Corn straw return to the field is a vital agronomic practice for increasing soil organic carbon(SOC)and its labile fractions,as well as soil aggregates and organic carbon(OC)associated with water-stable aggregates(WSA...Corn straw return to the field is a vital agronomic practice for increasing soil organic carbon(SOC)and its labile fractions,as well as soil aggregates and organic carbon(OC)associated with water-stable aggregates(WSA).Moreover,the labile SOC fractions play an important role in OC turnover and sequestration.The aims of this study were to determine how different corn straw returning modes affect the contents of labile SOC fractions and OC associated with WSA.Corn straw was returned in the following depths:(1)on undisturbed soil surface(NTS),(2)in the 0–10 cm soil depth(MTS),(3)in the 0–20 cm soil depth(CTS),and(4)no corn straw applied(CK).After five years(2014–2018),soil was sampled in the 0–20 and 20–40 cm depths to measure the water-extractable organic C(WEOC),permanganate oxidizable C(KMnO4-C),light fraction organic C(LFOC),and WSA fractions.The results showed that compared with CK,corn straw amended soils(NTS,MTS and CTS)increased SOC content by 11.55%–16.58%,WEOC by 41.38%–51.42%,KMnO4-C and LFOC by 29.84%–34.09%and 56.68%–65.36%in the 0–40 cm soil depth.The LFOC and KMnO4-C were proved to be the most sensitive fractions to different corn straw returning modes.Compared with CK,soils amended with corn straw increased mean weight diameter by 24.24%–40.48%in the 0–20 cm soil depth.The NTS and MTS preserved more than 60.00%of OC in macro-aggregates compared with CK.No significant difference was found in corn yield across all corn straw returning modes throughout the study period,indicating that adoption of NTS and MTS would increase SOC content and improve soil structure,and would not decline crop production.展开更多
Graphene oxide(GO),a carbon nanomaterial that is widely used in the environment and other industries,may pose potential risks to ecosystems,especially the soil ecosystem.Some soils in Northeast China are frequently po...Graphene oxide(GO),a carbon nanomaterial that is widely used in the environment and other industries,may pose potential risks to ecosystems,especially the soil ecosystem.Some soils in Northeast China are frequently polluted with cadmium(Cd) metal.However,there is no study on the influence of GO on the Cd-contaminated soil microbial community and soil chemical properties.In this study,Cd(100 mg kg^(-1))-polluted soils were treated with different concentrations of GO(0,25,50,150,250,and 500 mg L^(-1),expressed as T1,T2,T3,T4,T5,and T6,respectively) for 40 days.The treatment without Cd pollution and GO served as the control(CK).Then,we investigated the influence of the GO concentrations on the bacterial community and chemical properties of Cd-polluted Haplic Cambisols,the zonal soil in Northeast China.After GO addition,the richness and diversity indexes of the bacterial community in Cd-contaminated Haplic Cambisols initially increased by 0.05-33.92% at 25 mg L^(-1),then decreased by0.07-2.37% at 50 mg L^(-1),and then increased by 0.01-24.37%within 500 mg L^(-1) again.The species and abundance of bacteria varied with GO concentration,and GO significantly increased bacterial growth at 25 and 250 mg L^(-1).GO treatments influenced the bacterial community structure,and the order of similarity of the bacterial community structure was as follows:T4=T5> T1=T6> T2> T3> CK.Proteobacteria and Acidobacteria were the dominant bacteria,accounting for 36.0% and 26.2%,respectively,of soil bacteria.Different GO treatments also significantly affected the metabolic function of bacteria and further influenced the diversity of the bacterial community structure by affecting several key soil chemical properties:soil pH,organic matter and available potassium,phosphorus,and cadmium.Our results provide a theoretical basis for scientific and comprehensive evaluation of the environmental impacts of GO on the zonal forest soils of Northeast China.展开更多
Straw is widely incorporated into soil worldwide,but most studies have concentrated on the effects of straw mulching or incorporation with topsoil.To determine the effect of depth of straw incorporation on bacterial a...Straw is widely incorporated into soil worldwide,but most studies have concentrated on the effects of straw mulching or incorporation with topsoil.To determine the effect of depth of straw incorporation on bacterial and fungal communities,we established a field experiment in a region in Northeast China with Haplic Chernozems using four treatments:conventional tillage(CT,tillage to a depth of 15 cm with no straw incorporation),straw incorporation with conventional tillage(SCT,tillage to a depth of 15 cm),inversion tillage(IT,tillage to a depth of 