广东省秸秆燃烧大气污染物及VOCs物种排放清单

基于广东省粮食产量的统计年鉴,建立了广东省2008~2016年秸秆燃烧污染物排放清单和2016年广东省秸秆燃烧VOCs物种清单,并对VOCs臭氧生成潜势进行评估.结果表明,2013~2016年广东省秸秆燃烧各大气污染物排放量较2008~2012年有所降低.这主要是由于禁止秸秆露天燃烧政策的出台及农村生活水平的提高降低了秸秆燃烧比例.2016年各类大气污染物SO_2、NO_x、NH_3、CH_4、EC、OC、NMVOC、CO和PM_(2.5)的排放量依次为2 443.7、16 187.9、6 943.8、29 174.4、3 625.5、14 830.7、65 612.6、591 613.9和49 463.0 t.稻谷秸秆燃烧是最主要的秸秆燃烧污染物来源,占据了污染物总排放量的约68.55%.污染物贡献最大的5个市分别为湛江、茂名、梅州、肇庆和韶关,约占总排放量的58.63%.2016年广东省秸秆燃烧VOCs物种排放清单中,排放量贡献前10的物种分别为:乙烯、乙醛、甲醛、苯、乙炔、丙烯、乙烷、甲苯、正丙烷和丙醛,占总VOCs量的67.91%.在VOCs物种清单的基础上估算了其臭氧生成潜势(OFP),OFP贡献前10 VOCs物种分别为:乙烯、甲醛、乙醛、丙烯、1-丁烯、丙醛、甲苯、丙烯醛、异戊二烯和丁烯醛,占总OFP量的80.83%.     

利用植被供水指数法监测干旱的研究

利用FY-1D/AVHRR数据通道1、2的反射率计算植被指数和通道4、5的亮温计算作物冠层温度,进而求出植被供水指数可监测干旱状况.本文简单介绍了利用FY-1D/AVHRR数据植被供水指数法监测生长季的干旱状况.研究表明,该方法所得结果从总体趋势看,与实际情况基本吻合.因此,植被供水指数法适用于生长季大范围的干旱监测.     

Assessing energy efficiencies and greenhouse gas emissions under bioethanol-oriented paddy rice production in northern Japan

To establish energetically and environmentally viable paddy rice-based bioethanol production systems in northern Japan, it is important to implement appropriately selected agronomic practice options during the rice cultivation step. In this context, effects of rice variety (conventional vs. high-yielding) and rice straw management (return to vs. removal from the paddy field) on energy inputs from fuels and consumption of materials, greenhouse gas emissions (fuel and material consumption-derived CO(2) emissions as well as paddy soil CH(4) and N(2)O emissions) and ethanol yields were assessed. The estimated ethanol yield from the high-yielding rice variety, "Kita-aoba" was 2.94 kL ha(-1), a 32% increase from the conventional rice variety, "Kirara 397". Under conventional rice production in northern Japan (conventional rice variety and straw returned to the paddy), raising seedlings, mechanical field operations, transportation of harvested unhulled brown rice and consumption of materials (seeds, fertilizers, biocides and agricultural machinery) amounted to 28.5 GJ ha(-1) in energy inputs. The total energy input was increased by 14% by using the high-yielding variety and straw removal, owing to increased requirements for fuels in harvesting and transporting harvested rice as well as in collecting, loading and transporting rice straw. In terms of energy efficiency, the variation among rice variety and straw management scenarios regarding rice varieties and rice straw management was small (28.5-32.6 GJ ha(-1) or 10.1-14.0 MJ L(-1)). Meanwhile, CO(2)-equivalent greenhouse gas emissions varied considerably from scenario to scenario, as straw management had significant impacts on CH(4) emissions from paddy soils. When rice straw was incorporated into the soil, total CO(2)-equivalent greenhouse gas emissions for "Kirara 397" and "Kita-aoba" were 25.5 and 28.2 Mg CO(2) ha(-1), respectively; however, these emissions were reduced notably for the two varieties when rice straw was removed from the paddy fields in an effort to mitigate CH(4) emissions. Thus, rice straw removal avers itself a key practice with respect to lessening the impacts of greenhouse gas emissions in paddy rice-based ethanol production systems in northern Japan. More crucially, the rice straw removed is available for ethanol production and generation of heat energy with a biomass boiler, all elements required for biomass-to-ethanol transformation steps including saccharification, fermentation and distillation. This indicates opportunities for further improvement in energy efficiency and reductions in greenhouse gas emissions under whole rice plant-based bioethanol production systems.     

