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1.
干旱地区农田生态系统土壤温室气体排放机制 总被引：3，自引：0，他引：3
CO2、CH4和N2O是目前几种最主要的温室气体,在对全球气候变暖贡献中,农业作为重要的温室气体排放源对其有不可低估的作用。一般而言,旱地农田生态系统是大气CO2和N2O的排放源,黄土高原等旱地是CH4的吸收汇。CO2排放主要包括植物呼吸作用和土壤呼吸作用;CH4排放包括有机物的还原和氧化吸收两个过程;N2O排放包括硝化作用和反硝化作用两个过程。土壤微生物、土壤水分、土壤温度、土壤质地、施肥等均从不同角度影响着温室气体的释放与吸收。近些年,免耕、秸秆还田、地膜等保护性耕作技术在干旱地区农田生态系统中得到广泛应用。其中免耕可以减少CO2和N2O的排放量,增加土壤对CH4的吸收量;秸秆还田和覆膜对N2O排放的影响结果尚未统一,但秸秆还田促进CO2排 放抑制CH4吸收,而覆膜促进CH4吸收抑制CO2排放。加强且更深入更全面的研究旱地农田生态系统温室气体排放应该作为今后重点研究领域,为全球气候变暖提供更为准确的理论基础。 相似文献
2.
基于资源环境管理角度推进测土配方施肥的方法探讨 总被引：6，自引：1，他引：5
测土配方施肥技术是由传统经验施肥向科学计量施肥的转变,既能为农业生产节本增效,满足农民对合理施肥、利润最大化的需求,又能减少农业面源污染,大幅降低农业温室气体的排放量。起步于2005年的测土配方施肥项目经8年的发展,实现了由试点到巩固再到普及的历史性跨越,各地主要以不同区域、作物2条路线开展测土配方施肥技术,在全面推广测土配方施肥的过程中初步摸索出了测土配方施肥技术的应用模式,并带动了与科学施肥相关的技术推广、配肥加工、配肥产品销售服务等行业的发展,增加了相应的人才需求。但还存在推广环节薄弱、技术的农作物覆盖范围窄、撒施、表施、浅施等粗放施肥方式较为普遍等问题。因而建议今后逐步解决企业参与问题;尽快建立和完善蔬菜、果树等园艺作物的施肥技术体系,加大其测土配方施肥技术的推广力度;建立有效的技术指导、农化服务模式。土壤测试仪器设备、小配方肥研制及其针对性施用和农化服务机制等的完善,将会促进测土配方施肥技术的全覆盖以及配方肥的规模化生产,逐步以低碳农业取代传统高碳农业,切实推动农业转型的跨越性发展。运用适宜的资源与环境管理手段,引导农民自愿参与到应用测土配方施肥技术进行减排的碳交易活动中,既为高边际减排成本排放源提供全新的减排途径,也为应用测土配方施肥技术减排的农民带来了双重经济效益,从而扩大了测土配方施肥技术的推广面积,为中国农业减污减排做出巨大贡献。 相似文献
3.
为了明确尿素和秸秆添加对茶园土壤CO_2和N2O排放的影响,为茶园合理施肥提供理论依据,本研究在室内培养条件下,以华中地区红壤丘陵区茶园土壤为对象,运用静态培养系统研究方法,研究该土壤在尿素输入和作物秸秆添加后CO_2和N_2O的排放特征。培养试验共设置对照、尿素、作物秸秆和尿素+作物秸秆4种处理。结果表明:不同处理下华中地区茶园土壤CO_2和N_2O排放呈显著差异。作物秸秆添加显著提高茶园土壤CO_2的排放,作物秸秆和作物秸秆+尿素处理分别是对照的5.57和4.99倍。尿素输入显著促进茶园土壤N_2O的排放,而秸秆添加却降低N_2O的排放。对照和添加尿素处理土壤N_2O排放通量与铵态氮含量呈显著正相关关系。无秸秆添加处理土壤N_2O排放通量与硝态氮含量呈显著的相关性,而添加秸秆处理二者无显著相关关系。土壤可溶性有机碳含量对CO_2排放有显著影响,二者之间呈极显著线性正相关关系。 相似文献
4.
