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1.
杨木炭胶合成型速燃炭的制备与燃烧性能 总被引：1，自引：1，他引：0
为了研究了胶黏剂的类型、胶炭比、引燃剂的种类和添加量、成型压力、成型时间等因素对速燃炭燃烧性能的影响,该文利用杨木屑经炭化后得到杨木炭,以杨木炭为主要原料,添加适量不同种类的胶黏剂和引燃剂制备速燃炭。结果表明：将胶黏剂A和杨木炭以质量比为0.6︰1的胶炭比混合,并添加占杨木炭质量分数为5%的硝酸钾,在25 MPa的成型压力下保持2 min,制备出的速燃炭有较好的速燃效果。不仅具有一定强度,燃烧时无毒、无烟、无味,并能在 5 s内快速点燃速燃炭。速燃炭的抗压系数达8.60 N/mm2,燃烧剩余物的质量分数为6.33%,燃烧时间可持续11.20 min/g,热值达到35 762.76 J/g。该研究可为粉末燃料的成型胶黏剂研制提供依据。 相似文献
2.
黑碳添加对土壤有机碳矿化的影响 总被引：10，自引：0，他引：10
通过室内培养试验,向土壤中分别添加不同温度制备的黑碳,热解温度分别为350℃(T350)、600℃(T600)和850℃(T850),研究了黑碳添加对土壤有机碳矿化的影响。结果表明,不同温度条件制备的黑碳在15℃和25℃培养条件下,土壤CO2释放速率总的趋势是前期分解速率快,后期缓慢。在整个培养过程中(112天),随着培养时间的延长,土壤CO2释放速率下降趋势逐渐降低,CO2释放速率相对值的大小随着培养温度的的升高而增大。在不同温度培养条件下,添加黑碳后土壤CO2-C累计量均是T350>T600>T850,T350土壤CO2-C累计量最高分别为415.26 mg/kg和733.82 mg/kg。添加不同黑碳后,土壤有机碳矿化增加率存在极显著差异(p<0.01),表明不同温度制备的黑碳对土壤有机碳矿化的影响显著。 相似文献
3.
为探索不同碳源对土壤碳的提升作用,开展了不同碳源对烤烟生长季土壤碳平衡影响的研究,旨在为植烟土壤有机肥施用调控提供理论依据。试验设在四川省攀枝花市,以烤烟为供试作物进行田间小区试验。设对照(不施有机肥)、秸秆、农家肥、油枯、农家肥+油枯5个不同施肥处理,3次重复。采用VaisalaMI70土壤呼吸测量系统进行田间监测,并同时观测环境条件。对烤烟根系进行收集,测定土壤根系固碳量。研究结果显示,1)在烤烟生长季,植烟土壤呼吸动态呈倒"S"型的先下降后上升再下降的变化规律,施用有机肥增加了土壤呼吸强度,尤其是在有机肥施用初期。2)烤烟生长季碳排放量平均为385.84 kg·hm-2,不同处理碳排放量表现为对照293.11 kg·hm-2,秸秆396.9 kg·hm-2,农家肥363.36 kg·hm-2,油枯422.98 kg·hm-2,油枯+农家肥452.84kg·hm-2。3)不同碳源分解速率差异较大,生长季分解系数为0.22~0.42,秸秆和农家肥分解系数低于油枯。4)有机肥的施用对烤烟根系碳积累量的提升效果不明显,而各有机肥处理相比,农家肥以及农家肥与油枯混施相对于秸秆处理能够显著增加烤烟根系碳积累量。5)当地耕作模式下,整个生育期有56.42%的烤烟根系残留于土壤,可补偿土壤碳260.56 kg·hm-2,烤烟根系碳是常规施肥下土壤碳的主要来源。6)常规施肥下,单施化肥植烟土壤表现为碳源,有机无机配施下植烟土壤表现为碳汇。有机肥的施用能够提升土壤碳平衡,减少碳损失;采用农家肥与油枯混施也能够在一定程度上促进烤烟根系碳积累的提升。 相似文献
4.