35 cm)and straw incorporation with inversion tillage(SIT,tillage to a depth of 35 cm).The soils were managed by inversion to a depth of 15 or 35 cm after harvest.The results show that soil organic carbon content was significantly higher and pH and bulk density were significantly lower in the 15–35 cm layer in IT and SIT than CT and SCT.Fungal abundance was higher with straw incorporation,but fungal diversity was lower in the 0–15 cm layer in SCT and SIT than in CT and IT.Path length in the bacterial network was shorter and connectivity was higher in CT+SCT than in IT+SIT,leading to a more complex ecosystem,and the fungal network had opposite patterns.The key taxa in the phylum Actinobacteriota and Ascomycota in the microbial networks changed dramatically at the genus level following inversion tillage with straw amendment,which may increase bacterial network resistance to environmental disturbances and unstable fungal networks,resulting in large changes in the fungal community involved in the decomposition of recalcitrant straw-derived C and the more efficient acquisition of limiting resources.展开更多
Physical protection is one of the important ways to stabilize organic carbon in soils. In order to under- stand the role of soils as a carbon sink or source in global climatic change and carbon cycles and properly man...Physical protection is one of the important ways to stabilize organic carbon in soils. In order to under- stand the role of soils as a carbon sink or source in global climatic change and carbon cycles and properly manage soils as a carbon sink, we ought to know how many organic car- bon (OC) in a given soil could be protected. By a density fractionation approach and ultrasonic technique, each soil sample was divided into three fractions: free light fraction (free-LF), occluded fraction (occluded-LF) and heavy frac- tion (HF). The obtained fractions were analyzed for total OC content, carbohydrate content and recalcitrant OC content. The results showed: (ⅰ) In the whole soil profile, dominance of OC consistently decreased in the following order: HF, free-LF, occluded-LF. This suggested that OC in soils were mostly protected. From 0—10 to 60—80 cm horizons, the OC in free-LF decreased from 25.27% to 3.72%, while OC in HF they were increased from 72.57% to 95.39%. The OC in oc- cluded-LF was between 2.16% and 0.89%. (ⅱ) Organic carbon recalcitrance in free-LF was similar to that in HF, and was even higher than that in HF below the surface hori- zon. This suggested that free-LF was not always the most fresh and non-decomposed fraction. OM quality of HF was higher than that of free-LF in the surface 10 cm below, namely the protected OM had higher quality than free OM in these horizons.展开更多
The intensive use of petroleum hydrocarbon products has made them priority environmental pollutants.When petroleum hydrocarbons enter the soil,a change in physical,chemical,and biological properties is observed.The na...The intensive use of petroleum hydrocarbon products has made them priority environmental pollutants.When petroleum hydrocarbons enter the soil,a change in physical,chemical,and biological properties is observed.The natural restoration of oil-contaminated soils is a lengthy process;therefore,remediation is often required.The aim of this study is to assess the change in the ecological state of haplic chernozem soil contaminated with oil,fuel oil,and gasoline after remediation.The indicators of soil biological activity,such as phytotoxicity(germination,length of shoots and roots),the activity of oxidoreductase enzymes(catalase and dehydrogenases),and the total number of bacteria were studied.The effects of nitroammophoska fertilizer,sodium humate,biochar,and the biofertilizer“Baikal EM-1”on the ecological state of soils contaminated with oil,fuel oil,and gasoline were studied.Pollution with oil,fuel oil,and gasoline decreased the values of all biological indicators.The most sensitive indicator was the length of radish roots in soils polluted with oil,gasoline,and fuel oil after remediation with nitroammophoska and Baikal EM-1 addition.The length of roots was the most sensitive indicator when remediation was performed with biochar and sodium humate added to soil contaminated with oil and gasoline,and with contamination of haplic chernozem soil with fuel oil,the total number of bacteria was the most sensitive indicator.The most effective ameliorant to phytotoxicity indicators for oil pollution was a 1 D dose of biochar,for fuel oil it was 1 D biochar and 2 D sodium humate,and for gasoline it was a 2 D dose of biochar and Baikal EM-1.All ameliorants at most of the studied doses increased dehydrogenase activity,but increased catalase activity only in some cases.An increase in the total number of bacteria in oil-contaminated