黑龙江省不同土地利用方式的碳排放效应及时空格局 总被引：1，自引：0，他引：1
为了研究黑龙江省不同土地利用方式的碳排放效应,利用土地利用和能源消耗等数据,建立碳排放效应测算模型,对黑龙江省1999—2008年10年间12个主要城市土地利用碳排放情况进行测算。研究结果表明：（1）1999—2008年黑龙江省土地利用碳排放量呈现波动上涨的趋势,年均增长约305.52×104 t;（2）建设用地是最主要碳源,约占总碳源的94%;林地是最主要碳汇,占总碳汇的99%;（3）黑龙江省土地利用碳排放空间差异显著,总体呈现由东南向西北递减的趋势,碳排放量高值区主要集中在哈大齐工业走廊和煤炭、石油等工业资源型城市,低值区主要集中在伊春、黑河等森工资源型城市。研究结果为黑龙江省未来低碳土地利用转变提供了参考。 相似文献
5.
Agriculture is one of the primary contributors to Pakistan's economy. However, over the last few decades, the atmospheric carbon dioxide emission has been amplified to a great extent in Pakistan. This amplification may cause climate change, global warming, and environmental mitigation in Pakistan. This paper empirically investigates the impact of CO2 emissions on the agricultural export trade of Pakistan over the period 1975–2017. Evidence suggests that climate change could be a primary cause for the decline in Pakistan's agriculture export trade; no studies have been carried out for this specific issue, particularly over time. In this paper, the empirical analysis suggests the negative coefficient of agriculture export trade with CO2 emissions subsequently decreases agriculture export trade, which leads to direct impact on Pakistan's economy. Both theoretical and empirical outcomes suggest that the adaptation of clean and green energies and technologies are the key to reduce pollution in Pakistan. Overall, the effects of carbon dioxide emissions on agriculture export trade are stronger in the long‐run dynamics, thus making the finding heterogeneous. Possible initiatives should be taken by the government of Pakistan to improve the agriculture sector and it should also introduce new policies to reduce the emissions of carbon dioxide. 相似文献
6.
S. K. Singh G. B. Badgujar V. R. Reddy D. H. Fleisher D. J. Timlin 《Journal of Agronomy and Crop Science》2013,199(6):436-448
Phosphorous deficiency in soil limits crop growth and productivity in the majority of arable lands worldwide and may moderate the growth enhancement effect of rising atmospheric carbon dioxide (CO2) concentration. To evaluate the interactive effect of these two factors on cotton (Gossypium hirsutum) growth and physiology, plants were grown in controlled environment growth chambers with three levels of phosphate (Pi) supply (0.20, 0.05 and 0.01 mm ) under ambient and elevated (400 and 800 μmol mol?1, respectively) CO2. Phosphate stress caused stunted growth and resulted in early leaf senescence with severely decreased leaf area and photosynthesis. Phosphate stress led to over 77 % reduction in total biomass across CO2 levels. There was a below‐ground (roots) shift in biomass partitioning under Pi deficiency. While tissue phosphorus (P) decreased, tissue nitrogen (N) content tended to increase under Pi deficiency. The CO2 × Pi interactions were significant on leaf area, photosynthesis and biomass accumulation. The stimulatory effect of elevated CO2 on growth and photosynthesis was reduced or highly depressed suggesting an increased sensitivity of cotton to Pi deficiency under elevated CO2. Although, tissue P and stomatal conductance were lower at elevated CO2, these did not appear to be the main causes of cotton unresponsiveness to elevated CO2 under severe Pi‐stress. The alteration in the uptake and utilization of N was suggested due to a consistent reduction (18–21 %) in the cotton plant tissue N content under elevated CO2. 相似文献
7.
