As one of the most important and essential macronutrients next to nitrogen,phosphorus(P)is important for plant development,but it is the least mobile nutrient element in plant and soil.Globally,P is mined from geologi...As one of the most important and essential macronutrients next to nitrogen,phosphorus(P)is important for plant development,but it is the least mobile nutrient element in plant and soil.Globally,P is mined from geological sediments and added to agricultural soils so as to meet the critical requirements of crop plants for agronomic productivity.Phosphorus exists in soil in both organic and inorganic forms.The various inorganic forms of the element in soil are salts with calcium,iron,and aluminum,whereas the organic forms come from decaying vegetation and microbial residue.There is a huge diversity of plant microbiomes(epiphytic,endophytic,and rhizospheric)and soil microbiomes that have the capability to solubilize the insoluble P and make it available to plant.The main mechanism for the solubilization of inorganic P is by the production of organic acids,which lowers soil pH,or by the production of acid and alkaline phosphatases,which causes the mineralization of organic P.The P-solubilizing and-mobilizing microorganisms belong to all three domains,comprising archaea,bacteria,and eukarya.The strains belonging to the genera Arthrobacter,Bacillus,Burkholderia,Natrinema,Pseudomonas,Rhizobium,and Serratia have been reported as efficient and potential P solubilizers.The use of P solubilizers,alone or in combination with other plant growth-promoting microbes as an eco-friendly microbial consortium,could increase the P uptake of crops,increasing their yields for agricultural and environmental sustainability.展开更多
Atmospheric nitrogen deposition is at a high level in some forests of South China. The effects of addition of exogenous N and P on soil organic carbon mineralization were studied to address: (1) if the atmospheric N d...Atmospheric nitrogen deposition is at a high level in some forests of South China. The effects of addition of exogenous N and P on soil organic carbon mineralization were studied to address: (1) if the atmospheric N deposition promotes soil C storage through decreasing mineralization; (2) if the soil available P is a limitation to organic carbon mineralization. Soils (0–10 cm) was sampled from monsoon evergreen broad-leaved forest (MEBF), coniferous and broad-leaved mixed forest (CBMF), and Pinus massoniana...展开更多
Phosphorus (P) released and transported from wetlands affects wetland ecosystems and surrounding water systems. Sediment samples from the Pelham Bay wetlands in the Bronx, NY, have been collected and analyzed. Analysi...Phosphorus (P) released and transported from wetlands affects wetland ecosystems and surrounding water systems. Sediment samples from the Pelham Bay wetlands in the Bronx, NY, have been collected and analyzed. Analysis of the sorption characteristics, P compound identification and P mineralization, showed significant correlations between the sorption maximum (Smax) and Ox-Fe (r = 0.894), ash-TP and HCl-Ca (r = 0.94), ash-TP and TOC (r = 0.96), as well as TOC vs HCl-Ca (r = 0.93). These results indicate that mineral content affects the OP content and the sorption process. P sorption maxima Smax ranged from 70.4 to 1667 mg/Kg, and the equilibrium P concentration EPC<sub>0</sub> ranged from 0.09 to 0.2 mg/L. The high Smax in most of the sites, fairly high EPC<sub>0</sub> and high percentages of Pr (>96%), indicate substantial amounts of P could be bioavailable for plant uptake in the water column under changing hydro-climatic conditions. Dominant P compounds are dihydroxyacetone phosphate (DHAP), phosphoenolpyruvates (PEP), inosine monophosphate (IMP), glucose-6-phosphate (G6P), nucleoside monophosphates (NMP), glycerophosphate (GlyP), polynucleotides (PolyN), and pyrophosphates (Pyrop). The active P pool could maintain substantial P bioavailability and potentially cause eutrophication. The mineralization of 7, 15 and 30 days in laboratory experiments indicates a decrease of NaHCO<sub>3</sub> and HCl, and an increase of NaOH.展开更多
