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1.
Impacts of land management on fluxes of trace greenhouse gases 总被引:8,自引:0,他引:8
Abstract. Land use change and land management practices affect the net emissions of the trace gases methane (CH4 ) and nitrous oxide (N2 O), as well as carbon sources and sinks. Changes in CH4 and N2 O emissions can substantially alter the overall greenhouse gas balance of a system. Drainage of peatlands for agriculture or forestry generally increases N2 O emission as well as that of CO2 , but also decreases CH4 emission. Intermittent drainage or late flooding of rice paddies can greatly diminish the seasonal emission of CH4 compared with continuous flooding. Changes in N2 O emissions following land use change from forest or grassland to agriculture vary between climatic zones, and the net impact varies with time. In many soils, the increase in carbon sequestration by adopting no-till systems may be largely negated by associated increases in N2 O emission. The promotion of carbon credits for the no-till system before we have better quantification of its net greenhouse gas balance is naïve. Applying nitrogen fertilizers to forests could increase the forest carbon sink, but may be accompanied by a net increase in N2 O; conversely, adding lime to acid forest soils can decrease the N2 O emission. 相似文献
2.
Jing MA Kazuyuki YAGI Hua XU Yong HAN Zucong CAI 《Soil Science and Plant Nutrition》2008,54(4):638-643
Burial of wheat straw in ditches and incorporation of wheat straw are the two main ways of returning wheat straw prior to rice cultivation in China. To examine the effect of burying wheat straw in ditches on CH4 emissions from rice cultivation, a field experiment was conducted at Yixing, Jiangsu, China in 2004. CH4 flux was measured using a closed-chamber technique in three treatments (CK, no wheat straw application; WI, evenly incorporating 3.75 t ha−1 wheat straw into the 0.1 m topsoil; WD, burying 3.75 t ha−1 wheat straw in 0.14-m deep by 0.25-m wide ditches). Seasonal CH4 emissions ranged from 49.7 to 218.4 kg CH4 ha−1 . The application of wheat straw in these two ways significantly increased CH4 emissions by 4.0-fold and 4.4-fold, respectively ( P < 0.05). Although CH4 flux from the non-ditch area in the WD treatment was as low as that in the CK treatment, it was counter-balanced by extremely high CH4 flux from the ditch, which was approximately 6.0-fold as much as that from WI, leading to comparability between treatments WI and WD in total CH4 emissions ( P > 0.05). No significant difference was observed between the three treatments in grain yield ( P > 0.05). The results indicated that burial of wheat straw in ditches is not a way to reduce CH4 emission from rice cultivation. 相似文献
3.
Methane fluxes on agricultural and forested boreal organic soils 总被引:2,自引:0,他引:2
Abstract. Annual methane fluxes from an organic soil in eastern Finland, originally drained and planted with birch ( Betula pendula ) and then later cultivated, were studied for two years using a chamber technique. The agricultural soils growing grass or barley or without vegetation, generally acted as sinks for CH4 . Surprisingly, the agricultural soils emitted CH4 during a warm dry summer. The CH4 oxidation capacity and CH4 uptake rate of the forested site was three times that of agricultural soils. Also, the forest soil better retained its capacity to take up CH4 during a dry summer. Despite periods of CH4 emission, the agricultural soils were annual sinks for CH4 , with uptake rate of CH4 -C varying from 0.1 to 3.7 kg ha−1 yr−1 . The forested soil had a methane uptake rate of 3.9 kg CH4 -C ha−1 yr−1 . All the soils acted as sinks for CH4 during winter, which contributed up to half of the annual CH4 uptake. The capacity of soils to transport gases did not explain the larger CH4 uptake rate in the forest soil. At the same gas filled porosity, the forest soil had a much larger CH4 uptake rate than the agricultural soil. Neither the soil acidity (pH 4.5 and 6.0) nor high ammonium content appeared to limit CH4 uptake. The results suggest that CH4 oxidation in agricultural organic soil is more sensitive to soil drying than CH4 oxidation in forested organic soil. 相似文献
4.