Research at the biophysical level constitutes the main approach to study the path through which climate influences infectious diseases, but the influence of socioeconomic factors on climate change and the spread of infectious diseases also cannot be ignored. In the current context, with its emphasis on carbon emission reduction, countries have begun to adopt “total control and trading” methods to reduce greenhouse gas emissions. This paper is based on the monthly relevant data of various provinces and cities from 2015 to 2019, adds the moderating variable of “carbon emission trading volume” based on current research results, establishes a static model of unbalanced panel fixed effects and a dynamic panel model, and deeply analyzes the impact of climate change on infectious disease popularity and the moderating effect of the carbon trading market. The study found that climate warming, frequent precipitation, and shortened sunshine duration will lead to an increase in the number of infectious disease cases and that the “carbon emission trading volume” variable plays a negative role in the positive correlation between climate change (temperature/precipitation) and the number of infectious disease cases. There are seasonal differences, and the moderating effect in summer/autumn is more obvious than that in winter/spring. 相似文献
8.
Abstract: Will future transportation carbon dioxide (CO2) emissions per capita in Asia Pacific economies follow historical trends of the now developed world? Evidence to date is inconclusive. A comparison at similar income levels (purchasing power parity) between recent emissions in Asia Pacific countries and historical emissions in developed countries suggests diverging patterns. (A) High‐income Asia economies (Japan, Hong Kong and Singapore –‘low emitters’) exhibit lower emissions than a selected sample of seven developed countries (United States, Australia, France, the Netherlands, Italy, Sweden and United Kingdom). (B) Another set of Asian countries (South Korea and Taiwan –‘medium emitters’) follow the emissions trends of European countries, which are lower than those of Australia and the United States. (C) A third Asian group (Malaysia and Thailand –‘high emitters’) exhibit emission trends comparable to that of Australia. We describe these trends, examine their causes and extrapolate likely futures for emissions in low‐income Asia Pacific economies (China, Indonesia, Philippines and Vietnam). Although such predictions are speculative, the available evidence suggests that road CO2 emissions for Indonesia, the Philippines and Vietnam will follow those of the third group (high emitters), while those for China may follow either Group B or Group C. 相似文献
9.
Irrigation induces processes that may either decrease or increase greenhouse gas emissions from cropping systems. To estimate the net effect of irrigation on the greenhouse gas emissions, it is necessary to consider changes in the crop yields, the content of soil organic carbon and nitrous oxide emissions, as well as in emissions from the use and production of machinery and auxiliary materials. In this study the net greenhouse gas emissions of a cropping system on a sandy soil in northeast Germany were calculated based on a long-term field experiment coupled with two-year N2O flux measurements on selected plots. The cropping system comprised a rotation of potato, winter wheat, winter oil seed rape, winter rye and cocksfoot each under three nitrogen (N) fertilization intensities with and without irrigation. Total greenhouse gas emissions ranged from 452 to 3503 kg CO2-eq ha−1 and 0.09 to 1.81 kg CO2-eq kg−1 yield. Application of an adequate amount of N fertilizer led to a decrease in greenhouse gas emissions compared to zero N fertilization whereas excessive N fertilization did not result in a further decrease. Under N fertilization there were no significant differences between irrigation and non-irrigation. Increases in greenhouse gas emissions from the operation, production and maintenance of irrigation equipment were mainly offset by increases in crop yield and soil organic carbon contents. Thus, on a sandy soil under climatic conditions of north-east Germany it is possible to produce higher yields under irrigation without an increase in the yield-related greenhouse gas emissions. 相似文献
10.
畜牧业发展与低碳经济 总被引：3，自引：1，他引：2
低碳经济指的是在发展中排放最少的温室气体,同时获得整个社会最大的产出经济,它是以低能耗、低排放、低污染为基础的经济模式。低碳经济既是经济问题,又是环境问题,也是社会问题。本文就我国畜牧业的发展面临养殖业环境污染和粮食安全两大难题进行了深入剖析,指出我国畜牧养殖业必须走低碳经济之路,应通过畜禽污染废弃物的资源化利用和营养调控措施,实现节能减排;合理利用农工业废弃物资源,包括合理利用秸秆、粮油食品工业等废弃物资源,实现节粮生产,并以循环经济理念指导,大力发展循环养殖模式,实现我国畜牧业的可持续发展。同时针对当前我国畜牧业实现向低碳经济型转型存在的诸多问题,提出了应突破观念创新、科技创新和管理创新,推进低碳经济发展。 相似文献
11.
