This material is based upon work supported by the National Science Foundation under Grant Number 1215858, by the US Department of Agriculture under Grant Number 2013-68002-20525, and by the US Department of Energy Great Lakes Bioenergy Research Center &#8211; DOE BER Office of Science (DE-FC02-07ER64494) and DOE OBP Office of Energy Efficiency and Renewable Energy (DE-AC05-76RL01830). In-field video and images were recorded at the Wisconsin Integrated Cropping System Trial project of the University of Wisconsin&#8211;Madison. The authors are grateful to Ryan Curtin for skillful videography and editing.

1，硐室施工和安装锚<ol><li>设计和构建腔 - 每一个组成，其插入到土壤并在磁通测量被放置在锚的顶部上的盖子的锚 - 满足试验要求。 <ol><li>在设计室的形状和大小，考虑空间因素如作物行距，化肥或有机肥带，和株高。因为锚土壤表面上的突起可以促进小气候效应及积水，考虑具有盖子坐低到土壤表面的可能。因为腔室高度和检测灵敏度之间存在折衷，设计的盖，以尽可能短，是可行的，所研究的系统。 </li><li>建立的坚固，非反应性材料室，如不锈钢或PVC，并包括一种机制，用于密封所述盖体上的锚。绝缘盖，盖上浅色或反光材料，以防止热量积聚在测量。包括隔膜，使样品的采集和通风管，以防止室的部署和样品拆卸过程中压力扰动。如需更多详细信息请参考材料表，帕金和Venterea 8，和克拉夫等[10]。 </li></ol></li><li>至少1天前取样，安装室锚在土壤中的所需站点。安装方法将取决于腔室的设计，但在一般情况下，即使应用压力在所有点使得锚不翘曲或扭曲的土壤结构。沉锚的2.5-13厘米，取决于土壤类型，部署时间和室容积6,11的深度。留下尽可能少（不超过5厘米）突出到土壤表面以上。 </li></ol> 2，校准和实验设计注:在开始实验，请按照下列步骤来确定一个合适的采样时间过程，使数据被装配到适当的线性或非线性的磁通模型（参见Parkin 等人 12）。这将需要使用在步骤3-5（现场采样，样品分析和数据分析）中描述的技术。最佳时机是两个系统进行研究和腔室所使用的尺寸的函数。一些试验和错误可能参与。见Venterea 13替代方法。 <ol><li>标定取样和分析<ol><li>在预期产生比较高的痕量气体通量的环境或管理条件下，进行密集采样按照第3条所述的技术。使用紧密间隔的采样时间点，填充时间序列比将被视为典型的持续时间较长。通过抽样从几个有代表性的商会开始在5-10个多小时的过程中均匀分布的时间点。 </li><li>用气相色谱法以下第4分析样品。 </li></ol></li><li>校准Interpretati上<ol><li>对于每一个校准的时间序列和每种气体的利益，情节时间由浓度。 </li><li>验证通量率都在预期范围的高端。见第5节对通量计算。请参考故障排除提示2.3节。 </li><li>检查图形为非线性的迹象，或者更具体地说，plateauing气体的浓度随着时间的推移。 注意:在该浓度开始由气体种类对高原是不同的，并且是气体的生产或消耗的土壤内的速率，气体在腔室顶部空间中的浓度，这两个区域之间的扩散的功能的要点。因此，强烈受到室高度，用更短的腔高原之前产生更短的时间。 </li><li>使用校准设置，以确定实验系统最优室部署时间。如果线性回归将在数据分析中使用（如这里的第5节），选择时机是保持尽可能接近线性重lationship尽可能的时间和浓度的感兴趣的所有气体/系统之间，同时允许一个最小3，优选为4的，时间序列6内的采样次数。对于用于CO 2和N 2 O测量，时间序列腔10-30厘米高的范围通常为20-60分钟8,14。 </li></ol></li><li>校准故障排除<ol><li>如果有低分化和/或难以挑剔的线性或高原，使用更严格的校准时间点或更长的校​​准时间序列，并检查浓度范围内检测限。对于通量率较低，在积累率的降低可能不会被测试的时间框架内观察到。这不应该引起关注。 </li><li>如果通量是不是在预期的实验范围的高端，重复校准，改变治疗或环境条件诱导高通量（通过施肥和灌溉，例如）。另外，我们E的至少4个时间点中的实验设计，使得如果实验通量高于校准和plateauing期间观察到的显著更高确实发生，稍后的时间点，可以在保持线性回归至少3个时间点排除。曲线回归的方法也可以采用。 </li></ol></li><li>实验设计<ol><li>根据在第2.2.4节确定的最佳时机，制定一个总体抽样计划以捕捉所有相关网站，治疗和/或重复，并允许移动通过室网站人员有效。如果需要的话，隔膜腔室网站成几个"回合"进行采样一前一后。 <ol><li>如果测量结果将被视为代表了一整天，样品在一天的时间当气温适中相对于日常极端。在典型的温带作物系统，理想的窗口中后期，早晨。 </li><li>如果样品被收集在连续两轮时，小心不要被在每天的同一时间重复取样相同的处理引入的偏差。