Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small water...Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order： paddy fields （and vegetable farming） 〉 bamboo stands 〉 fruit trccs （and upland）. The top surface （0-15 cm） paddy fields （and vegetable farming） were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees （and upland） soils, respectively. Subsurface paddy soils （15-30 cm） were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils （0-15 cm） were 6.36, 3.63 and 3.20 times those in fruit tree （and upland） soils respectively. Soil microbial metabolic quotient was in the order： fruit trees （and upland） 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree （and upland） soils. Rates of soil organic C mineralization during incubation changed in the order： paddy fields 〉 bamboo stands 〉 fruit trees （and upland） and soil bacteria population： paddy fields 〉 fruit trees （and upland） 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees （and upland） 〉 forestry in values of the average well cell development （AWCD） and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.展开更多
Monitoring soil microbial communities can lead to better understanding of the transformation processes of organic carbon in soil. The present study investigated the changes of soil microbial communities during straw d...Monitoring soil microbial communities can lead to better understanding of the transformation processes of organic carbon in soil. The present study investigated the changes of soil microbial communities during straw decomposition in three fields, i.e., cropland, peach orchard and vineyard. Straw decomposition was monitored for 360 d using a mesh-bag method. Soil microbial metabolic activity and functional diversity were measured using the Biolog-Eco system. In all three fields, dried straws with a smaller size decomposed faster than their fresh counterparts that had a larger size. Dried corn straw decomposed slower than dried soybean straw in the early and middle stages, while the reverse trend was found in the late stage. The cropland showed the highest increase in microbial metabolic activity during the straw decomposition, whereas the peach orchard showed the lowest. There was no significant change in the species dominance or evenness of soil microbial communities during the straw decomposition. However, the species richness fluctuated significantly, with the peach orchard showing the highest richness and the cropland the lowest. With different carbon sources, the peach orchard utilised carbon the most, followed by the cropland and the vineyard. In all three fields, carbon was utilized in following decreasing order： saccharides〉amino acids〉polymers〉polyamines〉carboxylic acids〉aromatic compounds. In terms of carbon-source utilization, soil microbial communities in the peach orchard were less stable than those in the cropland. The metabolic activity and species dominance of soil microbial communities were negatively correlated with the straw residual percentage. Refractory components were primarily accumulated in the late stages, thus slowing down the straw decomposition. The results showed that dried and crushed corn straw was better for application in long-term fields. The diversity of soil microbial communities was more stable in cropland than in orchards during the straw decomposition.展开更多
Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental ...Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.展开更多
The allometric relationships between growth traits are critical to trees’fitness,yet the mechanisms by which slope position affects tree growth and allometry remain poorly understood.This study examined growth traits...The allometric relationships between growth traits are critical to trees’fitness,yet the mechanisms by which slope position affects tree growth and allometry remain poorly understood.This study examined growth traits and their allometric relationships in an 8-year-old Calocedrus macrolepis plantation in southwest China across three slope positions(upslope,mesoslope and downslope).The measured growth traits included tree height(H),diameter at breast height(D),crown size(Crown),wood volume(V)and height under branch(HUB).The study also explored spatial variations in soil properties and microbial communities.Results showed that slope position altered allometric growth pattern,with larger allometric exponents at downslope for H,D and V relative to Crown and HUB,suggesting improved wood growth.Soil nutrient levels(nitrogen,phosphorus and available potassium)and microbial diversity,particularly the relative abundance of bacterial phyla such as Actinobacteria and Chloroflexi,were greater at mesoslope and downslope.Our study identified phosphorus and potassium as key drivers of enhanced allometric relationships.Functional groups such as Endomycorrhizal and Ectomycorrhizal fungi,and functional groups involved in nitrogen cycling(Nitrogen respiration,Nitrate respiration),were strongly correlated with allometric exponents for D,V and Crown relative to HUB,suggesting their role in supporting structural growth and canopy expansion.These findings emphasize that variations in soil nutrients and microbial communities across slope positions regulate tree growth and allometry,with bacterial communities exerting a stronger influence than fungi.These insights contribute to sustainable forest management,particularly in optimizing planting site selection for improved tree growth in mountainous regions.展开更多
