我国典型茶区化学氮肥施用与生产运输过程的温室气体排放量估算

基于相关统计数据和文献调研方法,估算了我国14个典型茶区中化学氮肥施用、生产及运输过程中的温室气体排放量。结果表明,化学氮肥施用导致的土壤N₂O直接排放和生产过程中的温室气体排放是茶园化学氮肥消费带来的温室气体主要排放源;14个典型茶区消费的化学氮肥产生的温室气体排放量(以CO₂排放当量计算)为16.81~344.80万t·a^-1,其中贵州、云南、湖北和四川4省的茶园消费的化学氮肥带来的温室气体排放量较高,均超过200万t·a^-1,占全部区域温室气体排放量的59.98%;单位面积温室气体排放量为3.22~9.76 t·hm^-2·a^-1,单位产量温室气体排放量为2.10~12.96 t·t^-1·a^-1、单位产值温室气体排放量0.39~1.90 t·万元^-1·a^-1;总体而言,贵州、云南、湖北、湖南和四川5省的茶园消费的化学氮肥带来的温室气体排放量、单位面积温室气体排放量、单位产量温室气体排放量和单位产值温室气体排放量较高,福建、河南省及重庆市3个茶区相对较低。在茶园化学氮肥施用量控制为300 kg·hm^-2和450 kg·hm^-2两种情景下,茶园生态系统温室气体减排总量为617.07万t·a^-1和228.94万t·a^-1,减排潜力为34.12%和12.66%,减排潜力较大的区域主要有湖北、四川、贵州、湖南和江西等5省。     

甘蔗生物能系统的温室气体减排潜能

与化石能源相比，生物能源系统一个最主要的优势是其温室气体（GHG）排放量较低。通过发电和生产乙醇，把蔗糖厂转变成生物能源厂，可以减缓气候变暖的趋势。本论文基于泰国制糖企业的现状，提出有利于减少温室气体排放量的有效措施：提高利用甘蔗废弃物（如蔗渣和蔗梢）的发电效率；同时在酒精厂将生产酒精后的废液转化成能量，也有利于温室气体的减排；最佳减排方案是用富余的蔗糖生产乙醇，与泰国目前制糖工业相比可大大减少CO2的排放量，每年减少CO2总量可达一千四百万吨。但假定甘蔗种植地来源于草地的转换，即使应用了以上措施，在土地转变过程中产生的碳债务也需要4．5—7年的时间才能被偿还。（碳债务是指由可耕地和森林转变为生产生物燃料而引起的间接排放，比起因生物燃料所得到的利益为负值，所以被形象地称为碳债务）。     

氮肥运筹和秸秆还田对麦季土壤温室气体排放的影响

为了解氮肥运筹和秸秆还田对麦田土壤温室气体排放的影响,在秸秆还田条件下设置基肥∶壮蘖肥∶拔节肥∶孕穗肥为3∶1∶3∶3(N1)、5∶1∶2∶2(N2)、7∶1∶2∶0(N3)三个氮肥运筹方式,在秸秆不还田条件下设置5∶1∶2∶2一个氮肥运筹方式(N4),采用静态暗箱-气相色谱法对不同处理下麦田土壤排放的二氧化碳(CO2)、甲烷(CH4)和氧化亚氮(N2O)进行观测,测定小麦籽粒产量,估算土壤温室气体排放强度(GHGI)和麦季全球增温潜势(GWP)。结果表明,与秸秆不还田相比,秸秆还田显著促进了麦季CH4和CO2的排放,显著降低了N2O的排放,显著提高了麦季GWP。秸秆还田条件下,不同氮肥运筹方式间CH4、CO2累积排放量和GWP差异不显著,但N3处理显著提高了N2O累积排放量,分别较N1、N2处理提高61.22%、51.92%。N1、N2处理的GHGI最低,分别较N4处理降低41.27%和39.67%,N3处理的GHGI较N4处理增加3.30%。因此,麦季秸秆还田下采用3∶1∶3∶3和5∶1∶2∶2氮肥运筹方式有显著地增产与综合减排作用,是低碳生产的合理施肥措施。     