Å. Kasimir Klemedtsson P. Weslien & L. Klemedtsson 《European Journal of Soil Science》2009,60(3):321-331
Fluxes of the greenhouse gases methane (CH4 ) and nitrous oxide (N2 O) from histosolic soils (which account for approximately 10% of Swedish agricultural soils) supporting grassley and barley production in Sweden were measured over 3 years using static chambers. Emissions varied both over area and time. Methane was both produced and oxidized in the soil: fluxes were small, with an average emission of 0.12 g CH4 m−2 year−1 at the grassley site and net uptake of −0.01 g CH4 m−2 year−1 at the barley field. Methane emission was related to soil water, with more emission when wet. Nitrous oxide emissions varied, with peaks of emission after soil cultivation, ploughing and harrowing. On average, the grassley and barley field had emissions of 0.20 and 1.51 g N2 O m−2 year−1 , respectively. We found no correlation between N2 O and soil factors, but the greatest N2 O emission was associated with the driest areas, with < 60% average water-filled pore space. We suggest that the best management option to mitigate emissions is to keep the soil moderately wet with permanent grass production, which restricts N2 O emissions whilst minimizing those of CH4 . 相似文献
5.
The formation of CH3 ONO in 11 soils treated with HNO2 or NaNO2 in a closed system, was studied by measuring the concentration in the gas space above the soil and by absorbing CH3 ONO in HI. The gaseous concentration of CH3 ONO increased and then decreased following additions of HNO2 or NaNO2 , and the production of CH3 ONO increased with increasing concentrations of HNO2 or NaNO2 added to soils.
The amounts of CH3 ONO trapped in HI were 13.5 to 20.4 times higher than those determined by integrating under the net production curves. The evolved CH3 ONO amounted to 0.4 to 3.5% of added NO2 − , and 4.2 to 50% of the gaseous forms of N absorbed by acidic KMnO4 solution. The CH3 ONO evolved from soils was positively correlated with the methoxy content of the soils, and inversely related to soil pH, with negligible amounts being evolved from alkaline soils. The results show that CH3 ONO is a product of NO2 − decomposition in soils, and indicate that small concentrations of the gas may be produced in N–fertilized soils in which NO2 − accumulates. 相似文献
The amounts of CH
6.
Coniferous forest soils often consume less of the greenhouse gas methane (CH4 ) than deciduous forest soils. The reasons for this phenomenon have not been resolved. It might be caused by differences in the diffusive flux of CH4 through the organic layer, pH or different concentrations of potentially inhibitory compounds. Soil samples were investigated from three adjacent European beech ( Fagus sylvatica ) and Norway spruce ( Picea abies ) stands in Germany. Maximal CH4 oxidation velocities (Vmax(app) ) and Michaelis Menten constants (KM(app) ), retrieved from intact soil cores at constant CH4 concentrations, temperature and matric potential, were twice as great in beech as in spruce soils. Also atmospheric CH4 oxidation rates measured in homogenized soil samples displayed the same trend. Greatest atmospheric CH4 oxidation rates were detected in the Oa horizon or in the upper 5 cm of the mineral soil. In contrast to the beech soils, the Oa horizon of the spruce soils consumed no CH4 . A differential effect due to divergent diffusive flux through the litter layer was not found. pH and ammonium concentration were similar in samples from both forest soil types. Ethylene accumulation in all soils was negligible under oxic conditions. These collective results suggest that the different atmospheric CH4 uptake by beech and spruce soils is caused by different CH4 oxidizing capacities of methanotrophic communities in the Oa horizon and top mineral soil. 相似文献
7.
Abstract. The effects of especially frequent nitrogen (N) additions (from 1959 to 1986, totalling 860 kg N ha−1 ) and liming (in 1958 and 1980, totalling 6000 kg CaCO3 ha−1 ) on CH4 uptake by a boreal forest soil were studied in a stand of Norway spruce. Except for a forested reference plot, the stand was clear-cut in January 1993 and the following year one-half of each clear-cut plot was prepared by mounding. Fluxes of CH4 were measured with static chambers in the autumn before clear-cutting and during the following four summers. The average CH4 uptake during 1993–96 in the forested reference plot was 82 μg CH4 m−2 h−1 (ranging from 10 to 147 units). In the first summer after clear-cutting, the cleared plot showed 42% lower CH4 uptake rate than the forested reference plot, but thereafter the difference became less pronounced. The short-term decrease in CH4 consumption after clear-cutting was associated with increases in soil NH4 + and NO3 − concentrations. Mounding tended at first to stimulate CH4 uptake but later to inhibit it. Neither liming nor N-fertilization had significant effects on CH4 consumption. Our results suggest that over the long term, in N-limited upland boreal forest soils, N addition does not decrease CH4 uptake by the soil. 相似文献
8.