As an essential base for agricultural products in Baiquan County China,the black soil inthe Northeast region had soil nutrient contentsup to several times that of ordinary soil.However,over-exploitation and utilizatio...As an essential base for agricultural products in Baiquan County China,the black soil inthe Northeast region had soil nutrient contentsup to several times that of ordinary soil.However,over-exploitation and utilization in recent years led to a decline in the quality of black soil.Therefore,it is strategic significance to study the improvement of soil quality by different shelterbelts.In order to explore the interaction between soil microbial and nutrients,the soils under four shelterbelts(pure Pinus sylvestris forest,pure Larix gmelinii forest,mixed Pinus sylvestris forest and mixed Larix gmelinii forest)were used as the research materials in Baiquan County,Heilongjiang Province,China.The changes of soil physicochemical properties and soil microbial function genes were studied,and their interaction patterns were analyzed by Redundancy analysis(RDA).The results showed that the concentration changes of TOC(total organic carbon),TN(total nitrogen),NO_(3)^(-)-N(nitrate nitrogen concentration),NH_(4)^(+)-N(ammonium nitrogen),TP(total phosphorus)and SP(soil available phosphorus)were significantly(P<0.05)increased in rhizosphere soil under mixed Larix gmelinii forest.In non-rhizosphere soil,the concentration changes of TOC,TN,NO_(3)^(-)-N and AN(soil alkali hydrolyzed nitrogen)were significantly(P<0.05)increased under mixed Larix gmelinii forest.In a word,the concentration changes of TOC,TN,NO_(3)^(-)-N were significantly(P<0.05)increased in soil under mixed Larix gmelinii forest.In cropland soil,the concentration changes of NO_(3)^(-)-N,NH_(4)^(+)-N,TP and SP were significantly(P<0.05)increased besides pure Pinus sylvestris forest.The abundance analysis of soil function genes revealed that amoA-AOA,nifH,nirS,nosZ,narG and phoD were upregulated under the mixed Larix gmelinii forest.The changes in abundance of amoA-AOA and nirS played an important role in increasing soil nutrient concentration and promoting the utilization of soil nutrients.The study suggested the cropland soil quality was improved by the mixed Larix gmelinii forest,it should provide clear evidence for importance of the microbial-abundance in the soil nutrients improvement.展开更多
Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficien...Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficiency for chemical fertilizers. Therefore, we conducted an incubation experiment using an alkaline soil from Tianjin（p H 8.37–8.43） to evaluate the suppression effect of Trichoderma viride（T. viride） biofertilizer on NH3 volatilization, and compared the differences in microbial community structure among all samples. The results showed that viable T. viride biofertilizer（T） decreased NH3 volatilization by 42.21% compared with conventional fertilizer（（CK）, urea）, while nonviable T. viride biofertilizer（TS） decreased NH3 volatilization by 32.42%. NH3 volatilization was significantly higher in CK and sweet potato starch wastewater（SPSW） treatments during the peak period. T. viride biofertilizer also improved the transfer of ammonium from soil to sweet sorghum. Plant dry weights increased 91.23% and 61.08% for T and TS, respectively, compared to CK. Moreover, T. viride biofertilizer enhanced nitrification by increasing the abundance of ammonium-oxidizing archaea（AOA） and ammonium-oxidizing bacteria（AOB）. The results of high-throughput sequencing indicated that the microbial community structure and composition were significantly changed by the application of T. viride biofertilizer. This study demonstrated the immense potential of T. viride biofertilizer in reducing NH3 volatilization from alkaline soil and simultaneously improving the utilization of fertilizer N by sweet sorghum.展开更多