利用改进后的全球一般均衡环境模型（GTAP-E）及其6版非CO2类温室气体排放数据库,模拟了中国非CO2类温室气体减排潜力及其政策意涵。结果显示,现阶段,中国是世界上非CO2类温室气体排放最多的国家,2020年将会占到世界总排放的20%左右。其中,来自农业部门的非CO2类温室气体排放比重达到73%。未来10年,牛羊类、工业、服务行业的非CO2排放增速最快,且服务业的增速快于工业,并在2010年后超过工业排放。中国可以通过实施非CO2类温室气体减排政策,减轻二氧化碳减排的国际压力。虽然征收较高的碳税能够带来较高的非二氧化碳减排量,但是政策效率在高碳税和低碳税间差异不大。所以,在实施非二氧化碳减排碳税政策时,应该把碳税控制在一个较低的水平。 相似文献
12.
At least 88 new hydropower dams are planned between 2010 and 2030 in the lower Mekong River basin in Southeast Asia as a source of electricity with lower greenhouse gas emissions. Dams result in declines in fish populations that will need to be replaced with other sources of protein for food security. We make the first assessment of emissions should beef production substitute for lost fish in Cambodia and Laos. We assessed two sources of emissions. Replacing lost fish with beef would require as much as 12 million hectares of new pasture. Forest clearing for pastures in Cambodia and Lao PDR would initially emit between 0.859 and 3.015 giga‐tonnes of carbon dioxide equivalents (Gt CO2‐eq.). Methane emissions from additional cattle would add at least 0.0013 Gt CO2‐eq./year to Cambodia's total greenhouse gas emissions, equivalent to a 20% increase. In Laos at least 0.0005 Gt CO2‐eq./year would be released, a 4–12% increase in annual emissions. We demonstrate that activities displaced by hydropower developments could significantly increase emissions. It shows how enclosure of commons at local scales impacts upon other common pool resources at different scales, raising questions for sustainable and equitable transboundary governance. 相似文献
13.
Reducing carbon intensity (CI) is one of the core steps of climate change mitigation. This study emphasized the roles of ecological services and regional heterogeneity in determining CI. We considered heterogeneities based on geography and income and explored the roles of net primary productivity (NPP)-based carbon footprint and CI in the changes in China's CI over 2001−2015 using an extended production-theoretical decomposition analysis and matching the socio-economic data sets with NPP data from a remote sensing satellite. We found that group technological change, reflecting the effect of shrinkage or expansion of the group best practice frontier, and the potential NPP-based carbon footprint, reflecting the impact of energy-related CO2 emissions on ecological carbon absorption, are the most significant factors accounting for the increase and decrease in CI, respectively, while NPP-based CI generally accounts for the decline in CI. We further showed that the technology gap change exhibited by an invert U-shaped curve contributed to the increase in CI under geography-based heterogeneity. We advise that China's policies should be more focused on ecological factors and regional heterogeneity in regions with abundant NPP (e.g., Yunnan and Sichuan) to further reduce CI. 相似文献
14.
The agricultural sector is highly affected by climate change and it is a source of greenhouse gases. Therefore it is in charge to reduce emissions. For a development of reduction strategies, origins of emissions have to be known. On the example of sugar beet, this study identifies the main sources and gives an overview of the variety of production systems. With data from farm surveys, calculations of greenhouse gas (GHG) emissions in sugar beet cultivation in Germany are presented. Emissions due to the production and use of fertilizers and pesticides, emissions due to tillage as well as field emissions were taken into account. All emissions related to the growing of catch crops during fall before the cultivation of sugar beet were also included. The emissions are related to the yield to express intensity.The median of total GHG emissions of sugar beet cultivation in Germany for the years 2010–2012 amounted to 2626 equivalents of CO2 (CO2eq) kg ha−1 year−1 when applying mineral plus organic fertilizer and to 1782 kg ha−1 when only organic fertilizer was applied. The CO2eq emissions resulting from N fertilization exclusively were 2.5 times higher than those caused by diesel and further production factors. The absence of emissions for the production of organic fertilizers led to 12% less total CO2eq emissions compared to the use of mineral fertilizer only. But by applying organic fertilizer only, there were more emissions via the use of diesel due to larger volumes transported (126 l diesel ha−1 vs. 116 l ha−1 by applying mineral fertilizer exclusively).As there exists no official agreement about calculating CO2eq emissions in crop production yet, the authors conclude that there is still need for further research and development with the aim to improve crop cultivation and crop rotations concerning GHG emissions and the therewith related intensity. 相似文献
15.