不同地表覆盖栽培对旱地土壤有机碳、无机碳和轻质有机碳的影响 总被引：10，自引：1，他引：9
通过田间长期定位试验,分层采集冬小麦-休闲种植体系0—40 cm土层的土样,研究了常规、地表覆膜和覆草栽培对土壤有机碳、无机碳和轻质有机碳的影响。结果表明,覆膜或覆草可以显著增加地上部小麦生物量和子粒产量。不同地表覆盖对0—40 cm土层的无机碳含量和分布无显著影响,但与常规栽培相比,地表覆膜使0—5 cm土层的有机碳含量显著降低,0—40 cm各土层轻质有机碳表现出明显降低趋势,平均降低 C 6.1~74.5 mg/kg;地表覆草却表现出明显增加土壤轻质有机碳的趋势,0—5,5—10,10—20 cm土层的轻质有机碳含量分别增加C 235.2、190.0和144.9 mg/kg,相当于常规的38.7%,32.9%和34.5%。同时,覆草栽培还表现出降低0—10 cm土层轻质有机质含碳量的趋势,并使0—20 cm土层轻质有机碳占有机碳的比例显著高于常规栽培和地表覆膜处理。可见,地表长期覆膜不利于旱地土壤有机碳累积,覆草不仅可以增加表层土壤的轻质有机碳累积,还可改善土壤碳氮组成。 相似文献
5.
6.
施肥对土壤有机碳含量及碳库管理指数的影响 总被引：16，自引：0，他引：16
在华北夏玉米生产体系中,采用田间试验,研究了不同施肥措施下（不施肥、单施有机肥、推荐施肥、习惯施肥和单施化肥）,土壤有机碳含量、活性有机碳含量和碳库管理指数的变化。结果表明:与不施肥相比,单施有机肥土壤有机碳和活性有机碳含量分别增加 11.68%,21.71%。推荐施肥和习惯施肥土壤有机碳含量分别增加 6.57%,7.58%,活性有机碳含量分别增加 8.53%,4.26%。单施化肥土壤有机碳与活性有机碳含量均没有显著增加;施有机肥和推荐施肥土壤碳库管理指数比不施肥分别高 31.79,13.01。单施化肥土壤碳库管理指数没有显著变化;土壤活性有机碳与总有机碳、碳库管理指数、玉米子粒产量均存在极显著相关关系。碳库管理指数与玉米子粒产量极显著相关,能够指示土壤生产力的变化。可见在当地土壤肥力条件下,施有机肥或有机无机适当配施能提高土壤有机碳含量和土壤碳库管理指数,有利于改善土壤质量,提高土壤肥力。 相似文献
7.
不同农业废弃物还田对土壤碳排放及碳固定的影响 总被引：3，自引：1，他引：2
在玉米生长季,采用静态箱法,在氮磷钾等养分量(N 240kg/hm~2,P2O5100kg/hm~2,K2O 120kg/hm~2)的条件下,研究秸秆、牛粪、鸡粪与化肥配施还田,对土壤CO_2排放及碳固定的影响。研究结果表明:施肥促进土壤CO_2排放,其中100%秸秆粉碎还田配施化肥(S1)对土壤CO_2排放的促进作用最为明显,平均排放通量达389.0mg/(m~2·h);其次为单施化肥(S4)。S1、S2、S3和S4处理在6,7,8三个月份CO_2平均排放通量表现为S4S1S3S2,分别占整个生长季排放总量的80.1%,78.9%,78.8%和83.7%,表明单施化肥处理(S4)在玉米生长旺季CO_2排放通量最高达624.9mg/(m~2·h)。各施肥处理在玉米生长季出现2个CO_2排放高峰阶段,与2次氮肥(尿素)追施密切相关,2次追施氮肥后CO_2排放通量平均值均表现为S4S1S3S2,表明用农业废弃物中的氮部分代替化肥氮,可减少CO_2排放量。50%牛粪有机氮还田配施50%化肥氮(S2),能明显提高土壤有机碳含量。50%鸡粪有机氮还田配施50%化肥氮(S3)可明显提高玉米各器官及植株含碳量,其中S3处理植株含碳量最高为9.59t/hm~2,促进玉米碳固定;而100%秸秆粉碎还田配施化肥氮(S1),并不能提高玉米各器官及植株含碳量,甚至低于单施化肥(S4)。 相似文献
8.
