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1.
亚热带土壤不同矿物组分中铬的吸附   总被引:1,自引:0,他引:1  
Safe application of chromium (Cr)-containing organic industrial wastes to soil requires considering the ability of the soil to adsorb Cr.In this study,the maximum Cr adsorption capacity was assessed for the bulk samples and their clay and iron-free clay fractions of four subtropical soils differing in mineralogy.To this end,the samples were supplied with Cr(Ⅲ) nitrate solutions at pH 4.5 or 5.5.The results of Cr(Ⅲ) adsorption fitted to a Freundlich equation and the adsorption capacity was positively correlated with soil organic matter and iron oxide contents.The clay fractions adsorbed more Cr per unit mass than the bulk soils and the iron-free clay fractions.The Cr(Ⅲ) adsorption capacity increased with increasing soil pH due to more charges on adsorbing surfaces.Our results suggest that the soils rich in organic matter and iron oxides and having a pH above 4.5 are suitable for application of Cr(Ⅲ)-loaded industrial wastes.  相似文献   

2.
江苏省土壤有机碳空间差异性以及影响因素研究   总被引:2,自引:0,他引:2  
Soil organic carbon (SOC) plays a key role in the global carbon cycle.In this study,we used statistical and geostatistical methods to characterize and compare the spatial heterogeneity of SOC in soils of Jiangsu Province,China,and investigate the factors that influence it,such as topography,soil type,and land use.Our study was based on 24 186 soil samples obtained from the surface soil layer (0-0.2 m) and covering the entire area of the province.Interpolated values of SOC density in the surface layer,obtained by kriging based on a spherical model,ranged between 3.25 and 32.43 kg m 3.The highest SOC densities tended to occur in the Taihu Plain,Lixia River Plain,along the Yangtze River,and in high-elevation hilly areas such as those in northern and southwest Jiangsu,while the lowest values were found in the coastal plain.Elevation,slope,soil type,and land use type significantly affected SOC densities.Steeper slope tended to result in SOC decline.Correlation between elevation and SOC densities was positive in the hill areas but negative in the low plain areas,probably due to the effect of different land cover types,temperature,and soil fertility.High SOC densities were usually found in limestone and paddy soils and low densities in coastal saline soils and alluvial soils,indicating that high clay and silt contents in the soils could lead to an increase,and high sand content to a decrease in the accumulation of SOC.SOC densities were sensitive to land use and usually increased in towns,woodland,paddy land,and shallow water areas,which were strongly affected by industrial and human activities,covered with highly productive vegetation,or subject to long-term use of organic fertilizers or flooding conditions.  相似文献   

3.
城郊土壤不透水表面有土壤机碳转化及其相关性质的研究   总被引:2,自引:0,他引:2  
Installation of impervious surface in urban area prevents the exchange of material and energy between soil and other environmental counterparts, thereby resulting in negative effects on soil function and urban environment. Soil samples were collected at 0-20 cm depth in Nanjing City, China, in which seven sites were selected for urban open soils, and fourteen sites with similar parent material were selected for the impervious-covered soils, to examine the effect of impervious surface on soil properties and microbial activities, and to determine the most important soil properties associated with soil organic carbon (SOC) transformation in the urban soils covered by impervious surfaces. Soil organic carbon and water-soluble organic carbon (WSOC) concentrations, potential carbon (C) and nitrogen (N) mineralization rates, basal respiration, and physicochemical properties with respect to C transformation were measured. Installation of impervious surface severely affected soil physicochemical properties and microbial activities, e.g., it significantly decreased total N contents, potential C mineralization and basal respiration rate (P 〈 0.01), while increased pH, clay and Olsen-P concentrations. Soil organic carbon in the sealed soils at 0-20 cm was 2.35 kg m-2, which was significantly lower than the value of 4.52 kg m-2 in the open soils (P 〈 0.05). Canonical correlation analysis showed WSOC played a major role in determining SOC transformation in the impervious-covered soil, and it was highly correlated with total N content and potential C mineralization rate. These findings demonstrate that installation of impervious surface in urban area, which will result in decreases of SOC and total N concentrations and soil microbial activities, has certain negative consequences for soil fertility and long-term storage of SOC.  相似文献   