soils was promoted by biochar and nitroammophoska at a dose of 2 D.Nitroammophoska was the most effective in ameliorant in soils contaminated with fuel oil;in soils polluted with gasoline,all doses of ameliorant increased the number of bacteria equally.The stimulating effect of ameliorants on biological activity of oil-contaminated haplic chernozem were in the following sequence:nitroammophoska>biochar>sodium humate>Baikal EM-1.The 2 D biochar dose was most effective.The stimulation of biological indicators by ameliorants when soil was contaminated with fuel oil were in the following sequence:biochar>Baikal EM-1>sodium humate>nitroammophoska.The same sequence of ameliorant stimulation was observed in soil polluted with gasoline.The results of this study can be used to biodiagnose the ecological state of oil-contaminated soils after remediation.展开更多
Soil organic carbon （SOC）, soil microbial biomass carbon （SMBC） and SMBC quotient （SMBC/SOC, qSMBC） are key indexes of soil biological fertility because of the relationship to soil nutrition supply capacity. Yet...Soil organic carbon （SOC）, soil microbial biomass carbon （SMBC） and SMBC quotient （SMBC/SOC, qSMBC） are key indexes of soil biological fertility because of the relationship to soil nutrition supply capacity. Yet it remains unknown how these three indexes change, which limits our understanding about how soil respond to different fertilization practices. Based on a 22-yr （1990-2011） long-term fertilization experiment in northwest China, we investigated the dynamics of SMBC and qSMBC during the growing period of winter wheat, the relationships between the SMBC, qSMBC, soil organic carbon （SOC） concentrations, the carbon input and grain yield of wheat as well. Fertilization treatments were 1） nonfertilization （control）; 2） chemical nitrogen plus phosphate plus potassium （NPK）; 3） NPK plus animal manure （NPKM）; 4） double NPKM （hNPKM） and 5） NPK plus straw （NPKS）. Results showed that the SMBC and qSMBC were significantly different among returning, jointing, flowering and harvest stages of wheat under long-term fertilization. And the largest values were observed in the flowering stage. Values for SMBC and qSMBC ranged from 37.5 to 106.0 mg kg1 and 0.41 to 0.61%, respectively. The mean value rank of SMBC during the whole growing period of wheat was hNPKM〉NPK_M〉NPKS〉CK〉NPK. But there were no statistically significant differences between hNPKM and NPKM, or between CK and NPK. The order for qSMBC was NPKS〉NPKM〉CK〉hNPKM〉NPK. These results indicated that NPKS significantly increased the ratio of SMBC to SOC, i.e., qSMBC, compared with NPK fertilizer or other two NPKM fertilizations. Significant linear relationships were observed between the annual carbon input and SOC （P〈0.01） or SMBC （P〈0.05）, and between the relative grain yield of wheat and the SOC content as well （P〈0.05）. But the qSMBC was not correlated with the annual carbon input. It is thus obvious that the combination of manure, straw with mineral fertilizer may be benefit to increase SOC and improve soil quality than using only mineral fertilizer.展开更多
The study was to investigate the adsorption behavior of arsenite （As（HI）） and arsenate （As（V）） on two variable charge soils, i.e., Haplic Acrisol and Rhodic Ferralsol at different ionic strengths and pH with b...The study was to investigate the adsorption behavior of arsenite （As（HI）） and arsenate （As（V）） on two variable charge soils, i.e., Haplic Acrisol and Rhodic Ferralsol at different ionic strengths and pH with batch methods. Results indicated that the amount of As（HI） adsorbed by these two soils increased with increasing solution pH, whereas it decreased with increasing ionic strength under the acidic condition. This suggested that As（Ⅲ） was mainly adsorbed on soil positive charge sites through electrostatic attraction under the acidic condition. Moreover, intersects of As（Ⅴ） adsorption-pH curves at different ionic strengths （a characteristic pH） are obtained for both soils. It was noted that above this pH, the adsorption of As（Ⅴ） was increased with increasing ionic strength, whereas below it the reverse trend was true. Precisely the intersect pH was 3.6 for Haplic Acrisol and 4.5 for Rhodic Ferralsol, which was near the values of PZSE （soil point of zero salt effect） of these soils. The effects of ionic strength and pH on arsenate adsorption by these soils were interpreted by the adsorption model. The results of zeta potential suggested that the potential in adsorption plane becomes less negative with increasing ionic strength above soil PZSE and decreases with increasing ionic strength below soil PZSE. These results further supported the hypothesis of the adsorption model that the potential in the adsorption plane changes with ionic strength with an opposite trend to surface charge of the soils. Therefore, the change of the potential in the adsorption plane was mainly responsible for the change of arsenate adsorption induced by ionic strength on variable charge soils.展开更多