Soil microbial carbon metabolism is critical in wetland soil carbon cycling,and is also a research hotspot at present.However,most studies focus on the surface soil layer in the wetlands and the microorganisms associa...Soil microbial carbon metabolism is critical in wetland soil carbon cycling,and is also a research hotspot at present.However,most studies focus on the surface soil layer in the wetlands and the microorganisms associated with this layer.In this study,0-75 cm soil profiles were collected from five widely separated reed wetlands in the Songnen Plain,which has a large number of middle-high latitude inland saline-sodic wetlands.The Biolog-ECO method was used to determine the carbon metabolic activity and functional diversity of soil microorganisms.The results showed that soil carbon metabolic activity decreased with increasing soil depth.The carbon metabolic activity of soil microorganisms in the 60-75 cm layer was approximately 57.41%-74.60%of that in the 0-15 cm layer.The soil microbial Shannon index and utilization rate of amines decreased with an increase in soil depth,while the Evenness index and utilization rate of polymers tended to increase with soil depth.Dissolved organic carbon(DOC)is the most important factor affecting microbial carbon source utilization preference,because microorganisms mainly obtain the carbon source from DOC.The result of the correlation analysis showed that the soil microbial carbon metabolic activity,Shannon index,and Evenness index significantly correlated with soil total carbon(TC),microbial biomass carbon(MBC),DOC,total nitrogen(TN),ammonium nitrogen(NH_(4)^(+)-N),nitrate nitrogen(NO_(3)_(−)-N)contents,and electrical conductivity(EC).This study emphasized the important role of microbial carbon metabolic function in deep soil.展开更多
基金the National Natural Science Foundation of China （40471066） the Knowledge Innovation Program of the Chinese Academy of Sciences （KZCX3-SW-417）.
文摘Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order： paddy fields （and vegetable farming） 〉 bamboo stands 〉 fruit trccs （and upland）. The top surface （0-15 cm） paddy fields （and vegetable farming） were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees （and upland） soils, respectively. Subsurface paddy soils （15-30 cm） were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils （0-15 cm） were 6.36, 3.63 and 3.20 times those in fruit tree （and upland） soils respectively. Soil microbial metabolic quotient was in the order： fruit trees （and upland） 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree （and upland） soils. Rates of soil organic C mineralization during incubation changed in the order： paddy fields 〉 bamboo stands 〉 fruit trees （and upland） and soil bacteria population： paddy fields 〉 fruit trees （and upland） 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees （and upland） 〉 forestry in values of the average well cell development （AWCD） and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.
基金supported by the Soil Erosion and Dryland Farming on Loess Plateau of the State Key Laboratory of Chinese Academy of Sciences (K318009902-1310) the Shaanxi Province Innovative Engineering Project Coordinator (2011K01-48)
文摘Monitoring soil microbial communities can lead to better understanding of the transformation processes of organic carbon in soil. The present study investigated the changes of soil microbial communities during straw decomposition in three fields, i.e., cropland, peach orchard and vineyard. Straw decomposition was monitored for 360 d using a mesh-bag method. Soil microbial metabolic activity and functional diversity were measured using the Biolog-Eco system. In all three fields, dried straws with a smaller size decomposed faster than their fresh counterparts that had a larger size. Dried corn straw decomposed slower than dried soybean straw in the early and middle stages, while the reverse trend was found in the late stage. The cropland showed the highest increase in microbial metabolic activity during the straw decomposition, whereas the peach orchard showed the lowest. There was no significant change in the species dominance or evenness of soil microbial communities during the straw decomposition. However, the species richness fluctuated significantly, with the peach orchard showing the highest richness and the cropland the lowest. With different carbon sources, the peach orchard utilised carbon the most, followed by the cropland and the vineyard. In all three fields, carbon was utilized in following decreasing order： saccharides〉amino acids〉polymers〉polyamines〉carboxylic acids〉aromatic compounds. In terms of carbon-source utilization, soil microbial communities in the peach orchard were less stable than those in the cropland. The metabolic activity and species dominance of soil microbial communities were negatively correlated with the straw residual percentage. Refractory components were primarily accumulated in the late stages, thus slowing down the straw decomposition. The results showed that dried and crushed corn straw was better for application in long-term fields. The diversity of soil microbial communities was more stable in cropland than in orchards during the straw decomposition.