Mitigation of greenhouse gas emissions from soil under silage production by use of organic manures or slow-release fertilizer 总被引:4,自引:0,他引:4
Abstract. Grassland is a major source of nitrous oxide (N2 O) and methane (CH4 ) emissions in the UK, resulting from high rates of fertilizer application. We studied the effects of substituting mineral fertilizer by organic manures and a slow-release fertilizer in silage grass production on greenhouse gas emissions and soil mineral N content in a three-year field experiment. The organic manures investigated were sewage sludge pellets and composted sewage sludge (dry materials), and digested sewage sludge and cattle slurry (liquid materials). The organic manures produced N2 O and carbon dioxide (CO2 ) consistently from time of application up to harvest. However, they mitigated N2 O emissions by around 90% when aggregate emissions of 15.7 kg N ha−1 from NPK fertilizer were caused by a flux of up to 4.9 kg N ha−1 d−1 during the first 4 days after heavy rainfall subsequent to the NPK fertilizer application. CH4 was emitted only for 2 or 3 days after application of the liquid manures. CH4 and CO2 fluxes were not significantly mitigated. Composting and dried pellets were useful methods of conserving nutrients in organic wastes, enabling slow and sustained release of nitrogen. NPK slow-release fertilizer also maintained grass yields and was the most effective substitute for the conventional NPK fertilizer for mitigation of N2 O fluxes. 相似文献
9.
Greenhouse gas emissions from farmed organic soils: a review 总被引:14,自引:0,他引:14
Å. Kasimir-Klemedtsson L. Klemedtsson K. Berglund P. Martikainen J. Silvola O. Oenema 《Soil Use and Management》1997,13(S4):245-250
Abstract. The large boreal peatland ecosystems sequester carbon and nitrogen from the atmosphere due to a low oxygen pressure in waterlogged peat. Consequently they are sinks for CO2 and strong emitters of CH4 . Drainage and cultivation of peatlands allows oxygen to enter the soil, which initiates decomposition of the stored organic material, and in turn CO2 and N2 O emissions increase while CH4 emissions decrease. Compared to undrained peat, draining of organic soils for agricultural purposes increases the emissions of greenhouse gases (CO2 , CH4 , and N2 O) by roughly 1t CO2 equivalents/ha per year. Although farmed organic soils in most European countries represent a minor part of the total agricultural area, these soils contribute significantly to national greenhouse gas budgets. Consequently, farmed organic soils are potential targets for policy makers in search of socially acceptable and economically cost-efficient measures to mitigate climate gas emissions from agriculture. Despite a scarcity of knowledge about greenhouse gas emissions from these soils, this paper addresses the emissions and possible control of the three greenhouse gases by different managements of organic soils. More precise information is needed regarding the present trace gas fluxes from these soils, as well as predictions of future emissions under alternative management regimes, before any definite policies can be devised. 相似文献
10.
Akinori Mori Masayuki Hojito Hiroshi Kondo Hisaya Matsunami David Scholefield 《Soil Science and Plant Nutrition》2005,51(1):19-27
To investigate the effects of plant species in grassland on methane (CH4 ) and nitrous oxide (N2 O) fluxes from soil, fluxes from an orchardgrass ( Dactylis glomerata L.) grassland, white clover ( Trifolium repens L.) grassland and orchardgrass/white clover mixed grassland were measured weekly from April 2001 to March 2002 using a vented closed chamber method. Related environmental parameters (soil inorganic N content, soil pH (H2 O) value, soil moisture content, soil temperature, grass yield, and the number of soil microorganisms) were also regularly monitored. On an annual basis, CH4 consumption in the soil of the orchardgrass grassland, white clover grassland and orchardgrass/white clover mixed grassland was 1.8, 2.4, and 1.8 kg C ha−1 year−1 , respectively. The soil bulk density of the white clover grassland was lower than that of the other grasslands. Fluxes of CH4 were positively correlated with the soil moisture content. White clover increased the CH4 consumption by improving soil aeration. Nitrogen supply to the soil by white clover did not decrease the CH4 consumption in the soil of our grasslands. On the other hand, annual N2 O emissions from the orchardgrass grassland, white clover grassland, and orchardgrass/white clover mixed grassland were 0.39, 1.59, and 0.67 kg N ha−1 year−1 , respectively. Fluxes of N2 O were correlated with the NO3 − content in soil and soil temperature. White clover increased the N2 O emissions by increasing the inorganic N content derived from degrading white clover in soil in summer. 相似文献
11.