硝化抑制剂双氰胺施用对水稻产量和温室气体排放的影响

为探究施用硝化抑制剂双氰胺对水稻产量和温室气体排放的影响,以常规粳稻品种南粳9108为供试材料进行盆栽试验,设置常规氮肥(CK)和常规氮肥配施硝化抑制剂双氰胺(DCD)2个处理。采用静态箱-气相色谱法连续监测稻田温室气体排放动态变化。结果表明,与CK相比,DCD显著提高了水稻产量(15.1%)和地上部生物量(28.4%),并且显著降低了稻田甲烷(CH₄)累积排放量(22.2%)、氧化亚氮(N₂O)累积排放量(56.0%)、综合温室效应(GWP)(24.4%)和温室气体排放强度(GHGI)(31.7%)。可见,常规氮肥配施硝化抑制剂双氰胺可以协同实现水稻丰产和稻田温室气体减排。     

防止早衰增强棉花碳蓄积能力

减少温室气体排放,即CO2减排,是世界各国共同面临的保护人类赖以生存的地球环境的长期而艰巨的任务。对我国而言,除了积极的碳减排外,更重要的是如何增加碳增汇能力,用于抵消我国承诺的温室气体减排指标。棉花碳蓄积能力是农作物中最强的,而早衰则大大降低了其碳蓄积时间和碳蓄积量。因此,如何增强棉花碳蓄积量,充分发挥其碳蓄积功能,是我国棉花生产应当考虑的。本文提出了防止早衰增强棉花碳蓄积能力的建议和早衰治理策略。     

低温室气体排放水稻品种筛选的初步研究

水稻品种是影响稻田温室气体排放的重要因素。高产低甲烷水稻品种的种植是减排稻田温室气体的潜在的重要措施。通过盆栽试验研究不同水稻品种的温室气体排放,结果表明,稻田排放的温室气体主要是甲烷,所排氧化亚氮增温潜势约为甲烷的1/60;不同水稻品种温室气体排放量差异显著;早稻品种选用陆两优996、晚稻品种选用金优139可显著减少温室气体排放。     

抓住重点开拓创新开创全省茶叶生产工作新局面

2003年福建省茶叶种植面积为13．67万hm^2，比上年的13．34万hm^2增加0．34万hm^2，总产14．92万t，比增0，59万t，毛茶总产值20亿元，比增1．18亿元。其中绿色食品茶园面积l.53万hm^2，比上年增加0．46万hm^2，产量2．3万t，比增1．1万t；有机茶园466hm^2，比增266hm^2。名优茶产量3．6万t，产值9亿元，比上年分别增加0．23万t和0．53亿元。2003年茶叶生产业务工作具有如下特点：     

稻田N_2O排放影响因素与减排研究进展

氧化亚氮(N_2O)是稻田生态系统中一种主要的温室气体,在全球温室效应中起着很大作用。本文从稻田N_2O的产生机制、影响稻田N_2O排放的主要因素以及稻田N_2O减排的技术措施等方面综述了稻田N_2O的研究进展,并对未来开展稻田N_2O排放研究提出了一些设想,以期为减少稻田温室气体排放和氮损失提供参考。     

1980～2000年玉米主产省排名位置变动情况

198 0年十强排名 1990年十强排名 1998年十强排名 2 0 0 0年十强排名山东 (82 5 5万t)吉林 (15 2 6 6万t)吉林 (192 4 7万t)山东 (14 67 5万t)河北 (663万t)山东 (12 5 2 1万t)山东 (15 5 3 6万t)河南 (10 75 0万t)辽宁 (65 3 5万t)黑龙江 (10 65 6万t)黑龙江 (1199 7万t)河北 (994 5万t)四川 (5 41万t)河南 (960 5万t)河北 (1187 2万t)吉林 (993 2万t)河南 (5 3 3万t)河北 (82 8 7万t)辽宁 (112 0 9万t)黑龙江 (790 8万t)吉林 (5 0 7万t)辽宁 (798 2万t)河南 (10 96 3万t)内蒙古 (62 9 2万t)陕西 (2 75万t)四川 (678 6万t)内蒙古…     

农业生态系统温室气体排放研究进展

农业生态系统排放中主要的温室气体有二氧化碳（CO2）、氧化亚氮（N2O）、甲烷（CH4）。温度、水分、肥料、植被、光照、耕作制度和气候因子等影响着农业生态系统温室气体的排放量。通过静态箱法和动态箱法等,可以估算农业生态系统温室气体呼吸通量及总量。     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).