Are soil conservation technologies “win‐win?” A case study of Anjeni in the north‐western Ethiopian highlands

This study measures the impact of fanya juu terraces on the net value of crop income in a high‐rainfall area in the Ethiopian highlands using cross‐sectional multiple plot observations. Using propensity score matching methods we find that the net value of crop income for plots with fanya juu terraces is lower than for plots without fanya juu terraces. This finding makes it difficult to avoid concluding that while the technologies might reduce soil erosion and associated off‐site effects, they do so at the expense of poor farmers in the Ethiopian highlands. Therefore, fanya juu terraces cannot be characterized as a “win‐win” measure to reduce soil erosion. New agricultural technologies need to be profitable to the farmer if they are to be adopted and sustained.     

Importance of Crop Yield in Calibrating Watershed Water Quality Simulation Tools1

Surendran Nair, Sujithkumar, Kevin W. King, Jonathan D. Witter, Brent L. Sohngen, and Norman R. Fausey, 2011. Importance of Crop Yield in Calibrating Watershed Water Quality Simulation Tools. Journal of the American Water Resources Association (JAWRA) 47(6):1285–1297. DOI: 10.1111/j.1752‐1688.2011.00570.x Abstract: Watershed‐scale water‐quality simulation tools provide a convenient and economical means to evaluate the environmental impacts of conservation practices. However, confidence in the simulation tool’s ability to accurately represent and capture the inherent variability of a watershed is dependent upon high quality input data and subsequent calibration. A four‐stage iterative and rigorous calibration procedure is outlined and demonstrated for Soil Water Analysis Tool (SWAT) using data from Upper Big Walnut Creek (UBWC) watershed in central Ohio, USA. The four stages and the sequence of their application were: (1) parameter selection, (2) hydrology calibration, (3) crop yield calibration, and (4) nutrient loading calibration. Following the calibration, validation was completed on a 10 year period. Nash‐Sutcliffe efficiencies for streamflow over the validation period were 0.5 for daily, 0.86 for monthly, and 0.87 for annual. Prediction efficiencies for crop yields during the validation period were 0.69 for corn, 0.54 for soybeans, and 0.61 for wheat. Nitrogen loading prediction efficiency was 0.66. Compared to traditional calibration approaches (no crop yield calibration), the four‐stage approach (with crop yield calibration) produced improved prediction efficiencies, especially for nutrient balances.     

华北地区几种冬闲覆盖作物碳氮蓄积及其对土壤理化性质的影响

充分利用华北地区冬季空闲耕地及光热资源,以冬闲耕地为对照,研究二月兰（Orychophragmus violaceus）、毛苕（Vicia uillosa Roth.）、黑麦草（Secale cereale L.）、草木樨（Melilotus officinalis）、紫花苜蓿（Medicago satiua L.）5种不同冬闲覆盖作物地上部、地下部以及总碳、氮的蓄积量及其对土壤理化性质的影响。结果表明：5种覆盖作物总干物质质量在4.6-8.82 t.hm-2之间,是冬闲田干物质质量的1.6-3.1倍。5种覆盖作物全碳蓄积量在1.80-3.14 t.hm-2之间,是冬闲田碳蓄积量的1.9-3.3倍。与对照相比,各覆盖处理均明显提高氮素蓄积,尤以苜蓿最佳,达到了202.8 kg.hm-2,差异显著。试验选择5种肥覆盖均可提高土壤有机质质量分数（0.90-2.86 g.kg）;黑麦草覆盖可明显降低土壤容重（0.08 g.cm3）;毛苕和苜蓿栽培均可显著降低土壤pH,但同时土壤盐分有所增加;二月兰和黑麦草栽培在提高土壤水分含量方面表现最好。     