4.
土壤有机碳活性组分沿中国长白山海拔坡度的分布情况   总被引:4,自引:0,他引:4  
Understanding the responses of soil organic carbon(SOC) fractions to altitudinal gradient variation is important for understanding changes in the carbon balance of forest ecosystems.In our study the SOC and its fractions of readily oxidizable carbon(ROC),water-soluble carbon(WSC) and microbial biomass carbon(MBC) in the soil organic and mineral horizons were investigated for four typical forest types,including mixed coniferous broad-leaved forest(MCB),dark coniferous spruce-fir forest(DCSF),dark coniferous spruce forest(DCS),and Ermans birch forest(EB),along an altitudinal gradient in the Changbai Mountain Nature Reserve in Northeast China.The results showed that there was no obvious altitudinal pattern in the SOC.Similar variation trends of SOC with altitude were observed between the organic and mineral horizons.Significant differences in the contents of SOC,WSC,MBC and ROC were found among the four forest types and between horizons.The contents of ROC in the mineral horizon,WSC in the organic horizon and MBC in both horizons in the MCB and EB forests were significantly greater than those in either DCSF or DCS forest.The proportion of soil WSC to SOC was the lowest among the three main fractions.The contents of WSC,MBC and ROC were significantly correlated(P < 0.05) with SOC content.It can be concluded that vegetation types and climate were crucial factors in regulating the distribution of soil organic carbon fractions in Changbai Mountain.  相似文献   

5.
Extensive use of chemical fertilizers in agriculture can induce high concentration of ammonium nitrogen(NH4+-N) in soil. Desorption and leaching of NH4+-N has led to pollution of natural waters. The adsorption of NH4+-N in soil plays an important role in the fate of the NH4+-N. Understanding the adsorption characteristics of NH4+-N is necessary to ascertain and predict its fate in the soil-water environment, and pedotransfer functions(PTFs) could be a convenient method for quantification of the adsorption parameters. Ammonium nitrogen adsorption capacity, isotherms, and their influencing factors were investigated for various soils in an irrigation district of the North China Plain. Fourteen agricultural soils with three types of texture(silt, silty loam, and sandy loam) were collected from topsoil to perform batch experiments. Silt and silty loam soils had higher NH4+-N adsorption capacity than sandy loam soils.Clay and silt contents significantly affected the adsorption capacity of NH4+-N in the different soils. The adsorption isotherms of NH4+-N in the 14 soils fit well using the Freundlich, Langmuir, and Temkin models. The models’ adsorption parameters were significantly related to soil properties including clay,silt, and organic carbon contents and Fe2+ and Fe3+ ion concentrations in the groundwater. The PTFs that relate soil and groundwater properties to soil NH4+-N adsorption isotherms were derived using multiple regressions where the coefficients were predicted using the Bayesian method. The PTFs of the three adsorption isotherm models were successfully verified and could be useful tools to help predict NH4+-N adsorption at a regional scale in irrigation districts.  相似文献   

6.
Changes in soil organic carbon (SOC) in agricultural soils influence soil quality and greenhouse gas concentrations in the atmosphere. Dry farmland covers more than 70% of the whole cropland area in China and plays an important role in mitigating carbon dioxide (CO2) emissions. In this study, 4109 dry farmland soil polygons were extracted using spatial overlay analysis of the soil layer (1:500000) and the land use layer (1:500000) to support Century model simulations of SOC dynamics for dry farmland in Anhui Province, East China from 1980 to 2008. Considering two field-validation sites, the Century model performed relatively well in modeling SOC dynamics for dry farmland in the province. The simulated results showed that the area-weighted mean soil organic carbon density (SOCD) of dry farmland increased from 18.77 Mg C ha1 in 1980 to 23.99 Mg C ha1 in 2008 with an average sequestration rate of 0.18 Mg C ha1 year?1. Approximately 94.9% of the total dry farmland area sequestered carbon while 5.1% had carbon lost. Over the past 29 years, the net SOC gain in dry farmland soils of the province was 19.37 Tg, with an average sequestration rate of 0.67 Tg C year1. Augmentation of SOC was primarily due to increased consumption of nitrogen fertilizer and farmyard manure. Moreover, SOC dynamics were highly differentiated among dry farmland soil groups. The integration of the Century model with a fine-scale soil database approach could be conveniently utilized as a tool for the accurate simulation of SOC dynamics at the regional scale.  相似文献   