Irene Romero Carlos Fernandez Caballero María T. Sanchez-Ballesta María I. Escribano Carmen Merodio 《Postharvest Biology and Technology》2009,54(2):118-121
We have analyzed the influence of the stage of ripeness on L-phenylalanine ammonia-lyase (PAL) gene expression, accumulation of anthocyanins and total phenolics, and on antioxidant activity in the skin of table grapes treated with 20% CO2 + 20% O2 + 60 % N2 for 3 or 6 d at low temperature (0 °C). The residual effect of high CO2 treatment after transfer to air was also studied. In early harvested grapes, neither the anthocyanin content nor the accumulation of VcPAL mRNA was affected by any of the CO2 treatments applied. However, in late harvested grapes, the duration of high CO2 treatment determined its effect and a 6 d treatment with CO2 sustained higher levels of total phenolics and anthocyanin accumulation, and VcPAL expression than observed in untreated late harvested grapes. The increased antioxidant capacity was correlated with the total amount of phenolics and anthocyanins. Conversely, in grapes treated for 3 d with CO2 the phenylpropanoid pathway did not appear to be induced and a relationship between antioxidant activity and anthocyanins was not observed. Thus, further studies are needed to identify the most important antioxidants in these treated fruit. 相似文献
16.
基于城市化角度,根据河南省1978—2015 年时间序列数据,利用协整检验、Granger 因果分析以及动态模拟分析,研究省域城市化与碳排放间的动态相关关系。结果表明：河南省城市化水平与碳排放存在高度正向相关,且二者存在长期协整关系,从长期看,城市化水平每增加1%,则碳排放量增加1.52%;其次二者之间存在单项的格兰杰因果关系,即城市化水平的提高是引起碳排放增加的原因,但碳排放却不是引起城市化提高的因素;最后,通过动态模拟分析,河南省城市化对碳排放的影响具有正向冲击效应且有一定的滞后性,但随着城市化的发展其影响上升到一定程度后趋于平缓,并起到一定的抑制增长作用。在未来河南省城市化的长期建设中要推动其对节能减排的引擎作用,建设低碳绿色城市。 相似文献
17.
M. Das P. H. Zaidi M. Pal & U. K. Sengupta 《Journal of Agronomy and Crop Science》2002,188(4):219-224
An experiment was undertaken using open‐top chambers to study the effect of CO2 enrichment on crop growth and to assess the variation related to the time of CO2 exposure. In general, enriched CO2 conditions (600 ± 50 p.p.m.) in the chamber positively affected the growth and development of mungbean (Vigna radiata), a short‐duration (60–65 days) summer pulse crop. However, there was significant variability in the effect of the crop stage/time of CO2 exposure. It was observed that high CO2 exposure at an early growth stage [0–20 days after germination (DAG)] had a larger effect than that at a later growth stage (21–40 DAG). The experiment also provided a means of assessing the short‐ and long‐term effects of elevated CO2 on the carbon exchange rate at both stages of exposure. The study revealed that the sensitivity of plants to high CO2 was more pronounced with respect to net photosynthetic rate. The overall photosynthetic activity gave greater growth and development of plants under high CO2. 相似文献
18.
