共查询到20条相似文献，搜索用时 171 毫秒
1.
土地利用史对水田甲烷的排放和甲烷植物的影响 总被引：1，自引：1，他引：1
The characteristics of methane emission were compared among six types of upland and paddy soils developed from different materials with distinct physical and chemical properties after planting rice.The fluxes of methane emission in submerged soils from the upland were obviously lower than those from the paddy rice field.The flux of methane emission in the paddy soil developed from fluvo-aquic soil was the largest among all the types of soils.Planting of rice was heplful to emission of methane in soils.The amounts of various groups of methanogenic flora were conformed with the differences among the fluxes of methane emission in various types of soils.Methane formation was observed in each type of air-dried soils stored for a long time after addition of water and incubation at 35℃. 相似文献
2.
可溶性有机物对土壤中绿麦隆吸附与解吸的影响 总被引：7，自引：0，他引：7
A batch equilibrium techniques was used to examine the effect of dissolved organic matter （DOM） extracted from both non-treated sludge （NTS） and heat-expanded sludge （HES） on the sorption and desorption of chlorotoluron （3-（3-chloro-p-tolyl）-1,1-dimethylurea） in two types of soils, a yellow fluvo-aquic and a red soil from China. Without DOM,sorption of chlorotoluron was significantly greater （P 〈 0.05） in the red soil than in the yellow fluvo-aquic soil. However,with DOM the effect was dependent on the soil type and nature of DOM. Chlorotoluron sorption was lower in the yellow fluvo-aquic soil than in the red soil, suggesting that with the same DOM levels the yellow fluvo-aquic soil had a lower sorption capacity for this herbicide. Application of DOM from both NTS and HES led to a general decrease in sorption to the soils and an increase in desorption from the soils. Desorption of chlorotoluron also significantly increased （P 〈 0.05） with an increase in the DOM concentration. Additionally, for sorption and desorption, at each DOM treatment level the NTS treatments were significantly lower （P 〈 0.05） than the HES treatments. This implied that non-treated sludge had a greater effect on the sorption and desorption of chlorotoluron than heat-expanded sludge. 相似文献
3.
The clay minerals of more than 200 soil samples collected from various sites of Fujian Province were studied by the X-ray diffraction method and transmission electron microscopy to study their distribution and evolution.Montmorillonite was found in coastal solonchak,paddy soils derived from marine deposit,lacustrine deposit and river deposit,and some lateritic red soil,red soil and yellow soil with a low weathering degree.Chlorite existed mainly in coastal solonchak and paddy soil developed from marine deposit.1.4nm intergradient mineral appeared frequently in yellow soil,red soil and lateritic red soil.The content of 1.4nm intergradient mineral increased with the decrease of weathering degree from lateritic red soil to red soil to yellow soil.Hydrous micas were more in coastal solonchak,paddy soils derived from marine deposit,lacustrine deposit and river deposit.and puple soil from purple shale than in other soils.Kaolinte was the most important clay mineral in the soils iun this province.The higher the soil weathering degree,the more the kaolinite existed.From yellow soil to red soil to lateritic red soil,kaolinite increased gradually,Kaolinite was the predominant clay mineral accompanied by few other minerals in typical lateritic red soil. Tubular halloysite was a widespread clay mineral in soils of Fujian Province with varying quantities.The soil derived from the paent rocks rich in feldspar contained more tubular halloysite.Spheroidal halloysite was found in a red soil and a paddy soil developed from olivine basalt gibbsite in the soils in this district was largely“primary gibbsite” which formed in the early weathering stage.Gibbsite decreased with the increase of weathering degree from yellow soil to red soil to lateritic red soil.Goethite also decreased in the same sequence while hematite increased. 相似文献
4.