7.
Equilibrium and kinetic studies have been made on the adsorption of acrylonitrile(CH2=CHCN) on three soils and four minerals from aqueous solutions.It was shown that the organic matter was the major factor affecting the adsorption process in the soils.The conformity of the equilibrium data to linear type(one soil) and Langmuir type(two soils) isotherms indicated that different mechanisms were involved in the adsorption.This behavior appears bo be related to the hydrophobicity of soil organic matter due to their composition and E4/E6 ratio of humic acids.The adsorption kinetics were also different among the soils,indicating the difference in porosity of organic matter among the soils,and the kinetics strongly affected the adsorption capacity of soils for acrylonitrile.Acrylonitrile was slightly adsorbed from aqueous solutions on pyrophyllite with electrically neutral and hydrophobic nature,and practically not on montmorillonite and kaolinite saturated with Ca.However,much higher adsorption occurred on the zeolitized coal ash,probably caused by high organic carbon content(107g/kg).  相似文献   

8.
中国农田土壤有机碳贮存的空间特征   总被引:2,自引:0,他引:2  
The soil organic carbon (SOC) pool is the largest component of terrestrial carbon pools. With the construction of a geographically referenced database taken from the second national general soil survey materials and based on 1546 typical cropland soil profiles, the paddy field and dryland SOC storage among quantified to characterize the spatial pattern of cropland SOC storage in China regions of China were systematically to examine the relationship between mean annual temperature, precipitation, soil texture features arid SOC content. In all regions, paddy soils had higher SOC storage than dryland soils, and cropland SOC content was the highest in Southwest China. Climate controlled the spatial distribution of SOC in both paddy and dryland soils, with SOC storage increasing with increasing precipitation and decreasing with increasing temperature.  相似文献   

9.
Soil organic carbon(SOC) is an important component of farming systems and global carbon cycle. Accurately estimating SOC stock is of great importance for assessing soil productivity and modeling global climate change. A newly built 1:50 000 soil database of Zhejiang Province containing 2 154 geo-referenced soil profiles and a pedological professional knowledge-based(PKB) method were used to estimate SOC stock up to a depth of 100 cm for the Province. The spatial patterns of SOC stocks stratified by soil types,watershed(buffer analysis), topographical factors, and land use types were identified. Results showed that the soils in Zhejiang covered an area of 100 740 km2 with a total SOC stock of 831.49 × 106 t and a mean SOC density of 8.25 kg m-2, excluding water and urban areas. In terms of soil types, red soils had the highest SOC stock(259.10 × 106t), whereas mountain meadow soils contained the lowest(0.15 × 106t). In terms of SOC densities, the lowest value(5.11 kg m-2) was found in skel soils, whereas the highest value(45.30 kg m-2) was observed in mountain meadow soils. Yellow soils, as a dominant soil group, determined the SOC densities of different buffer zones in Qiantang River watershed because of their large area percentage and wide variation of SOC density values.The area percentages of various soil groups significantly varied with increasing elevation or slope when overlaid with digital elevation model data, thus influencing the SOC densities. The highest SOC density was observed under grassland, whereas the lowest SOC density was identified under unutilized land. The map of SOC density(0–100 cm depth) and the spatial patterns of SOC stocks in the Province would be helpful for relevant agencies and communities in Zhejiang Province, China.  相似文献   