We investigated the role of water-extractable carbon (C-extr) as potential substrate for forest soil microorganisms by comparing
belowground C fluxes at a plot with the forest floor removed (no-litter) and at a control plot. One-third lower soil respiration
rates at the no-litter plot gave evidence that the forest floor was the source of considerable amounts of microbially degradable
C. Laboratory incubation of C-extr, fractionated into neutral and acid moieties, showed that part of the C-extr was degraded
rapidly, and that the high-molecular-weight acid fraction was much less degradable than the neutral C. To the extent that
the degradable portion of the water-extractable C can be regenerated quickly, it may supply much of the substrate for heterotrophic
soil respiration.
Received: 11 December 1995 相似文献
9.
10.
长期施肥对土壤有机碳和无机碳的影响 总被引：16，自引：2，他引：14
利用18年长期定位试验,研究了在不同施肥条件下,土壤有机碳和无机碳在0~50 cm土层分布特征。结果表明,施肥对土壤有机碳的影响随着土层深度的增加而下降,0~7.5 cm土层的土壤有机碳比7.5~15 cm、15~30 cm、30~50 cm分别增加了4.6%、22.0%、63.1%,而无机碳含量随着土层深度的增加而增加,与有机碳的变化规律正好相反。不同种类的肥料对土壤有机碳的影响也不相同,化肥、有机肥长期配合施用和长期施用有机肥可以在0~30 cm土层增加土壤有机碳含量,降低土壤中的无机碳含量,而长期单施化肥对土壤的有机碳和无机碳含量无明显差异。 相似文献
11.
蔬菜连作对铜尾矿土壤中有机碳、腐殖质碳以及可溶性有机碳的影响 总被引：2，自引：0，他引：2
Carbon of humus acids （HSAC） and dissolved organic carbon （DOC） are the most active forms of soil organic carbon （SOC） and play an important role in global carbon recycling. We investigated the concentrations of HSAC, water-soluble organic carbon （WSOC）, hot water-extractable organic carbon （HWOC） and SOC in soils under different vegetation types of four copper mine tailings sites with differing vegetation succession time periods in Tongling, China. The concentrations of HSAC, WSOC, HWOC and SOC increased with vegetation succession. WSOC concentration increased with the accumulation of SOC in the tailings, and a linearly positive correlation existed between the concentrations of HSAC and SOC in the tailings. However, the percentages of HSAC and DOC in the SOC decreased during vegetation succession. The rate of SOC accumulation was higher when the succession time was longer than 20 years, whereas the speeds of soil organic matter （SOM） decomposition and humification were slow, and the concentrations of HSAC and DOC increased slowly in the tailings. The percentage of carbon of humic acid （HAC） in HSAC increased with vegetation succession, and the values of humification index （HI）, HAC/carbon of fulvic acid, also increased with the accumulation of HSAC and SOC in soils of the tailings sites. However, the HI value in the each of the tailings was less than 0.50. The humification rate of SOM was lower than the accumulation rate of SOM, and the level of soil fertility was still very low in the tailings even after 40 years of natural restoration. 相似文献
12.
