.6(6) 3, Dc = 2.445 g/cm3, Z = 1, ?= 2.660 mm-1, Mr = 2746.56, F(000) = 1328, R = 0.0569, wR = 0.1190 and GOF = 1.125. The results of X-ray crystal analysis and IR spectrum show that there exists strong interaction between the heteropolyanions [SiMo12O40]4- and coordination cations [Mn(DMSO)5H2O]2+ in solid state.展开更多
The analysis of stable isotopes of sulfur(δ34S) is a useful tool for identifying sources of sulfur in soils. Concentrations and sulfur(S)isotopes of water-soluble sulfate(WSS), adsorbed sulfate(AS), residual sulfur(R...The analysis of stable isotopes of sulfur(δ34S) is a useful tool for identifying sources of sulfur in soils. Concentrations and sulfur(S)isotopes of water-soluble sulfate(WSS), adsorbed sulfate(AS), residual sulfur(RS), and total sulfur(TS) in uncultivated surface soils of four Chinese provinces were systematically analyzed for identifying sources of S in the soils. Green and healthy mosses(Haplocladium microphyllum) were sampled as bioindicators. The mean WSS concentration(27.8 ± 23.4 mg kg-1) in the surface soils was lower than those of AS(101.4 ± 57.0 mg kg-1) and RS(381.5 ± 256.7 mg kg-1). The mean δ34S values of WSS and AS were very similar(about2.0‰), lower than those of RS(8.0‰) and TS(6.1‰). A significant linear correlation was found between the δ34S values of AS and WWS(y = 1.0002x- 0.0557, P < 0.0001), indicating that sulfate adsorption in the soils did not markedly fractionate S. All S species in the soils of Guizhou Province were characterized by the lowest δ34S values, consistent with the most34S-depleted rainwater sulfate reported at Guiyang of Guizhou Province. The δ34S values of sulfate in mosses and rainwater previously reported were significantly linearly correlated with those of both WWS and AS in surface soils, suggesting that atmospheric S input was an important source for soil WSS and AS. However, there were no significant correlations between isotopic composition of rainwater sulfate and RS or TS.The slopes of all these significant linear correlations(soil/rainwater or soil/moss isotopic ratio) were 0.4–0.6, indicating that inorganic sulfate in the surface soils should be a result of mixing of deposited atmospheric sulfate with a more34S-depleted sulfate component possibly from mineralization of RS.展开更多
基金the National High Technology Research and Development Program (863 Program) of China(No.2001AA241025-1).
文摘A rhizobox experiment with two phosphorus (P) treatments, zero-P (0 mg P kg-1) and plus-P (100 mg P kg-1) as Ca(H2PO4)2·H2O, was conducted to study the chemical and biochemical properties in the rhizosphere of two rice genotypes (cv. Zhongbu 51 and Pembe) different in P uptake ability and their relationship with the depletion of soil P fractions. Plant P uptake, pH, phosphatase activity, and soil P fractions in the rhizosphere were measured. Both total dry weight and total P uptake of Pembe were significantly (P < 0.05) higher than those of Zhongbu 51 in the zero-P and plus-P treatments. Significant depletions of resin-Pi, NaHCO3-Pi, NaHCO3-Po, and NaOH-Pi, where Pi stands for inorganic P and Po for organic P, were observed in the rhizosphere of both Zhongbu 51 and Pembe under both P treatments. Pembe showed a greater ability than Zhongbu 51 in depleting resin-Pi, NaHCO3-Pi, NaHCO3-Po, NaOH-Pi, and NaOH- Po in the rhizosphere. HCl-Pi and residual-P were not depleted in the rhizosphere of both genotypes, regardless of P treatments despite significant acidification in the rhizosphere of Pembe under zero-P treatment. Higher acid phosphatase (AcPME) activity and alkaline phosphatase (AlPME) activity were observed in the rhizosphere of both Zhongbu 51 and Pembe compared to the corresponding controls without plant. AcPME activity was negatively (P < 0.01) correlated to NaHCO3-Po concentration in the rhizosphere of both Zhongbu 51 and Pembe, suggesting that AcPME was associated with the mineralization of soil organic P.