基金funded by the National Natural Science Foundation of China(NSFC31301843)the National Nonprofit Institute Research Grant of Chinese Academy of Agricultural Sciences(IARRP-202-5)
文摘Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.
基金supported by the Essential Scientific Research of Chinese National Nonprofit Institute(CAFYBB2021ZW003)National Natural Science Foundation of China(32022058)+1 种基金the Candidates of the Young and Middle-Aged Academic Leaders of Yunnan Province of China(202205AC160041)Yunnan Fundamental Research Projects(202201AT070258 and 202301AV070002)and Xingdian Talent Support Program(XDYC-QNRC-2022-0231).
文摘The allometric relationships between growth traits are critical to trees’fitness,yet the mechanisms by which slope position affects tree growth and allometry remain poorly understood.This study examined growth traits and their allometric relationships in an 8-year-old Calocedrus macrolepis plantation in southwest China across three slope positions(upslope,mesoslope and downslope).The measured growth traits included tree height(H),diameter at breast height(D),crown size(Crown),wood volume(V)and height under branch(HUB).The study also explored spatial variations in soil properties and microbial communities.Results showed that slope position altered allometric growth pattern,with larger allometric exponents at downslope for H,D and V relative to Crown and HUB,suggesting improved wood growth.Soil nutrient levels(nitrogen,phosphorus and available potassium)and microbial diversity,particularly the relative abundance of bacterial phyla such as Actinobacteria and Chloroflexi,were greater at mesoslope and downslope.Our study identified phosphorus and potassium as key drivers of enhanced allometric relationships.Functional groups such as Endomycorrhizal and Ectomycorrhizal fungi,and functional groups involved in nitrogen cycling(Nitrogen respiration,Nitrate respiration),were strongly correlated with allometric exponents for D,V and Crown relative to HUB,suggesting their role in supporting structural growth and canopy expansion.These findings emphasize that variations in soil nutrients and microbial communities across slope positions regulate tree growth and allometry,with bacterial communities exerting a stronger influence than fungi.These insights contribute to sustainable forest management,particularly in optimizing planting site selection for improved tree growth in mountainous regions.
基金funded by the Fundamental Research Funds for the Central Universities(Grant No.2572023CT11-01)Seed Industry Innovation Funds for Heilongjiang Province of China(Grant No.ZQTYB231700002)Key Research and Development Program of Heilongjiang Province(Grant No.JD22A008).
文摘As an essential base for agricultural products in Baiquan County China,the black soil inthe Northeast region had soil nutrient contentsup to several times that of ordinary soil.However,over-exploitation and utilization in recent years led to a decline in the quality of black soil.Therefore,it is strategic significance to study the improvement of soil quality by different shelterbelts.In order to explore the interaction between soil microbial and nutrients,the soils under four shelterbelts(pure Pinus sylvestris forest,pure Larix gmelinii forest,mixed Pinus sylvestris forest and mixed Larix gmelinii forest)were used as the research materials in Baiquan County,Heilongjiang Province,China.The changes of soil physicochemical properties and soil microbial function genes were studied,and their interaction patterns were analyzed by Redundancy analysis(RDA).The results showed that the concentration changes of TOC(total organic carbon),TN(total nitrogen),NO_(3)^(-)-N(nitrate nitrogen concentration),NH_(4)^(+)-N(ammonium nitrogen),TP(total phosphorus)and SP(soil available phosphorus)were significantly(P<0.05)increased in rhizosphere soil under mixed Larix gmelinii forest.In non-rhizosphere soil,the concentration changes of TOC,TN,NO_(3)^(-)-N and AN(soil alkali hydrolyzed nitrogen)were significantly(P<0.05)increased under mixed Larix gmelinii forest.In a word,the concentration changes of TOC,TN,NO_(3)^(-)-N were significantly(P<0.05)increased in soil under mixed Larix gmelinii forest.In cropland soil,the concentration changes of NO_(3)^(-)-N,NH_(4)^(+)-N,TP and SP were significantly(P<0.05)increased besides pure Pinus sylvestris forest.The abundance analysis of soil function genes revealed that amoA-AOA,nifH,nirS,nosZ,narG and phoD were upregulated under the mixed Larix gmelinii forest.The changes in abundance of amoA-AOA and nirS played an important role in increasing soil nutrient concentration and promoting the utilization of soil nutrients.The study suggested the cropland soil quality was improved by the mixed Larix gmelinii forest,it should provide clear evidence for importance of the microbial-abundance in the soil nutrients improvement.