10.
长期免耕对东北地区玉米田土壤有机碳组分的影响   总被引:6,自引:0,他引:6  
Increasing evidence has shown that conservation tillage is an effective agricultural practice to increase carbon (C) sequestration in soils. In order to understand the mechanisms underlying the responses of soil organic carbon (SOC) to tillage regimes, physical fractionation techniques were employed to evaluate the effect of long-term no-tillage (NT) on soil aggregation and SOC fractions. Results showed that NT increased the concentration of total SOC by 18.1% compared with conventional tillage (CT) under a long-term maize (Zea mays L.) cropping system in Northeast China. The proportion of soil large macroaggregates ( 2000 μm) was higher in NT than that in CT, while small macroaggregates (250-2000 μm) showed an opposite trend. Therefore, the total proportion of macroaggregates ( 2000 and 250-2000 μm) was not affected by tillage management. However, C concentrations of macroaggregates on a whole soil basis were higher under NT relative to CT, indicating that both the amount of aggregation and aggregate turnover affected C stabilization. Carbon concentrations of intra-aggregate particulate organic matter associated with microaggregates (iPOM m) and microaggregates occluded within macroaggregates (iPOM mM) in NT were 1.6 and 1.8 times greater than those in CT, respectively. Carbon proportions of iPOM m and iPOM mM in the total SOC increased from 5.4% and 6.3% in CT to 7.2% and 9.7% in NT, respectively. Furthermore, the difference in the microaggregate protected C (i.e., iPOM m and iPOM mM) between NT and CT could explain 45.4% of the difference in the whole SOC. The above results indicate that NT stimulates C accumulation within microaggregates which then are further acted upon in the soil to form macroaggregates. The shift of SOC within microaggregates is beneficial for long-term C sequestration in soil. We also corroborate that the microaggregate protected C is useful as a pool for assessing the impact of tillage management on SOC storage.  相似文献   

11.
荒漠草原沙漠化对土壤无机碳和有机碳的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
以空间代替时间的方法,通过对宁夏荒漠草原不同沙漠化阶段土壤有机碳(SOC)和无机碳(SIC)的研究,探讨荒漠草原沙漠化对土壤SIC、SOC及不同粒径组分土壤SIC、SOC分布特征的影响。结果表明:(1)随着荒漠草原沙漠化程度的加剧,0—10cm土层各粒径组分土壤SIC和SOC含量呈下降趋势。半固定沙地和流动沙地各粒径组分土壤SIC含量均表现为黏粉粒无机碳(CSIC)细砂粒无机碳(FIC)粗砂粒无机碳(CIC),而SOC含量均表现为细砂粒有机碳(FOC)粗砂粒有机碳(COC)黏粉粒有机碳(CSOC)。(2)随着荒漠草原沙漠化程度的加剧,0—30cm土层土壤无机碳(SICD)、土壤有机碳(SOCD)和土壤总碳(STCD)密度均表现为荒漠草原固定沙地半固定沙地流动沙地。固定沙地、半固定沙地和流动沙地土壤SOCD、SICD分别比荒漠草原降低了18.5%,57.7%,60.5%和6.7%,35.9%,47.0%。(3)0—10cm土层各粒径组分土壤SOC和SIC含量、全土SOC含量与0—30cm土层SOC和SIC均呈显著正相关关系,其中土壤粗砂粒有机碳和粗砂粒无机碳对SOC影响最大,而土壤黏粉粒有机碳和黏粉粒无机碳与全土SIC含量呈显著负相关关系。因此,沙漠化防治对于减少荒漠草原土壤碳损失极为重要。  相似文献   