土壤中氮磷钾肥转化中的交互作用: Ⅰ.土壤pH的动态变化 总被引：10，自引：0，他引：10
WANG Huo-Yan ZHOU Jian-Min CHEN Xaio-Qin LI Shou-Tian DU Chang-Wen DONG Cai-Xia 《土壤圈》2003,13(3):257-262
Dynamic changes of soil pH as influenced by ammonium sulfate (AS), monocalcium phosphate (MCP),potassium chloride (KCl) and their interaction in soils were evaluated in incubation experiments. Applyingthese fertilizers significantly reduced soil pH values in all cases and followed sequences of AS ＞ MCP ＞KCl, MCP ＞ KCl ＞ AS and KCl ＞ AS ＞ MCP for the paddy, calcareous and red soils, respectively. TheAS-induced reduction of pH in the three soils followed the sequence of red soil ＞ paddy soil ＞ calcareous soil,while in MCP and KCl systems the reduction of pH followed the sequences of calcareous soil ＞ paddy soil ＞red soil and red soil ＞ calcareous soil ＞ paddy soil, respectively. The interactions of the NPK fertilizers on pHwere significant. MCP plus KCl or MCP plus AS reduced pH values more than the fertilizers applied solelyin the paddy soil, but AS partly counteracted the effect of MCP on pH in the 1 d sample of the calcareoussoil. The effect of MCP on pH was trivial when MCP was applied in combination with KCl or AS in the redsoil. When applied in combination with AS, KCl did not affect soil pH initially, but suppressed the reductionof pH at the later incubation stage, which was related to inhibition of nitrification by KCl in the soils. 相似文献
5.
A laboratory-based aerobic incubation was conducted to investigate nitrogen(N) isotopic fractionation related to nitrification in five agricultural soils after application of ammonium sulfate((NH4)2SO4). The soil samples were collected from a subtropical barren land soil derived from granite(RGB),three subtropical upland soils derived from granite(RQU),Quaternary red earth(RGU),Quaternary Xiashu loess(YQU) and a temperate upland soil generated from alluvial deposit(FAU). The five soils varied in nitrification potential,being in the order of FAU YQU RGU RQU RGB. Significant N isotopic fractionation accompanied nitrification of NH+4. δ15N values of NH+4 increased with enhanced nitrification over time in the four upland soils with NH+4 addition,while those of NO-3 decreased consistently to the minimum and thereafter increased. δ15N values of NH+4 showed a significantly negative linear relationship with NH+4-N concentration,but a positive linear relationship with NO-3-N concentration. The apparent isotopic fractionation factor calculated based on the loss of NH+4 was 1.036 for RQU,1.022 for RGU,1.016 for YQU,and 1.020 for FAU,respectively. Zero- and first-order reaction kinetics seemed to have their limitations in describing the nitrification process affected by NH+4 input in the studied soils. In contrast,N kinetic isotope fractionation was closely related to the nitrifying activity,and might serve as an alternative tool for estimating the nitrification capacity of agricultural soils. 相似文献
6.
磷处理土壤中磷的释放动力学研究 总被引：3，自引：3，他引：3
Phosphate release from three selected soils after treatments of 1.6 and 2.4 mmol L^-1 P was investigated using sequential extractions and fitted using six kinetic models, including zero order （Z）, first order （F）, second order （S）,parabolic diffusion （PD）, two constant rate （TC）, and Elovich type （ET） equations. The results showed that the rate of P release was initially rapid and then gradually declined with time. Also, P release increased with added P. Total P release followed the order： paddy soil with 2.4 mmol L^-1 P 〉 red soil with 2.4 mmol L^-1 P 〉 paddy soil with 1.6 mmol L^-1 P〉 fluvo-aquic soil with 2.4 mmol L^-1 P 〉 fluvo-aquic with 1.6 mmol L^-1 P 〉 red soil with 1.6 mmol L^-1 P. For the two P treatments P release from the paddy soils in the first extraction was 44.3% and 45.6% of total released P, respectively,which were higher than those from red and fluvo-aquic soils. The ratio of P release at the end of release time was 14.0%and 13.1% in the paddy soil treated with 1.6 and 2.4 mmol L^-1 P, respectively, but only 5.1% and 9.2% in the red soil and 7.0% and 5.2% in the fluvo-aquic soil, respectively. Comparison of the coefficients of determination （R^2） indicated that ET, TC, and PD equations could describe the P release data better than Z, F, and S equations. 相似文献
7.