J.-F. Soussana P. Loiseau N. Vuichard E. Ceschia J. Balesdent T. Chevallier D. Arrouays 《Soil Use and Management》2004,20(2):219-230
Abstract. Temperate grasslands account for c. 20% of the land area in Europe. Carbon accumulation in grassland ecosystems occurs mostly below ground and changes in soil organic carbon stocks may result from land use changes (e.g. conversion of arable land to grassland) and grassland management. Grasslands also contribute to the biosphere–atmosphere exchange of non-CO2 radiatively active trace gases, with fluxes intimately linked to management practices. In this article, we discuss the current knowledge on carbon cycling and carbon sequestration opportunities in temperate grasslands. First, from a simple two-parameter exponential model fitted to literature data, we assess soil organic carbon fluxes resulting from land use change (e.g. between arable and grassland) and from grassland management. Second, we discuss carbon fluxes within the context of farming systems, including crop–grass rotations and farm manure applications. Third, using a grassland ecosystem model (PaSim), we provide estimates of the greenhouse gas balance, in CO2 equivalents, of pastures for a range of stocking rates and of N fertilizer applications. Finally, we consider carbon sequestration opportunities for France resulting from the restoration of grasslands and from the de-intensification of intensive livestock breeding systems. We emphasize major uncertainties concerning the magnitude and non-linearity of soil carbon stock changes in agricultural grasslands as well as the emissions of N2 O from soil and of CH4 from grazing livestock. 相似文献
12.
Abstract. Many former estimates of regional scale C sequestration potential have made use of linear regressions based on long-term experimental data, whilst some have used dynamic soil organic matter (SOM) models linked to spatial databases. Few studies have compared the two methods. We present a case study in which the potential of different land management practices to sequester carbon in soil in arable land is estimated by different methods. Two dynamic SOM models were chosen for this study, RothC (a soil process model) and CENTURY (a whole ecosystem model with a SOM module). RothC and CENTURY are the two most widely used and validated SOM models worldwide. A Geographic Information System (GIS) containing soil, land use and climate layers, was assembled for a case study in central Hungary. GIS interfaces were developed for the RothC and CENTURY models, thus linking them to the spatial datasets at the regional level. This allowed a comparison of estimates of the C sequestration potential of different land management practices obtained using the two models and using regression based approaches. Although estimates obtained by the different approaches were of the same order of magnitude, differences were observed. Some of the land management scenarios studied here showed sufficient C mitigation potential to meet Hungarian CO2 reduction commitments. For example, afforestation of 12% current arable land could sequester 0.042–0.092 Tg yr–1 in the soil alone, or 0.285–0.588 Tg C yr–1 in both soil and biomass; 1990 level CO2 emissions for the study area were 4.7 Tg C with a corresponding reduction commitment of 0.282 Tg C. It is not, however, suggested that this is the only, or the most favourable way, in which to meet the commitments. 相似文献
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14.
Abstract. A carbon emission inventory of the Brazilian agricultural sector was used to compare greenhouse gas emissions with estimated carbon offsets promoted by two main changes in agricultural management: the replacement of conventional tillage by no-tillage and the cessation of annual burning in sugar cane production. Using the IPCC revised 1996 guidelines for national greenhouse gas inventories, we estimate that 12.65 Mt C are emitted annually from agricultural land in Brazil. Ongoing conversion of conventionally tilled land to no-tillage currently accumulates 9 Mt C yr−1 . Industrial by-products like alcohol and bagasse from sugar cane processing substitute fossil fuel for transportation and power generation offsetting 10 and 8 Mt C yr−1 , respectively. An additional opportunity for 0.53 Mt C yr−1 sequestration is presented by avoiding burning before harvesting of sugar cane. These data show that there could be almost full compensation between sources and sinks/offsets in the agricultural carbon cycle. There is a great opportunity to achieve this mitigation benefit because the adoption of new technologies is increasing rapidly. 相似文献
15.
Mizuhiko Nishida Mihoko Moriizumi Kazunari Tsuchiya 《Soil Science and Plant Nutrition》2005,51(4):577-581
The N recovery from 15 N-labeled swine manure compost and rice bran with or without simultaneous application of unlabeled cattle manure compost was examined in a paddy field with direct-seeded rice during a 1-year period (1 crop season). In all the 15 N-labeled materials including (15 NH4 )2 SO4 , the processes of N recovery from the 15 N materials by rice plants were different between the plots with and without application of cattle manure compost. At the tillering stage, the N recovery rates from the 15 N materials in the plots with application of cattle manure compost were significantly lower than those in the plots without application of cattle manure compost. These recovery rates, however, became close and no significant differences were observed at the maturity stage. Thus, simultaneous application of cattle manure compost could impede the N recovery from swine manure compost, rice bran as well as (NH4 )2 SO4 . 相似文献
16.