基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars, the Ministry of Education of the P.R. China.
文摘Microorganisms capable of solubilizing and mineralizing phosphorus （P） pools in soils are considered vital in promoting P bioavallability. The study was conducted to screen and isolate inorganic P-solubilizing bacteria （IPSB） and organic P-mineralizing bacteria （OPMB） in soils taken from subtropical flooded and temperate non-flooded soils, and to compare inorganic P-solubilizing and organic P-solubilizing abilities between IPSB and OPMB. Ten OPMB strains were isolated and identified as Bacillus cereus and Bacillus megaterium, and five IPSB strains as B. megaterium, Burkholderia caryophyUi, Pseudomonas cichorii, and Pseudomonas syringae. P-solubilizing and -mineralizing abilities of the strains were measured using the methods taking cellular P into account. The IPSB strains exhibited inorganic P-solubilizing abilities ranging between 25.4-41.7 μg P mL^-1 and organic P-mineralizing abilities between 8.2-17.8μg P mL^-1. Each of the OPMB strains also exhibited both solubilizing and mineralizing abilities varying from 4.4 to 26.5 μg P mL^-1 and from 13.8 to 62.8 μg P mL^-1, respectively. For both IPSB and OPMB strains, most of the P mineralized from the organic P source was incorporated into the bacterial cells as cellular P. A significantly negative linear correlation （P 〈 0.05） was found between culture pH and P solubilized from inorganic P by OPMB strains. The results suggested that P solubilization and mineralization could coexist in the same bacterial strain.
基金supported by the National Key Basic Research Program of China[grant number 2014CB447900]the National Natural Science Foundation of China[grant number 41305115]+2 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences[grant number XDB05020501]the Project of High-resolution Earth Observation System[grant number 05-Y30B02-9001-13/15-7-WX02]Commonwealth Project in Ministry of Environmental Protection[grant number 201309011]
文摘Beijing experienced a long-lasting pollution episode in April 2012. Here, the authors characterize the sources and evolution processes of the pollution, with a focus on a haze and a dust episode that occurred during 15-30 April. All submicron aerosol species （PM1） showed substantial increases during the haze episode （HE）, with nitrate being the largest, contributing on average 32.2% of the non-refractory PM;（NR-PM1） mass （maximum： -42.0%）, which was different from other seasons. Secondary inorganic aerosol （SIA） species （55.1 ± 23.8 lag m-3; SIA = nitrate, ammonium, sulfate） played enhanced roles in the haze formation, accounting for 66.5% of the total NR-PM1 mass. In contrast to the HE, organics exhibited their highest levels （8.9 ± 5.4 lag m-3） among the NR-PM aerosol species during the dust episode, accounting for 64.0% on average. SIAs exhibited low concentration levels （4.6 ± 4.2 μg m-3） during the dust episode, contributing only 34.0% to the total NR-PM1 mass. This study suggests that air quality improvement strategies should be designed according to aerosol particle characteristics and formation mechanisms.