上海地区水稻土氮素矿化模拟 总被引：1，自引：0，他引：1
Three types of paddy soils, derived from granite, Quaternary red clay and basalt, respectively, were selected to study the effects of Fe and Mn in paddy soils on methane production and emission through pot and incubation experiments. The results indicated that the difference of Fe and Mn in paddy soils was one of the important factors causing obvious differences in methane emission from different soil types. Soil Fe and Mn affecting methane emission from the paddy soils was likely through affecting soil Eh and forming Fe and Mn plaques on rice roots. Different rates and valences of added Fe and Mn significantly affected methane production from paddy soils. Therefore, this study enhanced understanding of processes controlling methane emission from paddy soils and may help to improve modeling and estimating regional and global methane emission from paddy soils. 相似文献
8.
二(2-乙基己基)邻苯二甲酸酯降解菌的分离和鉴定及其在污染土壤生物修复中的作用 总被引：2，自引：0，他引：2
Di-（2-ethylhexyl） phthalate（DEHP） is a high-molecular-weight phthalate ester（PAE） that has been widely used in the manufacture of polyvinylchloride and contributes to environmental pollution.The objectives of the present study were to isolate a DEHP degrader that can utilize DEHP as a carbon source and to investigate its capacity to biodegrade DEHP in both liquid culture and soil.A bacterial strain WJ4 was isolated from an intensively managed vegetable soil,which was contaminated with PAEs.The strain WJ4 was affiliated to the genus Rhodococcus and was able to remove DEHP from soil effectively.A period of only 7 d was required to degrade about 96.4%of DEHP(200 mg L-1) in the liquid culture,and more than 55%of DEHP(1.0 g kg-1) in the artificially contaminated soil was removed within 21 d.Furthermore,Rhodococcus sp.strain WJ4 had a strong ability to degrade DEHP without additional nutrients in liquid minimal medium culture and DEHP-contaminated soil and to degrade the homologue of DEHP in both liquid culture and soil.Strain WJ4 represents a novel tool for removing PAEs from contaminated soils and it may have great potential for application in the remediation of environmental pollution by PAEs. 相似文献
9.
采用通气堆沤对石油烃污染土壤进行生物修复 总被引：20，自引：0，他引：20
Laboratory simulation studies and a composting pilot study were conducted to evaluate the capacity of three strains of fungi, indigenous fungus Fusarium sp. and Phanerochaete chrysosporium and Coriolus Versicolor, to remediate petroleum-contaminated soils. In laboratory, the fungi were inoculated into a liquidculture medium and the petroleum-contaminated soil samples for incubation of 40 and 50 days 5 respectively. In the 200-day pilot study, nutrient contents and moisture were adjusted and maintained under aerobiccondition in composting units using concrete container (118.5 cm × 65.5 cm × 12.5 cm) designed specially for this study. The laboratory simulation results showed that all the three fungi were effective in degrading petroleum in the liquid culture medium and in the soil. At the end of both the laboratory incubations, the degradation rates by Phanerochaete chrysosporium were the highest, reaching 66% after incubation in liquid culture for 50 days. This was further demonstrated in the composting pilot study where the degradation rate by P. chrysosporium reached 79% within 200 days, higher than those of the other two fungi (53.1% and 46.1%), indicating that P. chrysosporium was the best fungus for bioremediation of soil contaminated with petroleum. Further research is required to increase degradation rate. 相似文献
10.