Repeated applications of bordeaux mixture （a blend of copper sulfate and calcium hydroxide） and pyrethroid insecticides （Pys） have led to elevated copper （Cu） and Pys concentrations in vineyard surface soils. To...Repeated applications of bordeaux mixture （a blend of copper sulfate and calcium hydroxide） and pyrethroid insecticides （Pys） have led to elevated copper （Cu） and Pys concentrations in vineyard surface soils. To understand the potential influence of Cu on the fate of Pys in the soil environment, we selected two Pys, cypermethrin （CPM） and lambda-cyhalothrin （A-CHT）, and two typical Chinese vineyard soils, Haplic Acrisol and Luvic Phaeozem, as experimental samples. The dissipation experiment was conducted at room temperature in the dark, and the transport of both Pys through the soils was investigated using soil thin-layer chromatography. The results showed that the transport of Pys in both soils increased as the Cu2＋ concentration increased from 0 to 100 mg L-1, and Pys were more transportable in Haplic Acrisol （HA） than in Luvic Phaeozem （LP） under the same experimental conditions. For CPM, only 100 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased Pys transport through both soils relative to water. Lambda-CHT was significantly （P〈0.05） transported through HA by all the Cu2＋ concentrations compared to water, and all but the 1 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased the transport of A-CHT through LP relative to water. However, the dissipation rates of CPM and λ-CHT decreased with the addition of Cu to soils. Our findings suggest that the risk of groundwater contamination by Pys increases in the soils with elevated Cu concentrations.展开更多
Content of macro- and microelements in plant and soil was studied after biochar, compost, digestate, lignite, and lignohumate application. Pot experiments were carried out in Phytotron CLF Plant Master （Wertingen, Ge...Content of macro- and microelements in plant and soil was studied after biochar, compost, digestate, lignite, and lignohumate application. Pot experiments were carried out in Phytotron CLF Plant Master （Wertingen, Germany）. As tested plant lettuce （Lactucasativa） was used. Elemental composition was determined by AAS and XRF spectroscopy. Macronutrients content （Ca, Mg, K, and P） was determined by Mehlich III. Total content of carbon and nitrogen were determined by LECO TruSpec CN analyser. Results showed that different exogenous organic amendments statistically significantly influenced macro and micronutrients content in soil and plant. Satisfactory C/N ratio for soil microorganisms was measured only after compost and digestate application. As concerns hazardous elements, no legislation limits were overstepped after application of the tested organic amendments. Bioavailability and their uptake by plants followed the order： Cd 〉 Mn 〉 Zn 〉 Fe.展开更多
The ecotoxicity of tellurium(Te)compounds(oxide and nitrate)is assessed by changing the biological properties of soils of contrasting properties:Haplic Chernozem(Loamic),Eutric Cambisol,and Eutric Arenosol.Soil stabil...The ecotoxicity of tellurium(Te)compounds(oxide and nitrate)is assessed by changing the biological properties of soils of contrasting properties:Haplic Chernozem(Loamic),Eutric Cambisol,and Eutric Arenosol.Soil stability was assessed by the most sensitive and informative biological indicators:microbiological(total number of bacteria),biochemical(catalase and dehydrogenase activity),and phytotoxic(changes in the length of wheat roots and shoots).Te contamination was simulated at concentrations of 0.5,1,3,10,and 30 possible permissible concentrations(PPC).It has been established that already at minimum concentrations of Te(0.5 and 1 PPC),the biological indicators of soils decrease.As a rule,a direct relationship between Te concentration and the degree of deterioration of the studied soil properties was observed.Te nitrate showed higher ecotoxicity than oxide.A stronger negative effect of Te contamination was manifested 10 and 30 days after contamination.After 90 days,the restoration of the biological properties of the soils was observed.Haplic Chernozem(Loamic)showed greater resistance to Te contamination than Haplic Cambisols Eutric and Eutric Arenosol.The obtained results can be used to predict environmental risks from soil contamination with Te and to develop maximum permissible concentrations of Te in soils of contrasting properties.展开更多
基金the National Natural Science Foundation of China(42077022)Key Research and Development Program of Jilin Province(20200402098NC).