12.
淤地坝作为黄土高原重要的碳储库,其深层土壤有机碳稳定性在很大程度上影响坝地土壤储碳能力和碳排放。以黄土丘陵区不同利用年限的坝地为对象,从坝地剖面土壤有机碳含量及其组分入手,研究不同利用年限、不同沉积深度下,土壤有机碳含量及其稳定性的变化特征和影响因素。结果表明:(1)坝地深层土壤有机碳(SOC)含量低于该区坡耕地表层土壤有机碳含量,并未呈现明显的有机碳富集现象。随利用年限增加,坝地SOC含量呈增加趋势。(2)不同利用年限坝地的SOC、易氧化碳(EOC)、微生物量碳(MBC)、水溶性碳(DOC)含量呈现出明显的表聚现象。MBC、DOC和EOC含量在土壤0—60 cm内较高。(3)相较于坝地浅层土壤而言,坝地深层土壤有机碳具有较高的稳定性,长期耕作会降低坝地深层土壤有机碳稳定性。(4)坝地浅层和深层土壤有机碳稳定性变化的主导因素不同。浅层土壤有机碳稳定性主要受土层深度、有机碳含量和黏粒含量的影响,分别能解释其变异的50.4%,19.6%和11.8%;深层土壤有机碳稳定性主要受有机碳含量、土壤含水量和利用年限的影响,分别能解释其变异的38.9%,33.9%和11.8%。  相似文献   

13.
张宇婕  于亚军 《土壤》2019,51(4):732-738
土壤有机碳含量是土壤肥力状况的重要标志之一,其活性组分对田间管理措施反映敏感。因此,分析煤矸山复垦重构土壤有机碳含量及其组分差异对于揭示土壤碳库变化、指导复垦地田间管理措施的实施有重要意义。本研究以山西省霍州曹村煤矸山复垦后5a(R-5a)、7a(R-7a)和9a(R-9a)的果园为对象,通过与当地原地貌果园(CK)对比,分析了3种复垦样地土壤总有机碳(TOC)及其组分可溶性有机碳(DOC)、微生物生物量碳(MBC)、轻组有机碳(LFOC)和重组有机碳(HFOC)的差异,以及与土壤环境因子间的关系。结果表明:①随复垦年限的增加,3种复垦样地土壤TOC、LFOC和HFOC含量均呈先增后减趋势,DOC含量呈增加趋势,MBC含量呈先减后增趋势;但与CK相比,3种复垦样地土壤TOC、DOC、MBC、LFOC和HFOC含量均明显偏低。②DOC/TOC和MBC/TOC在R-7a样地中最低,LFOC/TOC随复垦年限的增加呈增加趋势,HFOC/TOC呈减少趋势,表明土壤中更多的有机碳从稳定态转变为活性态。③土壤全氮、全磷、碱解氮、碳氮比、黏粒含量、pH和含水量均不同程度影响有机碳含量,其中全氮、全磷、黏粒含量和土壤pH为关键因子。  相似文献   

14.
江晶  武均  张仁陟  董博  蔡立群 《水土保持学报》2019,33(3):215-220,227
为探明碳氮添加4年后,土壤全氮、有机碳及其组分(可溶性有机碳、微生物量碳、轻组和重组有机碳)的变化特征,依托布设于甘肃省定西市安定区李家堡镇的不同碳源配施氮素田间定位试验,涉及秸秆、生物质炭、氮素3个因素,秸秆设置为不施、施用秸秆2水平;生物质炭为不施和施用生物质炭2个水平;氮素设置为不施氮、施纯氮50 kg/hm~2、施纯氮100 kg/hm~2 3个水平,共9个处理。结果表明:不同处理下土壤全氮、有机碳及其组分的含量均随土层的加深而降低。添加生物质炭对土壤全氮、有机碳及其组分均具有不同程度的提升效应。添加秸秆对土壤全氮、有机碳和可溶性有机碳、微生物量碳、轻组有机碳均具有显著提升效应,仅在0—5 cm土层对重组有机碳有显著提高。添加氮素可显著提升土壤全氮、有机碳和可溶性有机碳、微生物量碳、轻组有机碳含量。较其他处理,添加生物质炭对土壤全氮、有机碳和重组有机碳的提升效应最高,添加秸秆对可溶性有机碳、微生物量碳、轻组有机碳的提升效果最优。从提升土壤质量的角度出发,推荐秸秆配施氮素模式,该模式下土壤碳素有效性高、易于被微生物利用,有利于作物生长。从提高土壤固碳角度考虑,推荐生物质炭配施氮素模式,该模式有利于碳的封存。  相似文献   

