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Economic Growth, CH<sub>4</sub>and n<sub>2</sub>o Emissions in Sudan: Where Should the Policy Focus Be?

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Journal of Geoscience and Environment Protection 2020年第10期8卷 202-229页

作者： Elwasila Saeed Elamin Mohamed Department of Economics University of Khartoum Khartoum Sudan

This study aimed to investigate the effect of economic growth, agricultural growth and energy use on methane (CH4) and nitrous oxide (n2o) emissions in Sudan. Within the context of the EKC, the study applies the oLS, ... 详细信息

This study aimed to investigate the effect of economic growth, agricultural growth and energy use on methane (CHsub>4sub>) and nitrous oxide (n2o) emissions in Sudan. Within the context of the EKC, the study applies the oLS, cointegration, vector error correction modelling (VECM) and Granger causality methods. The study has established a long run equilibrium relationship for both CHsub>4sub> and n2o in their relation to economic growth, agricultural growth and energy use in presence of trade openness (ToP) and inflows of foreign direct investments (FDI). The estimated VECM shows that emissions of CHsub>4sub> are significantly affected by economic growth, ToP, and FDI with no effect of agricultural growth in the short run while CHsub>4sub> is found to be significantly affected by economic growth, agricultural growth, ToP and FDI in the long run. The estimated VECM for n2o shows that n2o emissions are more significantly affected by energy use, agricultural growth and FDI with no effect of economic growth in the short run, while n2o is found to be significantly affected by economic growth, agricultural growth, ToP and FDI in the long run. Consistently, findings from the estimated oLS and VECMs show that the EKC does not hold for either CHsub>4sub>, or n2o emissions, and that n2o emissions are more significantly affected by economic growth, agricultural growth and energy use than emissions of CHsub>4sub>. Findings from impulse response and variance decomposition analysis confirm that emissions of n2o are more responsive to economic growth, agricultural growth and energy use than emissions of CHsub>4sub>. Granger causality analysis shows existence of bidirectional relationship between CHsub>4sub> and agricultural growth, but a unidirectional relationship from CHsub>4sub> to FDI. For n2o, the study finds a unidirectional relationship running from a

关键词： CH4 n2o GDP per Capita Agricultural Growth Energy Use Trade openness FDI Cointegration VECM Sudan

Measurements of atmospheric n_2o concentration and its emission fluxes from soil in China

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Science China Chemistry 1995年第9期38卷 1101-1107页

作者：王少彬宋文质苏维瀚曾江海王智平张玉铭 Research Centre for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Institute of Agricultural Modernization Chinese Academy of SciencesShijiazhuang 050021China

Air samples in China were collected and determined for the concentration of n2*** production rates of n2o from agricultural soils were measured with the chamber *** results in-dicate that the background concentration ... 详细信息

Air samples in China were collected and determined for the concentration of nsub>2sub>*** production rates of n2o from agricultural soils were measured with the chamber *** results in-dicate that the background concentration of n2o averages（308±5）×10-9in 1989,which is close to that ob-tained at the other background stations ***,at both urban and rural areas,atmospheric n2oconcentrations are higher.n2o emission fluxes from several farmlands are different and dependent on the fac-tors of agricultural practice and *** their magnitudes are at the same *** calculationshows that the released n2o-n from agricultural sources（cultivated soil and n-fertilizers）amounts to 122Gg/a in China in 1990.

关键词： n2o atmospheric concentration soft n-fertilizer flux.

n_2o emissions from regional agricultural lands——A case study of Guizhou Province, southwestern China

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Science China Earth Sciences 2000年第1期43卷 103-112页

作者：徐文彬洪业汤陈旭晖 C.S.Li State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Institute of Environment and Resources Chemistry Zhejiang University Hangzhou 310027 China Soil and Fertilizer Institute Guizhou Academy of Agricultural Sciences Guiyang 550013 China Institute for the Study of Earth Oceans and Space University of New Hampshire Durham USA.

To preliminarily study n2o emissions and the importance of environmental parameters on n2o flux from subtropical agroecosystem in China, n2o flux measurements were made at three cultivated agricultural lands in Guizhou Province, southwestern China. Based on the test and validation of daily n2o flux and its several associated variables between DnDC model and field measurements, DnDC model has been employed to estimate total n2o emissions from entire agricultural lands and its spatial distribution at county scale in Guizhou in 1995, and to assess the contributions of cropping practices on n2o emissions.