文摘Corn straw return to the field is a vital agronomic practice for increasing soil organic carbon(SOC)and its labile fractions,as well as soil aggregates and organic carbon(OC)associated with water-stable aggregates(WSA).Moreover,the labile SOC fractions play an important role in OC turnover and sequestration.The aims of this study were to determine how different corn straw returning modes affect the contents of labile SOC fractions and OC associated with WSA.Corn straw was returned in the following depths:(1)on undisturbed soil surface(NTS),(2)in the 0–10 cm soil depth(MTS),(3)in the 0–20 cm soil depth(CTS),and(4)no corn straw applied(CK).After five years(2014–2018),soil was sampled in the 0–20 and 20–40 cm depths to measure the water-extractable organic C(WEOC),permanganate oxidizable C(KMnO4-C),light fraction organic C(LFOC),and WSA fractions.The results showed that compared with CK,corn straw amended soils(NTS,MTS and CTS)increased SOC content by 11.55%–16.58%,WEOC by 41.38%–51.42%,KMnO4-C and LFOC by 29.84%–34.09%and 56.68%–65.36%in the 0–40 cm soil depth.The LFOC and KMnO4-C were proved to be the most sensitive fractions to different corn straw returning modes.Compared with CK,soils amended with corn straw increased mean weight diameter by 24.24%–40.48%in the 0–20 cm soil depth.The NTS and MTS preserved more than 60.00%of OC in macro-aggregates compared with CK.No significant difference was found in corn yield across all corn straw returning modes throughout the study period,indicating that adoption of NTS and MTS would increase SOC content and improve soil structure,and would not decline crop production.
基金supported financially by the National Natural Science Foundation of China (31370613)the Fundamental Research Funds for the Central Universities(2572019CP15)。
文摘Graphene oxide(GO),a carbon nanomaterial that is widely used in the environment and other industries,may pose potential risks to ecosystems,especially the soil ecosystem.Some soils in Northeast China are frequently polluted with cadmium(Cd) metal.However,there is no study on the influence of GO on the Cd-contaminated soil microbial community and soil chemical properties.In this study,Cd(100 mg kg^(-1))-polluted soils were treated with different concentrations of GO(0,25,50,150,250,and 500 mg L^(-1),expressed as T1,T2,T3,T4,T5,and T6,respectively) for 40 days.The treatment without Cd pollution and GO served as the control(CK).Then,we investigated the influence of the GO concentrations on the bacterial community and chemical properties of Cd-polluted Haplic Cambisols,the zonal soil in Northeast China.After GO addition,the richness and diversity indexes of the bacterial community in Cd-contaminated Haplic Cambisols initially increased by 0.05-33.92% at 25 mg L^(-1),then decreased by0.07-2.37% at 50 mg L^(-1),and then increased by 0.01-24.37%within 500 mg L^(-1) again.The species and abundance of bacteria varied with GO concentration,and GO significantly increased bacterial growth at 25 and 250 mg L^(-1).GO treatments influenced the bacterial community structure,and the order of similarity of the bacterial community structure was as follows:T4=T5> T1=T6> T2> T3> CK.Proteobacteria and Acidobacteria were the dominant bacteria,accounting for 36.0% and 26.2%,respectively,of soil bacteria.Different GO treatments also significantly affected the metabolic function of bacteria and further influenced the diversity of the bacterial community structure by affecting several key soil chemical properties:soil pH,organic matter and available potassium,phosphorus,and cadmium.Our results provide a theoretical basis for scientific and comprehensive evaluation of the environmental impacts of GO on the zonal forest soils of Northeast China.