基金the University Grants Commission,Govt.of India,New Delhi for financial support through UGCResearch Award(No.F.30-1/2014(SA-II)/RA-2014-16-SCTAM-4364 dated 05/02/2015)
文摘Hydrographical parameters and phytoplankton assemblages were determined along the Pondicherry, Parangipettai and Nagapattinam coastal waters, southeast coast of India. All the hydrographical parameters such as sea surface temperature, salinity, p H, total alkalinity, dissolved oxygen and nutrients like nitrate, nitrite, inorganic phosphate and reactive silicate, chlorophyll a and phytoplankton assemblages were studied for a period of five months(May, August, September 2010, March and November 2011). Over 121 species of phytoplankton represented by 93 species of diatoms, 16 species of dinoflagellates, 9 species of blue-green algae, 2 species of greens and 1 species of silicoflagellate were recorded. High phytoplankton species diversity was found in March 2011 when salinity and nitrate concentrations were low and reactive silicate and inorganic phosphates were moderate. Species diversity was low during May 2010 when increased sea surface temperature, salinity and low nutrients availability were observed. Coscinodiscus centralis, Diatoma vulgaris and Proboscia alata were dominant, especially Coscinodiscus sp. distributed in all stations whereas Skeletonema costatum, Odontella sinensis and Ditylum brightwellii were abundant in August and September 2010. From principal component analysis and multiple regression analysis, it is evident that variables like sea surface temperature and dissolved oxygen are the most important factors influencing the seasonal pattern of phytoplankton population.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No.G1999011806).
文摘Citrate, oxalate, tartrate and malate were added into soils during the growthperiod of ryegrass to study the effect of different organic ligands on the release of variousinorganic P (Pi) fractions in a yellow-brown soil and a paddy soil. The results showed that oxalatewas most effective in promoting the release of total Pi in the yellow-brown soil and tartrate in thepaddy soil. The dominant Pi fractions released from the yellow-brown soil were calcium phosphate(Ca-P) and aluminum phosphate (Al-P) and those from the paddy soil were iron phosphate (Fe-P) andreductant soluble phosphate (O-P) mobilized by tartrate. Phosphorous-mobilizing capability oforganic acids in the yellow-brown soil revealed the following order: oxalate > citrate > malate >tartrate. In the paddy soil, the order was tartrate > citrate ≈ oxalate > malate. It wasdemonstrated that organic ligands were different in their capabilities of mobilizing Pi and the sameorganic ligand showed also a discrepancy in mobilizing P in different soils. Although the additionof organic ligands into soils could increase the amount of P taken up by ryegrass, the more uptakeof P, however, was not only due to the more release of Pi, but also partly from organic P. In manycases, organic ligands promoted the release of the total Pi, while different fractions showeddifferent trends: some increased and others decreased.
基金This work is supported by the State"973"basic research program under contract(G19990437)the international cooperation program under contract(2001CB711004).
文摘Based on the recent research results on dry and wet deposition of nutrient elements and sulphate, we estimate the atmospheric flux of nutrient elements and sulphate to the southern Yellow Sea and the East China Sea in each season. The results suggest that the concentrations of nutrient elements and sulphate in aerosol and precipitation show an apparent seasonal cycle with the maximum values in winter and the minimum values in summer. Depositions of nitrate and sulphate are dominated by wet deposition, while the deposition for phosphate is mainly dry deposition. Moreover, compared with the riverine inputs, the atmospheric deposition may be the main source of dissolved inorganic nutrients in the southern Yellow Sea and the East China Sea.
文摘A distinctive feature of phosphates is their special and significant ability to form inorganic polymeric compounds---condensed phosphates, which are destined to play a considerable role in our ＂high-tech＂ society in the future. Numerous olygophosphates, polyphosphates, double condensed phosphates and cyclophosphates with diverse formula, such as double tetra-, octa- and dodecaphosphates were obtained and described by us last years. The offered data are the outcomes of our scientific researches： of synthesis, analysis, and estimation of results in correlation with new achievements in inorganic polymer＇s chemistry. Many double condensed compounds, containing monovalent metals are obtained by us during systematic investigation of polycomponent systems, containing mono- and trivalent metals at temperature range 100-600 ~C. Synthesised condensed phosphates, in fact--inorganic polymers were examined in detail by chemical and thermogravimetric analysis, most compounds were examined by paper chromatography and the structures are determined by X-ray structural techniques/diffraction analysis. During our fundamental researches numerous new （about 70） unknown until now condensed phosphates have been obtained. Dependency of composition VS temperature and molar ratio, reliance of structure from duration of synthesis and radius of the ions are revealed.