In this study,the enhanced mineralization of p-fluoronitrobenzene(p-FNB)was achieved in a methane-based hollow-fiber membrane biofilm reactor(CH4-MBfR).A TOC removal of 73.2%was gained in CH4-MBfR with an influent p-F...In this study,the enhanced mineralization of p-fluoronitrobenzene(p-FNB)was achieved in a methane-based hollow-fiber membrane biofilm reactor(CH4-MBfR).A TOC removal of 73.2%was gained in CH4-MBfR with an influent p-FNB loading of 42―84 mg/L·d,while only 40.6%of TOC was removed in the corresponding control biological reactor(BR).Moreover,the reaction rate constant for TOC removal in CH4-MBfR was 2.48 times that of the BR.VFAs was only detected in CH4-MBfR,although oxidation elimination was the first step for p-FNB removal in both systems.Methylococcus and Methylononas were dominant strains in the CH4-MBfR,which may play an important role in converting CH4 to VFAs and then further enhancing the mineralization efficiency of p-FNB.展开更多
氮素矿化是决定土壤供氮能力的重要生态过程,也是目前国内外土壤氮循环研究的重点。养分添加在调节土壤的氮转化方面起着重要的作用。该文以内蒙古锡林河流域温带典型草原为研究对象,通过不同水平的氮(N)和磷(P)养分添加实验,利用树脂...氮素矿化是决定土壤供氮能力的重要生态过程,也是目前国内外土壤氮循环研究的重点。养分添加在调节土壤的氮转化方面起着重要的作用。该文以内蒙古锡林河流域温带典型草原为研究对象,通过不同水平的氮(N)和磷(P)养分添加实验,利用树脂芯原位培养法分析研究不同水平施氮、施磷对生长季草地土壤氮矿化的影响。结果表明:高氮处理对草地土壤硝态氮(NO3--N)、铵态氮(NH4+-N)及无机氮都有明显的影响,其中25 g N·m-2·a-1和10 g N·m-2·a-1高氮处理显著提高了无机氮含量,25 g N·m-2·a-1高氮处理显著增加土壤的NO3--N及NH4+-N含量。与施氮相比,施磷处理对土壤NO3--N、NH4+-N及无机氮的影响较为有限,只有12.5 g P2O5·m–2·a–1的磷处理显著促进了NO3--N及无机氮含量。高氮处理对草地土壤氮素转化有明显影响,其中25 g N·m-2·a-1高氮处理对净硝化速率、氨化速率及矿化速率都有显著的促进作用,说明高梯度的施氮处理有利于提高土壤的供氮能力。氮是内蒙古锡林河流域草原生态系统有机氮矿化的限制因子。与施氮相比,施磷处理对草地土壤氮转化的作用较为有限,仅有12.5 g P2O5·m–2·a–1+2 g N·m-2·a-1处理显著促进生长季中期的净氨化速率。说明施磷对土壤氮转化的影响弱于施氮的影响。养分添加显著提高了草地的地上生物量。养分添加情景下,土壤湿度与净矿化速率极显著相关,表明湿度是影响该区域温带草原土壤氮矿化的主效因素。环境因子(如有机碳含量、土壤全氮及土壤C/N)与不同氮处理下的净矿化速率之间显著相关,而土壤微生物碳、氮含量与土壤氮矿化均没有显著相关性。展开更多
南方丘陵红壤茶园长期受到酸沉降的胁迫,但茶树根际氮(N)、磷(P)转化过程对酸雨的响应及其机制尚不清楚.以江西典型丘陵红壤25年茶园为对象,开展p H 4.5、p H 3.5、p H 2.5及对照4种不同强度酸雨处理的原位模拟试验,于试验第3年测定根...南方丘陵红壤茶园长期受到酸沉降的胁迫,但茶树根际氮(N)、磷(P)转化过程对酸雨的响应及其机制尚不清楚.以江西典型丘陵红壤25年茶园为对象,开展p H 4.5、p H 3.5、p H 2.5及对照4种不同强度酸雨处理的原位模拟试验,于试验第3年测定根际和非根际土壤矿质N、速效P和相关酶的活性,并估测土壤N、P矿化速率,计算各变量的根际效应.结果表明:与对照相比,p H 4.5、p H 3.5和p H 2.5处理根际土壤NO3--N含量分别降低了7.1%、42.1%和49.9%,矿质N分别降低了6.4%、35.9%和40.3%,速效P分别降低了10.5%、41.1%和46.9%;根际氨化速率分别降低了18.7%、30.1%和44.7%,N净矿化速率分别降低了3.6%、12.7%和38.8%,P矿化速率分别降低了31.5%、41.8%和63.0%,但不同处理之间根际硝化速率差异不显著;根际土壤脲酶和酸性磷酸酶活性均表现为随酸雨加重呈增强的趋势(P<0.05).非根际土壤除NH4+-N外,其他有效N和P含量未随酸雨加重而改变;不同酸雨处理对非根际土壤氨化、硝化、N净矿化速率和P矿化速率的影响差异均不显著.根际NH4+-N、NO3--N、矿质N、氨化和净矿化速率均随着酸雨强度加重由正效应转变为负效应,而脲酶和酸性磷酸酶活性由负效应转变为正效应,但速效P和P矿化速率始终表现为负效应,硝化速率始终为正效应.综上所述,连续酸雨加重总体上抑制了根际N、P转化,降低其有效性,且不同程度改变其根际效应,从而影响茶园养分循环.展开更多
基金the Department of Biotechnology,Akal College of Agriculture,Eternal University and the Department of Environment,Science&Technology(DEST),India-funded project“Development of Microbial Consortium as Bio-inoculants for Drought and Low Temperature Growing Crops for Organic Farming in Himachal Pradesh”for providing the facilities and financial support to undertake the investigations。