基金Under the auspices of Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28070100)the National Key Research and Development Program of China(No.2022YFD1500100)+1 种基金the National Natural Science Foundation of China(No.41807085)the Earmarked Fund for China Agriculture Research System(No.CARS04)。
文摘Straw is widely incorporated into soil worldwide,but most studies have concentrated on the effects of straw mulching or incorporation with topsoil.To determine the effect of depth of straw incorporation on bacterial and fungal communities,we established a field experiment in a region in Northeast China with Haplic Chernozems using four treatments:conventional tillage(CT,tillage to a depth of 15 cm with no straw incorporation),straw incorporation with conventional tillage(SCT,tillage to a depth of 15 cm),inversion tillage(IT,tillage to a depth of 35 cm)and straw incorporation with inversion tillage(SIT,tillage to a depth of 35 cm).The soils were managed by inversion to a depth of 15 or 35 cm after harvest.The results show that soil organic carbon content was significantly higher and pH and bulk density were significantly lower in the 15–35 cm layer in IT and SIT than CT and SCT.Fungal abundance was higher with straw incorporation,but fungal diversity was lower in the 0–15 cm layer in SCT and SIT than in CT and IT.Path length in the bacterial network was shorter and connectivity was higher in CT+SCT than in IT+SIT,leading to a more complex ecosystem,and the fungal network had opposite patterns.The key taxa in the phylum Actinobacteriota and Ascomycota in the microbial networks changed dramatically at the genus level following inversion tillage with straw amendment,which may increase bacterial network resistance to environmental disturbances and unstable fungal networks,resulting in large changes in the fungal community involved in the decomposition of recalcitrant straw-derived C and the more efficient acquisition of limiting resources.
基金the National Basic Research Program of China(Grant No.2002CB111505).
文摘Physical protection is one of the important ways to stabilize organic carbon in soils. In order to under- stand the role of soils as a carbon sink or source in global climatic change and carbon cycles and properly manage soils as a carbon sink, we ought to know how many organic car- bon (OC) in a given soil could be protected. By a density fractionation approach and ultrasonic technique, each soil sample was divided into three fractions: free light fraction (free-LF), occluded fraction (occluded-LF) and heavy frac- tion (HF). The obtained fractions were analyzed for total OC content, carbohydrate content and recalcitrant OC content. The results showed: (ⅰ) In the whole soil profile, dominance of OC consistently decreased in the following order: HF, free-LF, occluded-LF. This suggested that OC in soils were mostly protected. From 0—10 to 60—80 cm horizons, the OC in free-LF decreased from 25.27% to 3.72%, while OC in HF they were increased from 72.57% to 95.39%. The OC in oc- cluded-LF was between 2.16% and 0.89%. (ⅱ) Organic carbon recalcitrance in free-LF was similar to that in HF, and was even higher than that in HF below the surface hori- zon. This suggested that free-LF was not always the most fresh and non-decomposed fraction. OM quality of HF was higher than that of free-LF in the surface 10 cm below, namely the protected OM had higher quality than free OM in these horizons.
基金The research was carried out with the financial support of the grant of the President(MK-175.2022.5)the laboratory«Soil Health»of the Southern Federal University with the financial support of the Ministry of Science and Higher Education of the Russian Federation(agreement no.075-15-2022-1122)the project of the Ministry of Science and Higher Education of the Russian Federation to support the youth laboratory“Agrobiotechnologies for improving soil fertility and agricultural product quality”within the framework of the development program of the interregional scientific and educational center of the South of Russia(LABNOTS-21-01AB).
文摘The intensive use of petroleum hydrocarbon products has made them priority environmental pollutants.When petroleum hydrocarbons enter the soil,a change in physical,chemical,and biological properties is observed.The natural restoration of oil-contaminated soils is a lengthy process;therefore,remediation is often required.The aim of this study is to assess the change in the ecological state of haplic chernozem soil contaminated with oil,fuel oil,and gasoline after remediation.The indicators of soil biological activity,such as phytotoxicity(germination,length of shoots and roots),the activity of oxidoreductase enzymes(catalase and dehydrogenases),and the total number of bacteria were studied.The effects of nitroammophoska fertilizer,sodium humate,biochar,and the biofertilizer“Baikal EM-1”on the ecological state of soils contaminated with oil,fuel oil,and gasoline were studied.Pollution with oil,fuel oil,and gasoline decreased the values of all biological indicators.The most sensitive indicator was the length of radish roots in soils polluted with oil,gasoline,and fuel oil after remediation with nitroammophoska and Baikal EM-1 addition.The length of roots was the most sensitive indicator when remediation was performed with biochar and sodium humate added to soil contaminated with oil and gasoline,and with contamination of haplic chernozem soil with fuel oil,the total number of bacteria was the most sensitive indicator.The most effective ameliorant to phytotoxicity indicators for oil pollution was a 1 D dose of biochar,for fuel oil it was 1 D biochar and 2 D sodium humate,and for gasoline it was a 2 D dose of biochar and Baikal EM-1.All ameliorants at most of the studied doses increased dehydrogenase activity,but increased catalase activity only in some cases.An increase in the total number of bacteria in oil-contaminated soils was promoted by biochar and nitroammophoska at a dose of 2 D.Nitroammophoska was the most effective in ameliorant in soils contaminated with fuel oil;in soils polluted with gasoline,all doses of ameliorant increased the number of bacteria equally.The stimulating effect of ameliorants on biological activity of oil-contaminated haplic chernozem were in the following sequence:nitroammophoska>biochar>sodium humate>Baikal EM-1.The 2 D biochar dose was most effective.The stimulation of biological indicators by ameliorants when soil was contaminated with fuel oil were in the following sequence:biochar>Baikal EM-1>sodium humate>nitroammophoska.The same sequence of ameliorant stimulation was observed in soil polluted with gasoline.The results of this study can be used to biodiagnose the ecological state of oil-contaminated soils after remediation.