不同作物原料热裂解生物质炭对溶液中Cd2+和Pb2+的吸附特性

选择由小麦秸秆、玉米秸秆和花生壳经350~500℃热裂解制成的生物质炭,研究生物黑炭对水溶液中Cd2+和Pb2+的吸附特性,分析了pH值、吸附时间、溶液初始质量浓度、生物质炭粒径和投加量对吸附效果的影响。结果表明:生物质炭对Cd2+和Pb2+的吸附约10 min即达平衡;3种生物质炭对Cd2+和Pb2+的等温吸附均可用Langmuir方程和Freundlich方程拟合,玉米秸秆炭对Cd2+和Pb2+的最大吸附量远大于小麦秸秆炭和花生壳炭;在生物黑炭投加量为150 mg(6 g.L-1)时,3种生物黑炭对溶液Cd2+的去除率均在90%以上,玉米秸秆炭对溶液Pb2+的去除率达90.30%,而小麦秸秆炭和花生壳炭的去除率仅为52%和47%,玉米秸秆炭有望成为处理重金属污染废水的新型吸附材料。     

秸秆焚烧导致南京及周边地区2次空气污染事件的成因比较

从天气形势、卫星遥感火点监测、物理量诊断和后向轨迹模拟等方面分析了2008和2010年秸秆焚烧导致南京及周边地区空气污染事件过程的异同点。结果表明,2008年污染过程受大气底层切变线的控制,2010年污染过程受高压天气形势的控制;2008年火点仅出现在江苏地区,而2010年江苏、安徽和浙江地区均有出现;2008年大气底层气流为弱上升运动,导致高浓度的污染,2010年因受下沉气流控制而导致大范围的污染;2008年污染物来源为江苏地区,2010年则受江苏和安徽地区火点的共同影响,这些差异导致2次污染过程影响的范围和强度有所不同。     

不同种植制度对稻田旱作季节CH_4和N_2O排放的影响

通过大田试验研究了稻田旱作季节几种典型种植制度对CH4和N2O排放的影响,包括休闲(fallow)、油菜对照(OR-ck)、小麦对照(W-ck)、油菜施N(OR-N)和小麦施N(W-N)5个处理。试验结果表明,稻田旱作季节N2O排放明显,CH4排放量较低,甚至表现为弱的CH4汇。稻田旱作季节N2O排放除受到N肥和种植制度影响外,还受土壤含水量影响,施N处理显著促进了N2O排放,降雨后N2O排放明显。小麦和油菜施N处理N2O平均排放通量分别为18.51和13.47μg.m-2.h-1,季节累积排放量分别为87.31和59.48 mg.m-2,均显著高于对照和休闲处理。不同作物种类间N2O平均排放通量无显著差异,N2O季节累积排放量则表现为小麦显著高于油菜。各处理综合温室效应(100 a)依次为:OR-NW-NW-ckfallowOR-ck。各施N处理综合温室效应以N2O为主,但各无N处理则以CH4为主,也不容忽视。     

亚热带和温带生态条件下水稻生长速率和产量的相关性研究

在亚热带生态环境下的云南省宾川县和温带环境下的韩国水原市,2002和2003年对中国和韩国筛选出的4个水稻（Oryza sativa）高产品种进行了生长速率和产量的相关性研究,结果表明：在亚热带和温带的两种生态条件下水稻品种的叶面积指数和收获指数相近,但亚热带生态条件下实际产量和生长速率分别比温带条件下高3．06t·hm^-2和7．09g·m^-2·d^-1,产量高50．75％和生长速率高58．22％,差异达极显著水平。在亚热带条件下,移栽到移栽后20d、孕穗到抽穗的生长速率的增加能极显著提高水稻产量,以移栽到移栽后20d的生长速率影响最大,抽穗后20d生长速率的增加能增加水稻产量,但不显著。在施肥比例,基肥：分蘖肥：孕穗肥：穗肥：O％：50％：30％：20％的氮肥施用方式和稀植（30cmx14cm）条件下获得该生态区的最高产量和最大生长速率,分别为9．26t·hm^-2、19．53g·m^-2·d^-1;在温带条件下,移栽到抽穗的生长速率的增加能显著提高水稻产量,以移栽后21d到孕穗的生长速率影响最大,抽穗后20d生长速率的增加反而减低水稻产量,但不显著,氮肥施用方式基肥：分蘖肥：孕穗肥：穗肥=50％：20％：30％：0％和密植（20cm×14cm）条件下获得该生态区的最高产量和最大生长速率,分别为6．31t·hm^-2、12．00g·m^-2·d^-1。