文摘As one of the most important and essential macronutrients next to nitrogen,phosphorus(P)is important for plant development,but it is the least mobile nutrient element in plant and soil.Globally,P is mined from geological sediments and added to agricultural soils so as to meet the critical requirements of crop plants for agronomic productivity.Phosphorus exists in soil in both organic and inorganic forms.The various inorganic forms of the element in soil are salts with calcium,iron,and aluminum,whereas the organic forms come from decaying vegetation and microbial residue.There is a huge diversity of plant microbiomes(epiphytic,endophytic,and rhizospheric)and soil microbiomes that have the capability to solubilize the insoluble P and make it available to plant.The main mechanism for the solubilization of inorganic P is by the production of organic acids,which lowers soil pH,or by the production of acid and alkaline phosphatases,which causes the mineralization of organic P.The P-solubilizing and-mobilizing microorganisms belong to all three domains,comprising archaea,bacteria,and eukarya.The strains belonging to the genera Arthrobacter,Bacillus,Burkholderia,Natrinema,Pseudomonas,Rhizobium,and Serratia have been reported as efficient and potential P solubilizers.The use of P solubilizers,alone or in combination with other plant growth-promoting microbes as an eco-friendly microbial consortium,could increase the P uptake of crops,increasing their yields for agricultural and environmental sustainability.
基金the National Natural Science Foundation of China (No. 30725006, 40730102)the Chinese Ecological Research Net
文摘Atmospheric nitrogen deposition is at a high level in some forests of South China. The effects of addition of exogenous N and P on soil organic carbon mineralization were studied to address: (1) if the atmospheric N deposition promotes soil C storage through decreasing mineralization; (2) if the soil available P is a limitation to organic carbon mineralization. Soils (0–10 cm) was sampled from monsoon evergreen broad-leaved forest (MEBF), coniferous and broad-leaved mixed forest (CBMF), and Pinus massoniana...
文摘Phosphorus (P) released and transported from wetlands affects wetland ecosystems and surrounding water systems. Sediment samples from the Pelham Bay wetlands in the Bronx, NY, have been collected and analyzed. Analysis of the sorption characteristics, P compound identification and P mineralization, showed significant correlations between the sorption maximum (Smax) and Ox-Fe (r = 0.894), ash-TP and HCl-Ca (r = 0.94), ash-TP and TOC (r = 0.96), as well as TOC vs HCl-Ca (r = 0.93). These results indicate that mineral content affects the OP content and the sorption process. P sorption maxima Smax ranged from 70.4 to 1667 mg/Kg, and the equilibrium P concentration EPC<sub>0</sub> ranged from 0.09 to 0.2 mg/L. The high Smax in most of the sites, fairly high EPC<sub>0</sub> and high percentages of Pr (>96%), indicate substantial amounts of P could be bioavailable for plant uptake in the water column under changing hydro-climatic conditions. Dominant P compounds are dihydroxyacetone phosphate (DHAP), phosphoenolpyruvates (PEP), inosine monophosphate (IMP), glucose-6-phosphate (G6P), nucleoside monophosphates (NMP), glycerophosphate (GlyP), polynucleotides (PolyN), and pyrophosphates (Pyrop). The active P pool could maintain substantial P bioavailability and potentially cause eutrophication. The mineralization of 7, 15 and 30 days in laboratory experiments indicates a decrease of NaHCO<sub>3</sub> and HCl, and an increase of NaOH.
基金This research was supported by the National Natural Science Foundation of China(No.21307160)the Natural Science Foundation of Shandong Province(ZR2019MEE038)the Fundamental Research Funds for the Central Universities(19CX02038A).