基金the National Natural Science Foundation of China (41061035, 41371247)the Project of Aid of Science and Technology in Xinjiang, China (201191140) for providing funding for this work
文摘Soil organic carbon （SOC）, soil microbial biomass carbon （SMBC） and SMBC quotient （SMBC/SOC, qSMBC） are key indexes of soil biological fertility because of the relationship to soil nutrition supply capacity. Yet it remains unknown how these three indexes change, which limits our understanding about how soil respond to different fertilization practices. Based on a 22-yr （1990-2011） long-term fertilization experiment in northwest China, we investigated the dynamics of SMBC and qSMBC during the growing period of winter wheat, the relationships between the SMBC, qSMBC, soil organic carbon （SOC） concentrations, the carbon input and grain yield of wheat as well. Fertilization treatments were 1） nonfertilization （control）; 2） chemical nitrogen plus phosphate plus potassium （NPK）; 3） NPK plus animal manure （NPKM）; 4） double NPKM （hNPKM） and 5） NPK plus straw （NPKS）. Results showed that the SMBC and qSMBC were significantly different among returning, jointing, flowering and harvest stages of wheat under long-term fertilization. And the largest values were observed in the flowering stage. Values for SMBC and qSMBC ranged from 37.5 to 106.0 mg kg1 and 0.41 to 0.61%, respectively. The mean value rank of SMBC during the whole growing period of wheat was hNPKM〉NPK_M〉NPKS〉CK〉NPK. But there were no statistically significant differences between hNPKM and NPKM, or between CK and NPK. The order for qSMBC was NPKS〉NPKM〉CK〉hNPKM〉NPK. These results indicated that NPKS significantly increased the ratio of SMBC to SOC, i.e., qSMBC, compared with NPK fertilizer or other two NPKM fertilizations. Significant linear relationships were observed between the annual carbon input and SOC （P〈0.01） or SMBC （P〈0.05）, and between the relative grain yield of wheat and the SOC content as well （P〈0.05）. But the qSMBC was not correlated with the annual carbon input. It is thus obvious that the combination of manure, straw with mineral fertilizer may be benefit to increase SOC and improve soil quality than using only mineral fertilizer.
基金supported by the Knowledge Innovation Program Foundation of the Chinese Academy of Sciences (No. KZCX2-YW-409)the National Natural Science Foundation of China (No. 20577054)
文摘The study was to investigate the adsorption behavior of arsenite （As（HI）） and arsenate （As（V）） on two variable charge soils, i.e., Haplic Acrisol and Rhodic Ferralsol at different ionic strengths and pH with batch methods. Results indicated that the amount of As（HI） adsorbed by these two soils increased with increasing solution pH, whereas it decreased with increasing ionic strength under the acidic condition. This suggested that As（Ⅲ） was mainly adsorbed on soil positive charge sites through electrostatic attraction under the acidic condition. Moreover, intersects of As（Ⅴ） adsorption-pH curves at different ionic strengths （a characteristic pH） are obtained for both soils. It was noted that above this pH, the adsorption of As（Ⅴ） was increased with increasing ionic strength, whereas below it the reverse trend was true. Precisely the intersect pH was 3.6 for Haplic Acrisol and 4.5 for Rhodic Ferralsol, which was near the values of PZSE （soil point of zero salt effect） of these soils. The effects of ionic strength and pH on arsenate adsorption by these soils were interpreted by the adsorption model. The results of zeta potential suggested that the potential in adsorption plane becomes less negative with increasing ionic strength above soil PZSE and decreases with increasing ionic strength below soil PZSE. These results further supported the hypothesis of the adsorption model that the potential in the adsorption plane changes with ionic strength with an opposite trend to surface charge of the soils. Therefore, the change of the potential in the adsorption plane was mainly responsible for the change of arsenate adsorption induced by ionic strength on variable charge soils.