Hui Li Shengqun Liu Junhong Guo Fulai Liu Fengbin Song Xiangnan Li 《Journal of Agronomy and Crop Science》2020,206(6):773-783
The transgenerational effect of elevated atmospheric CO2 concentration (e[CO2]) on low temperature response in wheat is still little investigated, through the interaction of e[CO2], and low-temperature stress has been reported in a single generation. Here, the low temperature-induced modifications of chloroplast ultrastructure and carbohydrate metabolism in wheat after four generations continuously grown under ambient CO2 concentration (a[CO2]) and e[CO2] (2014–2018) were investigated. The results indicated that the transgenerational exposure to e[CO2] increased the number of grana lamellae and the amounts of osmiophilic lipid droplets, attenuating the negative effect of low temperature on chloroplast ultrastructure. The transgenerational e[CO2] enhanced the activities of antioxidant enzymes (i.e. SOD, POD and CAT) and concentrations of osmotic substances (i.e. proline and soluble sugar), which alleviated the low temperature-induced oxidative damage to the chloroplast ultrastructure. In addition, transgenerational exposure of wheat to e[CO2] increased activities of vacInv and cwInv, while decreased fructokinase activity, which affected the sucrose metabolism in wheat leaf. These findings elucidated that transgenerational exposure to e[CO2] could improve low temperature tolerance of winter wheat, which provide novel insights to the response of wheat to future climate change. 相似文献
19.
Conservation tillage and crop rotations improve soil quality. However, the impact of these practices on greenhouse gas (GHG) emissions and crop yields is not well defined, particularly in dry climates. A rainfed 2-year field-experiment was conducted to evaluate the effect of three long-term (17–18 years) tillage systems (Conventional Tillage (CT), Minimum Tillage (MT) and No Tillage (NT)) and two cropping systems (rotational wheat (Triticum aestivum L.) preceded by fallow, and wheat in monoculture), on nitrous oxide (N2O) and methane (CH4) emissions, during two field campaigns. Soil mineral N, water-filled pore space, dissolved organic carbon (C) and grain yield were measured and yield-scaled N2O emissions, N surplus and Global Warming Potentials (GWP) were calculated. No tillage only decreased cumulative N2O losses (compared to MT/CT) during campaign 1 (the driest campaign with least fertilizer N input), while tillage did not affect CH4 oxidation. The GWP demonstrated that the enhancement of C stocks under NT caused this tillage management to decrease overall CO2 equivalent emissions. Monoculture increased N2O fluxes during campaign 2 (normal year and conventional N input) and decreased CH4 uptake, as opposed to rotational wheat. Conversely, wheat in monoculture tended to increase soil organic C stocks and therefore resulted in a lower GWP, but differences were not statistically significant. Grain yields were strongly influenced by climatic variability. The NT and CT treatments yielded most during the dry and the normal campaign, and the yield-scaled N2O emissions followed the same tendency. Minimum tillage was not an adequate tillage management considering the GWP and the yield-scaled N2O emissions (which were 39% lower in NT with respect to MT). Regarding the crop effect, wheat in rotation resulted in a 32% increase in grain yield and 31% mitigation of yield-scaled N2O emissions. Low cumulative N2O fluxes (<250 g N2O-N ha−1 campaign−1) highlighted the relevance of soil organic C and CO2 emissions from inputs and operations in rainfed semi-arid cropping systems. This study suggests that NT and crop rotation can be recommended as good agricultural practices in order to establish an optimal balance between GHGs fluxes, GWP, yield-scaled N2O emissions and N surpluses. 相似文献
20.
Summary Under phytotronic conditions investigations were made on the effect of important environmental factors, such as temperature, water and an increasing concentration of atmospheric CO2, on the hardening of young cereal plants.In all the varieties derived from the major wheat growing regions of the world the hardening process was favourably influenced by a doubling of atmospheric CO2 content, so that a significantly larger number of plants survived the frost test than for plants of the same variety raised under normal conditions.A reduction in freezing temperature and an increase in soil moisture content caused a slight reduction in survival % for varieties with excellent frost resistance and a great reduction for those with medium or poor frost resistance.Predictions suggest that in Central Europe, as the result of global climatic changes, there will be a reduction in the quantity of winter precipitation, a considerable rise in winter temperatures and an increase in atmospheric CO2 concentration. Judging by the experimental results, these changes could improve the overwintering of winter cereals; at the same time, however, a number of factors (mainly the reduction of precipitation) leading to yield losses must be expected during the vegetation period. 相似文献