关键词： n2o emission agricultural lands DnDC model

Preliminary study of greenhouse gases in loess in Weinan, Shaanxi Province

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Chinese Science Bulletin 1997年第11期42卷 921-924页

作者： Liu, JQ Zhong, H Liu, DS Institute of Geology Chinese Academy of Sciences Beijing China

STUDY of greenhouse gases in the atmosphere and soil is one of the main tasks in global changeresearch *** present,flux monitoring data of greenhouse gases discharging from soil isbeing accumulated,but scientists understand little about greenhouse gases within soil,es-pecially in deeper *** are widely distributed loess sediments of great thickness

关键词： Co2 CH4 n2o loess Weinan.

nitrogen and oxygen isotope budget balance in tropospheric n_2o

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Chinese Science Bulletin 1999年第S2期44卷 99-100页

作者： XU Wenbin~(1,2) and HonG Yetang~1 1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 2. Institute of Environment and Resources Chemistry, Zhejiang University, Hangzhou 310027, China State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Institute of Environment and Resources Chemistry Zhejiang University Hangzhou 310027 China

THK n2o is an important greenhouse gas. In the steady state the stable isotopic composition of nitrogenand oxygen in tropospheric n2o is balanced by isotopically light n2o emitted from soils and oceans andisotopically heavy n2o as return flux from the stratosphere. However, no such balance was reached incalculations given by Kim and Craig. This serious discrepancy lied in the fact that only soil and oceanic sources were considered in Kim and Craig’s calculation and n2o emission from tropical forest soil wastaken as the global soil contribution. Progress since the 1990s in identifying additional sources of atmospheric n2o as well as in the estimation from various types of soil allows us to make more realistic assessment of nitrogen and oxygen isotope balance budgets in tropospheric n2o. In this note, modification willbe proposed of atmospheric n2o nitrogen and oxygen isotope budgets to Kim and Craig’s calculation. The static balance of nitrogen and oxygen isotopes in tropospheric n2o is expressed

关键词： n2o nitrogen stable isotope oxygen stable isotope budget balance troposphere.

The potential effect of variations in climate and agricultural practice on n_2o emissions (Ⅱ)——Variations in agricultural practice

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Chinese Science Bulletin 1999年第S2期44卷 97-99页

作者： XU Wenbin~(1,2), HonG Yetang~1, CHEn Xuhui~3, LI Changsheng~4, LIn Qinghua~1 and WAnG Yu~1, 1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 2. Institute of Environment and Resources Chemistry, Zhejiang University, Hangzhou 310027, China 3. Soil and Fertilizer Institute, Guizhou Academy of Agricultural Sciences, Guiyang 550013, China 4. Institute for the Study of Earth, oceans, and Space, University of new Hampshire, Durham, USA State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Institute of Environment and Resources Chemistry Zhejiang University Hangzhou 310027 China Soil and Fertilizer Institute Guizhou Academy of Agricultural Sciences Guiyang 550013 China Institute for the Study of Earth Oceans and Space University of New Hampshire Durham NH United States

WE expanded Decomposition-Denitrification （DnDC）modeling study to systematically assess the potential effect of farming practice on n2o emission by choosing a corn-rape rotation and a soybean-winterwheat rotation field in Guizhou Province, westsouthern China, asn2o emission from subtropical agricultural soil study plots. These sensitivity studies address questions relevant to issue of how change in fanning practice might be used to mitigate emissions. Manure additions had the most pronounced impact on n2o emissions of farming practice simulatedand the influence of manure addition was nonlinear （fig. 1）. This result is consistent with previous studies for an Iowa corn field. The addition of manure remarkably elevates the level of organic carbon, enhances soil nitrogen mineralization, and increases the efficiency of n2o production. Simulated results alsoshowed that the influence of manure additions on n2o emission from soybean-winter wheat field had

关键词： n2o emission farming practice potential effect agricultural soil.