C. Poeplau A. Don M. Dondini J. Leifeld R. Nemo J. Schumacher N. Senapati M. Wiesmeier 《European Journal of Soil Science》2013,64(6):735-746
Fractionation of soil is undertaken to isolate organic carbon with distinct functional properties, such as stability and turnover times. Soil organic carbon (SOC) fractionation helps us to understand better the response of SOC to changes in land use, management or climate. However, fractionation procedures are often poorly defined and there is little information available on their reproducibility in different laboratories. In a ring trial, we assessed the reproducibility of a SOC fractionation method introduced by Zimmermann et al. (2007). The isolated fractions were linked to the model pool sizes of the Rothamsted carbon model (RothC). We found significant differences between six laboratories for all five defined fractions in three different soils with coefficients of variation ranging from 14 to 138%. During ultrasonic dispersion, the output power (energy per unit time) was identified as an important factor controlling the distribution of SOC within these five fractions, while commonly only the output energy is standardized. The amount of water used to wet‐sieve dispersed soil slurry significantly influenced the amount of extracted dissolved organic carbon (DOC). We therefore suggest using a fixed amount of power for ultrasonic dispersion (20 W) and a minimum amount of water for wet sieving (2000 ml). RothC pool sizes were predicted from the measured fractions and compared with RothC equilibrium pool size distributions. This model initialization using measured SOC fractions, however, led to an over‐estimation of stable RothC SOC pools when compared with pool size distributions derived from RothC equilibrium runs under a bare fallow soil model simulation. To improve the isolation of particulate organic matter from stable mineral‐bound organic matter, we suggest that the density should be increased from 1.8 to 2.0 g cm?3 in the density fractionation step. We formulated a modified fractionation procedure, which aims specifically to enhance reproducibility across laboratories and to improve the match of the isolated SOC fractions with RothC's SOC pools. 相似文献
13.
J. Jin G. H. Wang J. D. Liu Z. H. Yu X. B. Liu S. J. Herbert 《European Journal of Soil Science》2013,64(4):500-507
The fate of photosynthetically‐fixed carbon (C) in the plant–soil–microbe continuum has received much interest because of its relevance to soil C and the global C cycle. However, information on the flow of this plant C below ground and its contribution to soil C sequestration in soils with contrasting organic C (Corg) is limited. In this study, soyabean (Glycine max L. Merr.) was grown in three Mollisols with low (1.04%), medium (2.90%) and high (5.05%) Corg, respectively. Plants were labelled with 13CO2 to trace the photosynthetic C dynamics in the plant–soil system for up to 288 hours. The total amount of net fixed 13C by plants ranged from 66 to 78 mg pot?1, and there was no difference between soils. The amount of 13C in soil organic matter (SOM) increased from 1.9 to 6.1 mg pot?1 over time in the high‐Corg soil, while it showed a non‐significant change with 2.2 mg pot?1 (on average) in the medium‐Corg soil, and decreased from 2.9 to 0.1 mg pot?1 in the low‐Corg soil. In the low‐Corg soil, the amount of 13C in soil microbes decreased markedly over time, showing a fast turnover, and had a significant correlation (P ≤ 0.01) with 13C in the SOM pool. However, such a relationship was not significant in the soil with high or medium Corg. These results indicate that most of the root‐derived C in the low‐Corg soil is degraded quickly by microbial activity, while the greater input of the photosynthetic C to SOM in the high‐ and/or medium‐Corg soil can probably be attributed to physical sorption of root‐derived C by SOM and minerals, thus protecting it against microbial decomposition. 相似文献
14.
干湿交替对土壤碳库和有机碳矿化的影响 总被引：15，自引：0，他引：15
水分是影响土壤活性碳库和惰性碳库周转过程的主导因子,而土壤有机碳的周转速率会对气候变化造成潜在的重要影响。以农田水稻土为供试土壤,通过培育试验研究了干湿交替过程对土壤有机碳矿化的影响,并利用两库叠加模型对土壤不同碳库及其降解动力学进行初步评估。结果表明:干湿交替激发了土壤呼吸,增加了土壤微生物代谢活性。三次湿润过程对土壤呼吸的激发量分别为119.3%、159.5%和87.3%,激发效应随干湿交替频率的增加先升高后降低。多次干湿交替后,土壤累积CO2释放量低于恒湿土壤,湿润所引起的激发的矿化量不足以弥补干旱期降低的矿化量。在湿润的数小时内,土壤溶解性有机碳含量先升高后降低。干湿交替提升了土壤活性碳库的降解速率,降低了惰性碳库的降解速率,湿润后土壤活性碳库显著增加。多次干湿交替降低了土壤真菌/细菌比,使土壤微生物群落结构发生变化,细菌成为优势种群。 相似文献
15.