基金Supported by the China Postdoctoral Science Foundation (No. 20090461068)the Jiangsu Provincial Planned Projects for Postdoctoral Research Funds, China (No. 1001021B)+1 种基金the Scientific Research Foundation for Talented Scholars of Jiangsu University, China(No. 10JDG039)the Open Fund of State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences (No. Y052010043)
文摘Repeated applications of bordeaux mixture （a blend of copper sulfate and calcium hydroxide） and pyrethroid insecticides （Pys） have led to elevated copper （Cu） and Pys concentrations in vineyard surface soils. To understand the potential influence of Cu on the fate of Pys in the soil environment, we selected two Pys, cypermethrin （CPM） and lambda-cyhalothrin （A-CHT）, and two typical Chinese vineyard soils, Haplic Acrisol and Luvic Phaeozem, as experimental samples. The dissipation experiment was conducted at room temperature in the dark, and the transport of both Pys through the soils was investigated using soil thin-layer chromatography. The results showed that the transport of Pys in both soils increased as the Cu2＋ concentration increased from 0 to 100 mg L-1, and Pys were more transportable in Haplic Acrisol （HA） than in Luvic Phaeozem （LP） under the same experimental conditions. For CPM, only 100 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased Pys transport through both soils relative to water. Lambda-CHT was significantly （P〈0.05） transported through HA by all the Cu2＋ concentrations compared to water, and all but the 1 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased the transport of A-CHT through LP relative to water. However, the dissipation rates of CPM and λ-CHT decreased with the addition of Cu to soils. Our findings suggest that the risk of groundwater contamination by Pys increases in the soils with elevated Cu concentrations.
文摘Content of macro- and microelements in plant and soil was studied after biochar, compost, digestate, lignite, and lignohumate application. Pot experiments were carried out in Phytotron CLF Plant Master （Wertingen, Germany）. As tested plant lettuce （Lactucasativa） was used. Elemental composition was determined by AAS and XRF spectroscopy. Macronutrients content （Ca, Mg, K, and P） was determined by Mehlich III. Total content of carbon and nitrogen were determined by LECO TruSpec CN analyser. Results showed that different exogenous organic amendments statistically significantly influenced macro and micronutrients content in soil and plant. Satisfactory C/N ratio for soil microorganisms was measured only after compost and digestate application. As concerns hazardous elements, no legislation limits were overstepped after application of the tested organic amendments. Bioavailability and their uptake by plants followed the order： Cd 〉 Mn 〉 Zn 〉 Fe.
基金support of the project of the Strategic Academic Leadership Program of the Southern Federal University(“Priority 2030”)(No.SP-12-24-04).
文摘The ecotoxicity of tellurium(Te)compounds(oxide and nitrate)is assessed by changing the biological properties of soils of contrasting properties:Haplic Chernozem(Loamic),Eutric Cambisol,and Eutric Arenosol.Soil stability was assessed by the most sensitive and informative biological indicators:microbiological(total number of bacteria),biochemical(catalase and dehydrogenase activity),and phytotoxic(changes in the length of wheat roots and shoots).Te contamination was simulated at concentrations of 0.5,1,3,10,and 30 possible permissible concentrations(PPC).It has been established that already at minimum concentrations of Te(0.5 and 1 PPC),the biological indicators of soils decrease.As a rule,a direct relationship between Te concentration and the degree of deterioration of the studied soil properties was observed.Te nitrate showed higher ecotoxicity than oxide.A stronger negative effect of Te contamination was manifested 10 and 30 days after contamination.After 90 days,the restoration of the biological properties of the soils was observed.Haplic Chernozem(Loamic)showed greater resistance to Te contamination than Haplic Cambisols Eutric and Eutric Arenosol.The obtained results can be used to predict environmental risks from soil contamination with Te and to develop maximum permissible concentrations of Te in soils of contrasting properties.