15.
长期施肥下红壤有机碳及其颗粒组分对不同施肥模式的响应   总被引:15,自引:3,他引:12  
采集不同施肥24年的红壤,采用物理分组的方法,观测了长期不同施肥下红壤有机碳及其组分变化,并结合历史资料分析了不同施肥模式对红壤有机碳及其颗粒组分的影响。结果表明,化肥配施有机肥(NPKM)处理下红壤总有机碳含量(10.33 g/kg),砂粒(2000~53 m)、细粉粒(5~2 m)和粘粒(2 m)组分中的有机碳含量显著高于其他处理。与不施肥(CK)相比,施用化肥(NPK、2NPK)和有机肥(NPKM、M)显著地提高了红壤有机碳在砂粒和粘粒中的分配比例,而降低了其在粗粉粒和细粉粒的分配比例。施化肥(NPK、2NPK)、单施有机肥(M)、化肥配施有机肥(NPKM)处理,土壤有机碳的平均固定速率分别为0.05 t/(hm2?a)、0.18 t/(hm2?a)、0.26 t/(hm2?a)。相关分析表明,不同施肥模式下红壤有机碳的固定量与碳投入量之间存在着极显著的线性相关关系(R2=0.909, P0.01),土壤的固碳效率为8.1%;随着碳投入的增加,粗粉粒和细粉粒有机碳储量逐渐下降,而砂粒和粘粒中碳储量逐渐增加,并且粘粒增加速率要远远高于砂粒。以上结果说明,红壤中有机碳还没有达到饱和,还具有一定的固碳潜力,增加的有机碳主要固持在粘粒中,粘粒是红壤有机碳的主要固持组分。  相似文献   

16.
The aim of this study was to determine the effect of land‐use and forest cover depletion on the distribution of soil organic carbon (SOC) within particle‐size fractions in a volcanic soil. Emphasis was given to the thermal properties of soils. Six representative sites in Mexico were selected in an area dominated by Andosols: a grassland site, four forested sites with different levels of degradation and an agricultural site. Soils were fractionated using ultrasonic energy until complete dispersion was achieved. The particle‐size fractions were coarse sand, fine sand, silt, clay and particulate organic matter from the coarse sand sized fraction (POM‐CS) and fine sand (POM‐FS). Soil organic carbon decreased by 70% after forest conversion to cropland and long‐term cultivation; forest cover loss resulted in a decrease in SOC of up to 60%. The grassland soil contained 45% more SOC than the cropland one. Soil organic carbon was mainly associated with the silt‐size fraction; the most sensitive fractions to land‐use change and forest cover depletion were POM followed by SOC associated with the silt and clay‐sized fractions. Particulate organic matter can be used as an early indicator of SOC loss. The C lost from the clay and silt‐sized fractions was thermally labile; therefore, the SOC stored in the more degraded forest soils was more recalcitrant (thermally resistant). Only the transformation of forest to agricultural land produced a similar loss of thermally stable C associated with the silt‐sized fraction.  相似文献   

17.
汤松波  习丹  任文丹  旷远文 《土壤》2018,50(1):122-130
不同植被类型下土壤有机碳(SOC)储量和动态变化是全球变化研究的热点之一。对南亚热带鹤山6种不同植被类型(灌草、马尾松林、桉树林、乡土树林、马占相思林、季风常绿阔叶林)SOC干湿季、空间(0~10,10~20,20~40 cm)变化特征、土壤惰性指数及其与土壤有效氮(TAN)的关系研究表明:(1)6种植被中,干季SOC含量显著高于湿季,SOC含量随土层深度降低,马占相思林SOC含量最高,马尾松林和灌草最低;(2)6种植被SOC储量在0~10 cm土层所占比例最高,占0~40 cm土层SOC含量40%以上;(3)土壤惰性指数随土壤深度增加而下降,常绿阔叶林、乡土树林和马占相思林烷基碳和ROC惰性指数高于桉树林和马尾松林,揭示这3种植被SOC具有更高稳定性;(4)SOC与土壤TAN含量呈显著正相关。结果揭示,在植被恢复过程中,选择豆科植物,辅以乡土树种营造常绿阔叶林,有利于提高森林潜在碳汇功能。  相似文献   