C. Vernon Cole Keith Paustian Edward T. Elliott Alister K. Metherell Dennis S. Ojima William J. Parton 《Water, air, and soil pollution》1993,70(1-4):357-371
We present analyses of major driving variable controls on soil C in agroecosystems. Historical changes in soil C storage in agricultural soils are characterized by large losses during transition from natural grasslands and forests. A major driver in more recent times is the steadily increasing rate of net primary production of major land areas in agriculture. Simulation and analytical models are used to predict trajectories and potential soil C storage under possible scenarios of changed management and climate. Database and analytical requirements for extrapolation from regional to global scales are outlined. 相似文献
16.
《Communications in Soil Science and Plant Analysis》2012,43(17-18):2203-2212
Abstract The oxidable carbon content of 46 calcareous soils from the South‐East of Spain was determined by the Walkley and Black method and compared with the total organic carbon (C) content obtained by an automatic microanalysis method. The results were fitted to linear, curvilinear, and exponential equations which permit the conversion of the oxidable C values into those of total organic C when no direct means of analysis of the latter is available. A conversion factor of 1.26 is recommended. 相似文献
17.
河北省北部森林植被碳储量和固碳速率研究 总被引：2，自引：1，他引：1
为了了解河北省北部森林植被固碳能力,本文以该区域阔叶林、针叶林、混交林、经济林和灌丛为研究对象,基于政府间气候变化专门委员会(IPCC)推荐采用的加拿大林业碳收支模型(CBM-CFS3),利用第7次全国森林资源连续清查数据和野外森林植被调查样地数据,拟合出研究区的蓄积-生物量转换参数和林木器官生物量比例参数,建立研究区内不同森林植被类型的蓄积生长方程、蓄积-干材生物量转换方程、生物量组分比例方程,采用这些方程评估了2010年河北省北部森林生态系统植被碳储量、碳密度和固碳速率。结果表明:拟合的不同森林植被蓄积生长方程的决定系数均大于0.7,蓄积-干材生物量转换方程的决定系数均大于0.8,生物量组分比例方程拟合效果较好,可用于评估该区域森林植被碳汇功能和潜力。2010年河北省北部森林植被碳储量为59.66 Tg(C),平均森林植被碳密度为25.05 Mg(C)×hm~(-2),森林植被固碳速率为0.07~1.87Mg(C)×hm~(-2)×a~(-1);其中阔叶林、针叶林、混交林、经济林碳储量和碳密度分别为30.97 Tg(C)、12.36 Tg(C)、15.73Tg(C)、0.60 Tg(C)和26.09 Mg(C)×hm~(-2)、26.14 Mg(C)×hm~(-2)、24.50 Mg(C)×hm~(-2)、7.53 Mg(C)×hm~(-2)。河北省北部森林植被碳密度与固碳速率均从西北到东南呈升高趋势。造林后森林面积增加6 400 km2,森林植被碳储量增加19.54 Tg(C)(不包括灌丛);林龄结构以中幼龄林为主,未来森林固碳潜力巨大。说明造林在增加森林植被碳储量和提高森林的固碳速率中起到了重要作用。 相似文献
18.
矿区复垦土壤碳组分对外源碳输入的响应特征 总被引：1，自引：0，他引：1
研究外源碳输入对复垦土壤有机碳及组分的影响,对于深入探究矿区复垦土壤有机碳提升及培肥管理具有重要意义。本文依托山西省襄垣县采煤沉陷复垦区的长期定位试验,研究了矿区复垦土壤碳组分对不同外源碳(生物炭、堆肥、沼渣、牛粪与秸秆)输入的响应特征。分别在2011年与2016年对矿区复垦土壤样品进行采集,测定0～20 cm土层土壤有机碳、易氧化有机碳、活性碳库Ⅰ、Ⅱ的含量。结果表明,生物炭处理的土壤有机碳增长率和年变化量较对照(CK,无外源碳添加)分别增加101.80%和0.56g·kg–1·a–1,且均显著高于其他有机物料处理;生物炭、牛粪处理土壤0～20 cm土层固碳量较CK分别提高100.52%和91.52%,二者间差异不显著,均显著高于其他有机物料处理,堆肥、沼渣和秸秆处理间对土壤固碳量的提升作用不显著。添加有机物料均能显著增加复垦土壤易氧化有机碳的增长率和年变化量,均表现为堆肥处理最高,较CK分别增加12.37%和0.16 g·kg–1·a–1。复垦土壤活性碳库Ⅰ、Ⅱ的增长率和年变化量均为牛粪处理显著高于其他有机物料处理。有机物料添加均能提高土壤稳定性有机碳含量,与CK相比,生物炭和牛粪处理的提高幅度最大,显著高于其他有机物料,而牛粪与生物碳之间差异不显著。生物炭处理碳库管理指数最高,分别较堆肥、沼渣、牛粪、秸秆处理提高36.30%、52.23%、41.50%、52.02%。施用生物炭、堆肥、沼渣、牛粪与秸秆都能显著提升复垦土壤各碳组分含量和碳库管理指数,施用生物炭的效果最优,因此施用生物炭可作为矿区复垦土壤有机碳提升的有效管理措施。 相似文献
19.