Factors controlling n_2o and CH_4 fluxes in mixed broad-leaved/Korean pine forest of Changbai Mountain, China

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Journal of Forestry Research 1999年第4期10卷 214-218页

作者：徐慧陈冠雄黄国宏韩士杰张秀君 Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110015 P.R. China

Using the closed chamber technique, the in situ measurements of n2o and CH4 fluxes was conducted in a broad-leaved Korean pine mixed forest ecosystem in Changbai Mountain, China. from June 1994 to october 1995. The relationships between fluxes (n2o and CH4) and some major environmental factors (temperature, soil water content and soil availabIe nitrogen) were studied. A significant positive correlation between nzo emission and air/soil temperature was observed, but no significant correIation was found between n2o emission and soil water content (SWC). This result showed that temperature was an important controlling factor of n2o flux. There was a significant correlation between CH4 uptake and SWC, but no significant correlation was found between CH4 uptake and temperature. This suggested SWC was an important factor controlling CH4 uptake. The very significant negative correlation between logarithmic n2o flux and soil nitrate concentration, significant negative correlation between CH4 flux and soil ammonium content were also found.

关键词： Broad-leaved/Korean pine forest n2o CH4 Flux Environmental factors

生物炭对农田土壤中氮循环及氧化亚氮产生的影响与机理

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自然科学 2023年第2期11卷 243-252页

作者：范红叶叶孝杰吴文豪王泽宇浙江树人学院生物与环境工程学院浙江杭州浙江树人学院交叉科学研究院浙江杭州

氧化亚氮(n2o)作为温室气体和臭氧层破坏者备受学者关注,其中农田土壤是非人为条件下n2o最主要的排放源。土壤中参与氮素循环的生物/非生物过程中复杂多变,探索不同路径的氮转化机制以及对n2o的贡献度有助于对n2o减排提供机理剖析。生... 详细信息

氧化亚氮(n2o)作为温室气体和臭氧层破坏者备受学者关注,其中农田土壤是非人为条件下n2o最主要的排放源。土壤中参与氮素循环的生物/非生物过程中复杂多变,探索不同路径的氮转化机制以及对n2o的贡献度有助于对n2o减排提供机理剖析。生物炭因其高孔隙度、强吸附性、化学稳定性和大阳离子交换量等优点,会对土壤中氮素的转化产生直接/间接的影响,并显著改善/恶化土壤n2o排放。因此,总结了生物炭对土壤生态系统中氮素的转化与n2o排放的研究现状,分别论述了生物炭对无机氮循环与n2o排放的影响,并从生物炭吸附、影响土壤理化性质、群落结构多样性以及关键功能基因等方面揭示了其作用机制。基于以上内容,对今后生物炭在n2o增汇减排领域的进一步理论研究和相关技术推广进行了展望。

关键词： n2o 氮循环硝态氮铵态氮生物炭

The influence of temperature on diurnal and seasonal variations of n_2o flux from agricultural soilis in Guizhou

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Chinese Science Bulletin 1999年第S2期44卷 101-102页

作者： XU Wenbin~(1,2), HonG Yetang~1, CHEn Xuhui~3, QIn Song~3 and JIAnG Taiming~3 1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 2. Institute of Environment and Resources Chemistry, Zhejiang University, Hangzhou 310027, China 3. Soil and Fertilizer Institute, Guizhou Academy of Agricultural Sciences, Guiyang 550013, China

AGRICULTURAL soils are the major anthropogenic source of n2o, and temperature is one of the importantenvironmental factors controlling production and emission of n2o from soil. This work focuses on the influence of temperature on diurnal and seasonal variations of n2o flux from subtropical agricultural *** was done by seasonal measuring n2o flux and soil temperature at a corn-rape rotation, a soybeanwinter wheat rotation and a fallow field （106°66’E, 26°50’n, 1140 m a.s.1.）, at Soil and Fertilizer Institute, Guizhou Academy of Agricultural Sciences. Available nitrogen content of above three fields wasapproximately 0.71%, organic matter content 10.6-12.0 g/kg, clay （ontent 25.6%-30.0%, and pH was about 7.5 throughout the whole experiment. Measuring period was between 20 Mar.

关键词： n2o flux temperature diurnal variation seasonal variation agricultural soil.