文摘Into the photooxidation process, several factors such as pH, time of irradiation, dose of UV light, lamp power, contaminant concentration, turbidity of the solution and the presence of salts can interfere with the photodegradation of pollutants. This research aims to evaluate the influence of salts： NaCl, MgCl2, CaCI2, BaC12, CuCl2, Na2SO4, MgSO4, MnSO4, FeSO4, CuSO4, Na3PO4, K2CrO4 and K2Cr207 in concentrations of 0.0005 M, 0.005 M and 0.05 M during photodegradation of aqueous solution of 59.5 mg/L of nitrobenzene at a pH of 2.5. It was observed that the presence of salts such as CuCI2, CuSO4, FeSO4, K2CrO4 and K2Cr207 interfere negatively in the system UV/H202 applied for degradation of nitrobenzene; possibly by oxidation of Fe2＋ to Fe3＋ and Cu＋ to Cu2＋ in the Cr case, due to the difficulty of transforming the Cr6＋ to Cr3＋ or because these solutions have color and act as radiation absorbing filter.
基金The project was supported by the Natural Science Foundation of Henan Province (NO. 004040300) and the Outstanding Youth Foundation of Henan Province (NO. 004031800)
文摘A polyoxometalate-based complex [Mn(DMSO)5H2O]2SiMo12O40 has been synthe- sized and it crystallizes in triclinic, space group P with a = 11.863(2), b = 12.750(3), c = 13.255(3) , a = 83.62(3), b = 69.46(3), g = 87.14(3), V = 1865.6(6) 3, Dc = 2.445 g/cm3, Z = 1, ?= 2.660 mm-1, Mr = 2746.56, F(000) = 1328, R = 0.0569, wR = 0.1190 and GOF = 1.125. The results of X-ray crystal analysis and IR spectrum show that there exists strong interaction between the heteropolyanions [SiMo12O40]4- and coordination cations [Mn(DMSO)5H2O]2+ in solid state.
基金supported by the National Natural Science Foundation of China(Nos.41173027,41273027,and 40721002)the West Light Foundation of the Chinese Academy of Sciences
文摘The analysis of stable isotopes of sulfur(δ34S) is a useful tool for identifying sources of sulfur in soils. Concentrations and sulfur(S)isotopes of water-soluble sulfate(WSS), adsorbed sulfate(AS), residual sulfur(RS), and total sulfur(TS) in uncultivated surface soils of four Chinese provinces were systematically analyzed for identifying sources of S in the soils. Green and healthy mosses(Haplocladium microphyllum) were sampled as bioindicators. The mean WSS concentration(27.8 ± 23.4 mg kg-1) in the surface soils was lower than those of AS(101.4 ± 57.0 mg kg-1) and RS(381.5 ± 256.7 mg kg-1). The mean δ34S values of WSS and AS were very similar(about2.0‰), lower than those of RS(8.0‰) and TS(6.1‰). A significant linear correlation was found between the δ34S values of AS and WWS(y = 1.0002x- 0.0557, P < 0.0001), indicating that sulfate adsorption in the soils did not markedly fractionate S. All S species in the soils of Guizhou Province were characterized by the lowest δ34S values, consistent with the most34S-depleted rainwater sulfate reported at Guiyang of Guizhou Province. The δ34S values of sulfate in mosses and rainwater previously reported were significantly linearly correlated with those of both WWS and AS in surface soils, suggesting that atmospheric S input was an important source for soil WSS and AS. However, there were no significant correlations between isotopic composition of rainwater sulfate and RS or TS.The slopes of all these significant linear correlations(soil/rainwater or soil/moss isotopic ratio) were 0.4–0.6, indicating that inorganic sulfate in the surface soils should be a result of mixing of deposited atmospheric sulfate with a more34S-depleted sulfate component possibly from mineralization of RS.