The chemical composition and quantity of plant inputs to soil are primary factors controlling the size and structure of the soil microbial community. Little is known about how changes in the composition of the soil microbial community affect decomposition rates and other ecosystem functions. This study examined the degradation of universally 13C-labeled glucose, glutamate, oxalate, and phenol in soil from an old-growth Douglas-fir (Pseudotsuga menziesii)—western hemlock (Tsuga heterophylla) forest in the Oregon Cascades that has experienced 7 y of chronic C input manipulation. The soils used in this experiment were part of a larger Detritus Input and Removal Treatment experiment and have received normal C inputs (control), doubled wood inputs, or root and litter input exclusion (no inputs). Soil from the doubled wood treatment had a higher fungal:bacterial ratio, and soil from the no inputs treatment had a lower fungal:bacterial ratio, than the control soil. Differences in the utilization of the compounds added to the field-manipulated soils were assessed by following the 13C tracer into microbial biomass and respiration. In addition, 13C-phospholipid fatty acids (PLFA) analysis was used to examine differential microbial utilization of the added substrates. Glucose and glutamate were metabolized similarly in soils of all three litter treatments. In contrast, the microbial community in the double wood soil respired more added phenol and oxalate, whereas microbes in the no inputs soil respired less added phenol and oxalate, than the control soil. Phenol was incorporated primarily into fungal PLFA, especially in soil of the double wood treatment. The addition of all four substrates led to enhanced degradation of soil organic matter (priming) in soils of all three litter treatments, and was greater following the addition of phenol and oxalate as compared to glucose and glutamate. Priming was greater in the no inputs soil as compared to the control or doubled wood soils. These results demonstrate that altering plant inputs to soil can lead to changes in microbial utilization of C compounds. It appears that many of these changes are the result of alteration in the size and composition of the microbial community. 相似文献
20.
农地集约利用的碳排放效率分析与低碳优化 总被引：6，自引：1，他引：5
提高农地利用集约水平与控制农地利用碳排放量容易陷入两难选择的困境,理想的碳排放效率可以寻找到以碳排放作为成本,适度的农地利用集约水平。该文构建农地集约利用度计算模型与农地集约利用投入产出指标,计算中国31个省份的农地集约利用度;基于松弛测度(slacks-based measure,SBM)模型,构建SBM模型投入产出指标,计算各省份的农地集约利用碳排放总效率、技术效率与规模效率。研究结果表明:农地集约利用程度高低与农地集约利用碳排放总效率高低并不保持普遍一致;农地集约利用碳排放总效率有效省份集中分布在西部地区,农地集约利用度较高的长三角、珠三角、京津冀地区主要省份的农地集约利用碳排放总效率普遍较低;区域农地集约利用碳排放技术效率不足是导致总效率偏低的主要原因,而规模效率不足对总效率影响较小。因此针对总效率无效省份,给出调整投入冗余量、期望产出不足量与非期望产出冗余量的低碳优化方案,并构建结合了东、中、西部地区区域农地利用与经济发展特点的低碳优化策略,以期最终可以改善农地集约利用碳排放效率。 相似文献