两种农田土壤中的氨氧化细菌和氨氧化古菌对硝化抑制剂DCD和DMPP的响应-盆栽试验 总被引：4，自引：0，他引：4
Taking two important agricultural soils with different pH, brown soil （Hap-Udic Luvisol） and cinnamon soil （Hap-Ustic Luvisol）, from Northeast China, a pot culture experiment with spring maize （Zea mays L.） was conducted to study the dynamic changes in the abundance and diversity of soil ammonia-oxidizing bacteria （AOB） and ammonia-oxidizing archaea （AOA） populations during maize growth period in response to the additions of nitrification inhibitors dicyandiamide （DCD） and 3,4-dimethylpyrazole phosphate （DMPP） by the methods of real-time polymerase chain reaction （PCR） assay, PCR-denaturing gradient gel electrophoresis （DGGE）, and construction of clone library targeting the amoA gene. Four treatments were established, i.e., no urea （control）, urea, urea plus DCD, and urea plus DMPP. Both DCD and DMPP inhibited growth of AOB significantly, compared to applying urea alone. Soil bacterial amoA gene copies had a significant positive linear correlation with soil nitrate content, but soil archaeal amoA gene copies did not. In both soils, all AOB sequences fell within Nitrosospira or Nitrosospira-like groups, and all AOA sequences belonged to group 1.1b crenaxchaea. With the application of DCD or DMPP, community composition of AOB and AOA in the two soils had less change except that the AOB community composition in Hap-Udic Luvisol changed at the last two growth stages of maize under the application of DCD. AOB rather than AOA likely dominated soil ammonia oxidation in these two agricultural soils. 相似文献
11.
Soil nitrification rate is very different among soil types, as a result of differences in physical and chemical properties. Little is known about the composition of the nitrifying bacteria community. In this investigation, three soils (fluvo-aquic soil, permeable paddy soil and red earth) from different geo-ecological regions in China were characterized for their nitrification activities and their nitrifying bacteria communities determined either by molecular approaches or by conventional culture methods. A 28-day long-term soil incubation showed that the maximum nitrification potential was found in the fluvo-aquic soil with almost 100% of inorganic N present as NO3–-N, while the minimum nitrification potential was in red earth with only a 4.9% conversion rate from ammonium into nitrate. There was no relationship between nitrification potential and numbers of nitrifiers in the soil. The conventional most probable number (MPN) method could enumerate ammonia oxidizers, but failed in enumerating nitrite oxidizers. Therefore, we used an MPN-PCR procedure which gave a convincing nitrite oxidizer count result, instead of MPN-diphylamine. Soils were characterized by denaturing gradient gel electrophoresis (DGGE) of DNA extracted from soils and amplified using a primer specific for the 16S rRNA gene and/or for the amoA gene. The DGGE columns of the three soils differed from each other. There were two similar bands present in DGGE columns of the fluvo-aquic and permeable paddy soils, but no similar band was found in DGGE columns of the red earth. The sequence of amoA indicated that all ammonia oxidizers in these soils were grouped into Nitrosospira clusters 1 and 3, and each soil had a common band similar to the other soils and a special band which differed from the other soils. 相似文献
12.
Increasing lines of evidence have suggested the functional importance of ammonia-oxidizing archaea (AOA) rather than bacteria (AOB) for nitrification in upland soils with low pH. However, it remains unclear whether niche specialization of AOA and AOB occurs in rice paddy wetlands constrained by oxygen availability. Using DNA-based stable isotope probing, we conclude that AOA dominated nitrification activity in acidic paddy soils (pH 5.6) while AOB dominated in alkaline soils (pH 8.2). Nitrification activity was stimulated by urea fertilization and accompanied by a significant increase of AOA in acid soils and AOB in alkaline soils. DNA-based stable isotope probing indicated significant assimilation of 13CO2 for AOA only in acidic paddy soil, while AOB was the solely responsible for ammonia oxidation in the alkaline paddy soil. Phylogenetic analysis further indicated that AOA members within the soil group 1.1b lineage dominated nitrification in acid soils. Ammonia oxidation in the alkaline soil was catalyzed by Nitrosospira cluster 3-like AOB, suggesting that the physiological diversity of AOA is more complicated than previously thought, and soil pH plays important roles in shaping the community structures of ammonia oxidizers in paddy field. 相似文献
13.