文摘In this study,the enhanced mineralization of p-fluoronitrobenzene(p-FNB)was achieved in a methane-based hollow-fiber membrane biofilm reactor(CH4-MBfR).A TOC removal of 73.2%was gained in CH4-MBfR with an influent p-FNB loading of 42―84 mg/L·d,while only 40.6%of TOC was removed in the corresponding control biological reactor(BR).Moreover,the reaction rate constant for TOC removal in CH4-MBfR was 2.48 times that of the BR.VFAs was only detected in CH4-MBfR,although oxidation elimination was the first step for p-FNB removal in both systems.Methylococcus and Methylononas were dominant strains in the CH4-MBfR,which may play an important role in converting CH4 to VFAs and then further enhancing the mineralization efficiency of p-FNB.
文摘氮素矿化是决定土壤供氮能力的重要生态过程,也是目前国内外土壤氮循环研究的重点。养分添加在调节土壤的氮转化方面起着重要的作用。该文以内蒙古锡林河流域温带典型草原为研究对象,通过不同水平的氮(N)和磷(P)养分添加实验,利用树脂芯原位培养法分析研究不同水平施氮、施磷对生长季草地土壤氮矿化的影响。结果表明:高氮处理对草地土壤硝态氮(NO3--N)、铵态氮(NH4+-N)及无机氮都有明显的影响,其中25 g N·m-2·a-1和10 g N·m-2·a-1高氮处理显著提高了无机氮含量,25 g N·m-2·a-1高氮处理显著增加土壤的NO3--N及NH4+-N含量。与施氮相比,施磷处理对土壤NO3--N、NH4+-N及无机氮的影响较为有限,只有12.5 g P2O5·m–2·a–1的磷处理显著促进了NO3--N及无机氮含量。高氮处理对草地土壤氮素转化有明显影响,其中25 g N·m-2·a-1高氮处理对净硝化速率、氨化速率及矿化速率都有显著的促进作用,说明高梯度的施氮处理有利于提高土壤的供氮能力。氮是内蒙古锡林河流域草原生态系统有机氮矿化的限制因子。与施氮相比,施磷处理对草地土壤氮转化的作用较为有限,仅有12.5 g P2O5·m–2·a–1+2 g N·m-2·a-1处理显著促进生长季中期的净氨化速率。说明施磷对土壤氮转化的影响弱于施氮的影响。养分添加显著提高了草地的地上生物量。养分添加情景下,土壤湿度与净矿化速率极显著相关,表明湿度是影响该区域温带草原土壤氮矿化的主效因素。环境因子(如有机碳含量、土壤全氮及土壤C/N)与不同氮处理下的净矿化速率之间显著相关,而土壤微生物碳、氮含量与土壤氮矿化均没有显著相关性。
文摘南方丘陵红壤茶园长期受到酸沉降的胁迫,但茶树根际氮(N)、磷(P)转化过程对酸雨的响应及其机制尚不清楚.以江西典型丘陵红壤25年茶园为对象,开展p H 4.5、p H 3.5、p H 2.5及对照4种不同强度酸雨处理的原位模拟试验,于试验第3年测定根际和非根际土壤矿质N、速效P和相关酶的活性,并估测土壤N、P矿化速率,计算各变量的根际效应.结果表明:与对照相比,p H 4.5、p H 3.5和p H 2.5处理根际土壤NO3--N含量分别降低了7.1%、42.1%和49.9%,矿质N分别降低了6.4%、35.9%和40.3%,速效P分别降低了10.5%、41.1%和46.9%;根际氨化速率分别降低了18.7%、30.1%和44.7%,N净矿化速率分别降低了3.6%、12.7%和38.8%,P矿化速率分别降低了31.5%、41.8%和63.0%,但不同处理之间根际硝化速率差异不显著;根际土壤脲酶和酸性磷酸酶活性均表现为随酸雨加重呈增强的趋势(P<0.05).非根际土壤除NH4+-N外,其他有效N和P含量未随酸雨加重而改变;不同酸雨处理对非根际土壤氨化、硝化、N净矿化速率和P矿化速率的影响差异均不显著.根际NH4+-N、NO3--N、矿质N、氨化和净矿化速率均随着酸雨强度加重由正效应转变为负效应,而脲酶和酸性磷酸酶活性由负效应转变为正效应,但速效P和P矿化速率始终表现为负效应,硝化速率始终为正效应.综上所述,连续酸雨加重总体上抑制了根际N、P转化,降低其有效性,且不同程度改变其根际效应,从而影响茶园养分循环.