基金supported by the National Science Fund Projects (Nos. 41371266 and 31670507)Innovation in Cross-functional Team Program of the Chinese Academy of Sciences (No. 2015)+1 种基金the Key Research Program of Chinese Academy of Sciences (No. ZDRW-ZS-2016-5)the Key State Science and Technology Program of China (No. 2015ZX07206-006)
文摘Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficiency for chemical fertilizers. Therefore, we conducted an incubation experiment using an alkaline soil from Tianjin（p H 8.37–8.43） to evaluate the suppression effect of Trichoderma viride（T. viride） biofertilizer on NH3 volatilization, and compared the differences in microbial community structure among all samples. The results showed that viable T. viride biofertilizer（T） decreased NH3 volatilization by 42.21% compared with conventional fertilizer（（CK）, urea）, while nonviable T. viride biofertilizer（TS） decreased NH3 volatilization by 32.42%. NH3 volatilization was significantly higher in CK and sweet potato starch wastewater（SPSW） treatments during the peak period. T. viride biofertilizer also improved the transfer of ammonium from soil to sweet sorghum. Plant dry weights increased 91.23% and 61.08% for T and TS, respectively, compared to CK. Moreover, T. viride biofertilizer enhanced nitrification by increasing the abundance of ammonium-oxidizing archaea（AOA） and ammonium-oxidizing bacteria（AOB）. The results of high-throughput sequencing indicated that the microbial community structure and composition were significantly changed by the application of T. viride biofertilizer. This study demonstrated the immense potential of T. viride biofertilizer in reducing NH3 volatilization from alkaline soil and simultaneously improving the utilization of fertilizer N by sweet sorghum.
基金the Jilin Scientific and Technological Development Program(20210101091JC)the National Natural Science Foundation of China(41730643,41871090)the Innovation Team Project of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(2022CXTD02).
文摘Soil microbial carbon metabolism is critical in wetland soil carbon cycling,and is also a research hotspot at present.However,most studies focus on the surface soil layer in the wetlands and the microorganisms associated with this layer.In this study,0-75 cm soil profiles were collected from five widely separated reed wetlands in the Songnen Plain,which has a large number of middle-high latitude inland saline-sodic wetlands.The Biolog-ECO method was used to determine the carbon metabolic activity and functional diversity of soil microorganisms.The results showed that soil carbon metabolic activity decreased with increasing soil depth.The carbon metabolic activity of soil microorganisms in the 60-75 cm layer was approximately 57.41%-74.60%of that in the 0-15 cm layer.The soil microbial Shannon index and utilization rate of amines decreased with an increase in soil depth,while the Evenness index and utilization rate of polymers tended to increase with soil depth.Dissolved organic carbon(DOC)is the most important factor affecting microbial carbon source utilization preference,because microorganisms mainly obtain the carbon source from DOC.The result of the correlation analysis showed that the soil microbial carbon metabolic activity,Shannon index,and Evenness index significantly correlated with soil total carbon(TC),microbial biomass carbon(MBC),DOC,total nitrogen(TN),ammonium nitrogen(NH_(4)^(+)-N),nitrate nitrogen(NO_(3)_(−)-N)contents,and electrical conductivity(EC).This study emphasized the important role of microbial carbon metabolic function in deep soil.