水稻生育期内红壤稻田氨氧化微生物数量和硝化势的变化 总被引：1，自引：1，他引：0
利用荧光定量PCR(Real-timePCR)技术,通过特异引物检测amoA基因拷贝数分析了水稻不同生育期红壤稻田土壤中氨氧化细菌(Ammonia oxidizing bacteria,AOB)和氨氧化古菌(Ammonia oxidizing archaea,AOA)的数量变化,并测定了土壤潜在硝化势。结果显示:红壤稻田土壤中AOA数量显著高于AOB,二者比例在1.6～120.7之间;红壤稻田根层土中AOA数量显著高于表土,随水稻生长根层和表土中AOA数量均逐渐增加,且根层土中增加幅度更大;在水稻生长前期表土中AOB数量较多,孕穗期后根层土中AOB数量显著增加且高于表土。水稻生长期内土壤潜在硝化势也具有逐渐增加趋势,且根层土潜在硝化势增加幅度更大。根层土中潜在硝化势与AOB和AOA数量均呈显著正相关,而表土中潜在硝化势只与AOA数量存在显著正相关。研究表明,红壤稻田土壤中AOA数量更为丰富,且与硝化作用的关联程度更为密切,证实了氨氧化微生物在红壤稻田土壤微生物组成及其生态系统功能中的重要性。 相似文献
14.
选择初始pH相近的两个酸性土壤(JX-3和JX-7)样品进行培养试验,探讨了氨氧化古菌(ammonia-oxidizing archaea,AOA)和氨氧化细菌(ammonia-oxidizing bacteria,AOB)在酸性土壤硝化过程中所发挥的作用。结果显示,经过50 d的培养,JX-7样品硝化速率显著高于JX-3,且明显降低土壤pH。培养后,两个土壤样品AOB丰度均增加,但样品间没有显著差异;JX-7土壤AOA丰度显著增加,而JX-3无显著变化。两个土壤样品AOA群落组成本身存在分异,但对于同一样品培养前后均无显著分异;AOB群落组成在两土壤间没有分异,但培养前后分别有分异。培养后,JX-7样品中AOA优势属Nitrososphaera和某些未知微生物的个别OTUs绝对丰度显著增加,而两样品AOB中Nitrosospira属的一些OTUs的绝对丰度均显著增加。因此,所研究的酸性土壤样品中AOA是硝化作用的主要贡献者,而且AOA主要通过提高Nitrososphaera属中个别OTUs的丰度,而不是整个群落来调控硝化作用。 相似文献
15.
Abundance and community structure of ammonia-oxidizing archaea and bacteria in an acid paddy soil 总被引：1，自引：0，他引：1
Xin Chen Li-Mei Zhang Ju-Pei Shen Wen-Xue Wei Ji-Zheng He 《Biology and Fertility of Soils》2011,47(3):323-331
Nitrification is essential to the nitrogen cycle in paddy soils. However, it is still not clear which group of ammonia-oxidizing
microorganisms plays more important roles in nitrification in the paddy soils. The changes in the abundance and composition
of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) were investigated by real-time PCR, terminal restriction
fragment length polymorphism, and clone library approaches in an acid red paddy soil subjected to long-term fertilization
treatments, including treatment without fertilizers (CT); chemical fertilizer nitrogen (N); N and potassium (NK); N and phosphorus
(NP); N, P, and K (NPK); and NPK plus recycled crop residues (NPK+C). The AOA population size in NPK+C was higher than those
in CT, while minor changes in AOB population sizes were detected among the treatments. There were also some changes in AOA
community composition responding to different fertilization treatments. Still few differences were detected in AOB community
composition among the treatments. Phylogenetic analysis showed that the AOA sequences fell into two main clusters: cluster
A and cluster soil/sediment. The AOB composition in this paddy soil was dominated by Nitrosospira cluster 12. These results suggested that the AOA were more sensitive than AOB to different fertilization treatments in the
acid red paddy soil. 相似文献
16.