18.
大量研究证明稻田土壤比旱地土壤更具固碳潜力,但至今对稻田土壤固碳机制的认识尚不甚清楚。本研究于2007年利用两个开垦年代相似,近20多年分别一直种植双季稻和双季玉米的长期定位试验,来比较不同种植模式下土壤有机碳及其组分的差异。结果表明,水田土壤总有机碳和总氮的浓度分别是旱地的2.2倍和2.5倍。与试验前相比,水稻种植显著提高了土壤有机碳的含量,增幅达到30.8%,而旱地的前后差异不显著。在所有团聚体粒径水平上,水田有机碳的浓度均显著高于旱地。其中53~250μm微团聚体相差最大,水田是旱地的近3倍。水田微团聚体保护碳(iPOM_m)在土壤中的浓度是旱地的4.2倍,微团聚体保护碳在总有机碳中的比重也显著高于旱地,达到25.5%,是旱地的2倍。水田和旱地iPOM_m组分碳的差异能够解释其总有机碳差异的42.8%。上述结果可以增强我们对稻田土壤固碳机制的了解,为稻田土壤碳管理提供理论依据。  相似文献   

19.
长白山不同林型土壤有机碳特征   总被引:2,自引:1,他引:1       下载免费PDF全文
采用野外采样与室内分析相结合的方法,研究了长白山北坡6种不同林型(阔叶林、针叶林、云冷杉、岳桦林、岳桦-苔原、高山苔原)土壤有机碳及其组分的含量,分析了土壤有机碳分布与铁铝氧化物和黏粒矿物组成之间的关系。结果表明:不同林型之间,阔叶林土壤的有机碳、胡敏素碳、颗粒有机碳、2~0.25 mm大团聚体碳和0.25~0.053 mm微团聚体碳含量最高,云冷杉土壤的易氧化碳含量最高而水溶性有机碳、胡敏酸碳、富里酸碳和颗粒有机碳含量最低;此外,岳桦林土壤的胡敏酸碳和富里酸碳含量显著高于其他林型土壤,岳桦-苔原土壤的水溶性有机碳含量显著高于其他林型土壤,而高山苔原土壤的有机碳和易氧化碳含量显著低于其他林型土壤。相关性分析表明,土壤有机碳含量与非晶质氧化铝含量呈显著的正相关关系(P0.05),富里酸碳含量与游离氧化铝含量呈显著的正相关关系(P0.05),而0.25~0.053 mm微团聚体有机碳含量与2种形态氧化铝含量都呈显著的正相关关系(P0.05)。上述结果指出,不同林型条件下各有机碳及其组分差异显著。  相似文献   

20.
开垦对黑土有机碳在有机无机复合体分配的影响   总被引:5,自引:0,他引:5  
本文研究了不同开垦年限黑土粘粒、粉砂和细砂级复合体中有机碳的分布特征及其变化规律,结果表明,黑土有机无机复合体组成以细砂级复合体为主,粘粒及粉砂级复合体次之。随着开垦年限的延长,黑土耕层和犁底层土壤粒粘级复合体的含量均有不同程度的增加,而粉粒及细砂级复合体的含量相应减少;黑土耕层各复合体中有机碳含量均明显减少,犁底层亦表现出降低的趋势。犁底层各复合体中有机碳含量占土壤有机碳含量的百分数表现各异,在粘粒级复合体中随着开垦年限延长趋于增加,而在粉粒和细砂级复合体中趋于减少。黑土耕层土壤粘粒级复合体中有机碳含量与粘粒级复合体含量呈明显的负相关,粉砂和细砂级复合体中有机碳含量与粉砂和细砂级复合体含量则呈明显的正相关。  相似文献   

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