等养分投入下冬种紫云英比秸秆还田更有效抑制稻田CH4的产生和排放 总被引:1,自引:0,他引:1
【目的】比较冬种紫云英和水稻秸秆还田对稻田甲烷(CH4)产生、排放的影响,探究冬种紫云英的节肥效应和CH4减排机制。【方法】田间试验在湖南省农业科学院高桥试验基地进行,种植制度为单季超级稻‘晶两优华占’。田间试验设置1个不施肥对照(CK)和5个等氮磷钾养分施肥处理:单施化肥(CF)、化肥+水稻秸秆全量还田(S)、化肥+紫云英全量还田(M)、化肥+秸秆和紫云英全量还田(MS)、化肥+秸秆和紫云英全量还田+熟石灰(MSC)。在水稻分蘖初期(2021年6月21日),采用密闭式静态暗箱监测稻田CH4排放通量,通过底座侧面的接口采集田面水溶存CH4,同时每个小区按“S”形随机取0—20 cm土层土壤样品,一份用于测定理化性质,一份用于室内甲烷产生潜力和甲烷氧化潜力培养试验。【结果】1)田间试验中,供试稻田CH4排放通量范围为5.70~26.65 mg/(m2·h),虽然处理间差异未达显著水平,施肥处理的CH4排放通量均高于CK,S、MS、MSC... 相似文献
17.
A simple process-based model for estimating ammonia emissions from agricultural land after fertilizer applications 总被引:1,自引:0,他引:1
Abstract. Fertilizer applications to agricultural land are a significant source of ammonia (NH3 ) emission to the atmosphere, accounting for approximately 10% of the total emissions from agriculture. Current estimates of emissions from fertilizer applications use 'fixed' emission factors. This paper describes a model in which the emission factors are expressed as a function of the important influencing variables: fertilizer type, soil pH, land use, application rate, rainfall and temperature. Total emission in 2002 for the UK were estimated by running the model for a 'standard UK' scenario, viz. 28.7 kt NH3 -N, which compares well with the UK inventory estimate of 30.4 kt NH3 -N. Differences exist in the estimates for specific fertilizer types, with the mean emission factor for urea applications to grassland, in particular, being lower by use of this model (13% compared with 23% of applied N for the UK inventory). Emission estimates were most sensitive to temperature and fertilizer type. Scenario testing showed that significant reductions in emission could be achieved by replacing urea with other forms of N fertilizer, by combining urea use with a urease inhibitor, or by modifying some management practices. 相似文献
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晚稻期间秸秆还田对早稻田CH_4和N_2O排放以及产量的影响 总被引:2,自引:0,他引:2
选取湖南双季稻田为研究对象,采用静态箱-气相色谱法对晚稻期间秸秆还田配施减量化肥(DNPK+RS)和施化肥(NPK)处理下后季早稻田(2009年)的CH4和N2O排放通量进行观测。结果表明,在早稻田等量化肥条件下,DNPK+RS比NPK增加早稻田CH4排放的81%,减少N2O排放的53%。早稻产量表明,DNPK+RS显著低于NPK(P<0.05)。晚稻期间以秸秆还田来代替部分化肥,会降低次年早稻的有效穗数和肥料增产效应。DNPK+RS处理的单位产量的全球增温潜势为NPK的2倍。秸秆还田应该重视与化肥的搭配比例,否则会降低水稻产量,同时增加下季早稻的温室效应。 相似文献
20.
Carbon sequestration and saving potential associated with changes to the management of agricultural soils in England 总被引:3,自引:0,他引:3
Abstract. The potential for soil organic carbon sequestration, energy savings and the reduction of the emission of greenhouse gases were investigated for a range of changes in the management of tilled land and managed grassland. These parameters were modelled on a regional basis, according to local soils and crop rotations in England, and avoided the use of soil related indices. The largest carbon sequestration and saving contribution possible comes from an increase in the proportion of permanent woodland, such that a 10% change in land use could amount to 9 Mt C yr−1 in the initial years (arable and grassland). Changes in arable management could make a significant contribution to an abatement strategy if carried out in concert with greater use of permanent conservation field margins, increased returns of crop residues and reduced tillage systems, contributing 1.3 Mt C yr−1 in the initial years. It should be noted, however, that true soil carbon sequestration would be only a minor component of this (125 kt C yr−1 ), the main part being savings on CO2 emissions from reduced energy use, and lower N2 O emissions from reduced use of inorganic nitrogen fertilizer. 相似文献