石灰和双氰胺对红壤酸化和硝化作用的影响及其机制 总被引：4，自引：1，他引：3
施用石灰是改良酸性土壤的重要措施,但其对土壤硝化作用的增强不仅加速土壤酸化,也增加硝态氮流失风险。传统的硝化抑制剂双氰胺(Dicyandiamide,DCD)能否在石灰改变pH的条件下始终有效抑制硝化是当前红壤区生产中亟需解决的问题。采用短期土壤培养试验,探讨了不同用量石灰与DCD配合施用对土壤酸化和硝化作用的影响及其机制。结果表明:施用一定量的石灰(≤4 g·kg–1)显著提高土壤pH,通过促进氨氧化细菌的生长以促进硝化作用。在不同pH条件下,DCD对红壤硝化过程均有显著抑制效果。在较高pH(pH 7.0~7.8)条件下,DCD主要通过降低氨氧化细菌的丰度以抑制硝化,而在低pH(pH<6.0)条件下,DCD对氨氧化古菌和氨氧化细菌的丰度均有抑制作用。此外,DCD通过抑制土壤硝化,显著提高了土壤pH。上述结果表明,适宜量(2~4 g·kg–1)的石灰和DCD结合施用不仅能够减缓红壤酸化,而且能够抑制硝化作用,降低硝态氮的潜在环境风险。 相似文献
17.
18.
几种吡啶类化合物对土壤硝化的抑制作用比较 总被引：4，自引：1，他引：3
为了探明吡啶类化合物对土壤硝化作用的抑制效应,采用室内微宇宙试验,研究了2-氯-6(三氯甲基)硫酸盐、2-氯-6(三氯甲基)盐酸盐、吡啶混合物和吡啶X类化合物对潮土、红壤和水稻土中铵态氮硝化的抑制作用。结果表明,在35 d培养期内,吡啶类化合物处理土壤硝态氮含量明显低于对照(未添加吡啶类化合物),吡啶类化合物对土壤中铵态氮的硝化抑制率介于2.91%~91.92%,抑制强度先逐渐升高后降低,在培养21 d时抑制强度达到峰值。不同类型吡啶类化合物对土壤中铵态氮的硝化抑制效果存在差异,吡啶盐酸盐类化合物优于其他几类化合物;吡啶类化合物对土壤中铵态氮的硝化抑制作用与土壤类型有关,对3种土壤中铵态氮的硝化抑制作用表现为潮土>水稻土>红壤。就同一土壤而言,硝化抑制强度随着吡啶类化合物用量的增加而增加。 相似文献
19.
为探究铁氧化物对土壤硝化动力学的影响,以全铁含量低的酸性潮土(pH4.9)和中性潮土(pH7.2)为研究对象,通过7d的室内恒温(28℃)培养,研究了不同pH土壤在添加0(对照),0.5%,1%,3%,5%,10%(重量比)铁氧化物后的硝化动力学过程。结果表明:铁氧化物加入量超过3%,则改变中性潮土的硝化动力学过程由一级变为零级模型。不同含量铁氧化物加入后,酸性潮土的硝化过程均符合一级动力学模型。加铁处理的酸性潮土,其净矿化速率均显著高于不加铁处理。加铁量为10%处理的净矿化速率为4.12mg/(kg·d),是不加铁处理的7.82倍。随着铁氧化物加入量的增加,酸性潮土净硝化速率显著升高而中性潮土净硝化速率却显著下降。酸性潮土中铁氧化物加入量超过3%的处理,其净硝化速率极显著高于加铁量小于3%的处理。总之,铁氧化物的加入显著促进酸性潮土的净硝化速率,对中性潮土的净硝化速率却有显著抑制作用,并且加入量越大对2种土壤的作用效果越显著。3%的铁氧化物加入量是显著影响酸性潮土和中性潮土硝化作用的临界值。 相似文献
20.