构建完善了重复的块，而不是治疗，通过治疗。 </li><li>包括时间，采取无论是在两轮或之前/之后（如适用）任何必要的辅助措施。 （见典型的配套措施3.3节。） </li><li>可选，包括时间收集空气样本中的非线性通量模型的使用，或作为原料的近似值（时间为零，"T 0"）浓度（此处不作讨论）的。 </li><li>任选地，包括时间，用于加载的参考气体到小瓶中在采样的时间来评估取样和分析之间可能的样品降解。看到帕金和Venterea 8样品储存注意事项。 </li></ol></li><li>确定通量测量的频率，是否适用于研究目的。这个范围可以从一个单一的测量吨Ø每天，数月或数年的过程中每周或定期测量。请参阅罗切特等人对14的实验设计方面的考虑进行了深入探讨。 </li><li>如果样本被收集在寒冷条件下，计划列入的加热装置，如热敷带小瓶，防止隔变脆的。 </li></ol></li></ol> 3，现场取样注:在每个取样日期，遵循既定在2.4节的抽样方案，使用下面描述的技术。设备和样品量可以根据所采用的收集和传输方法和样品所需要的气相色谱分析8金额有所不同。该协议利用5.9毫升收集瓶和30毫升注射器，用样品转移的冲洗方法。见讨论的替代方法。 <ol><li>准备<ol><li>如果从每回合多室取样，准备的时间点参考资料，希望能帮rence网格（ 见图2）可以轻松地跟踪何时何地品尝。另外，安排采样时，记录每个时间点。 </li><li>预标签，并安排最大效率和混乱的可能性最小采样过程中收集瓶。 </li><li>为了采样过程中节省时间，请事先准备好所有的材料和设备。包括任何可能破坏或很容易丢失（针头，注射器，旋塞等），并将其放置在一个随身携带的手提包，水桶或其他容器演员。 </li><li>准备记录任何延迟的时间点可能会发生因设备故障或其他不可预见的情况，并且可以在数据分析，通过调整具有一定的采样所需的时间很容易纠正。 </li></ol></li><li>样品采集<ol><li>连接和密封腔盖的预装室锚，并启动秒表。这是T 0。 </li><li>立即密封盖子后Ç从相邻的腔室中的位置ollect的环境空气样品，在腔室顶部的近似高度:用空30毫升注射器装有一个针和活栓在所述打开位置，绘制在30ml空气样品，并关闭旋塞阀。这是对T 0的样本。另外，搭T 0从样品室6。 注:权衡两种方法之间存在 - 评价空间（离现场或外部微气候对外部样本）与时间（盖子封闭和样品采集之间的延迟内样本）的考虑和确定最合适的技术所使用的设备和系统正在研究中。 </li><li>用注射器针头，刺破，已经有另一个针戳通过隔膜的边缘附近的一个5.9毫升收集瓶的隔膜。 </li><li>打开注射器活塞注入大约20毫升样品放入小瓶（这将导致的以前的内容小瓶通过额外的针被开除，由样品代替）。 </li><li>在一个平滑的运动，移除额外的针，同时继续注入尽可能多的剩余的样品（约10ml）中的可能的，轻微超额加压小瓶，以确保样品的完整性，并允许多个样品的分析，如果需要8。 </li><li>关闭活塞，并从隔撤出注射器针头。打开小瓶装满颠倒从悬空小瓶区分。 </li><li>继续下一个腔，重复步骤3.2.1-3.2.6，密封的盖子上正确的预定波0的时间点。 </li><li>继续重复步骤3.2.1-3.2.7，直到在圆室都已经封存和T 0的样本被收集。 </li><li>返回到所述第一腔室中。 </li><li>随着时间接近10秒，直到T 1来说，刺穿隔膜腔室顶部的注射器针头。 </li><li>在t 1，机智的10秒的范围内从室内hdraw 30ml的空气样品，并关闭水龙头。从隔室中取出注射器针头。 </li><li>将样品转移到收集瓶以下步骤3.2.3-3.2.6。 </li><li>继续收集样本以下步骤3.2.10-3.2.12，根据既定的2.4节中的采样方案。 </li></ol></li><li>配套措施<ol><li>为了气体的浓度转换为质量，测量空气温度在取样时间。根据研究目标，记录或执行其他配套措施，如在每个位置和/或时间，日降雨量，土壤容重，土壤硝态氮和铵浓度等土壤温度和土壤水分含量的各种方法的存在是为了获取这些措施 - 遵循标准协议。 </li><li>或者，搜集已知浓度的环境空气样品和/或负载领域的标准装到小瓶中，评估环境温室气体浓度和潜在的存储小瓶降解我n个采样和分析期间（见第2.4.1.4和2.4.1.5）。 </li></ol></li></ol> 4，样品分析<ol><li>确定感兴趣的气体的各样品的浓度用气相色谱法，使用的设备配有一个电子捕获检测器为N 2 O，红外气体分析仪或热导检测器的CO 2，而对于CH 4的火焰电离检测器。 注:关键是要获得访问该正确配置了温室气体的分析，具有足够的可用运行时间的工具。原则和气相色谱的方法在别处5,15,16说明。 </li><li>用理想气体定律微量气体浓度转换为体积质量: </li></ol> PV = NRT 其中P =压力V =容积中，n =气体，R =气体常数，和T =温度的摩尔数。因此: <img alt="式（1）"FO:内容宽度="4英寸"SRC ="/ files/ftp_upload/52110/52110eq1.jpg"宽度="400"/&gt; 5。数据分析<ol><li>对于每一个时间序列，剧情时间由浓度和评估线性度。评价使用拟合优度或通过视觉检查，但不包括后面的时间点表示从进一步分析高原的迹象。用最少的三个时间点包括T 0的通量计算（T 0，T 1，T 2 ......）。建立一致的协议，并拒绝任何时间序列不符合该协议的标准线性度。看到帕金和Venterea 8错误，偏差，方差通量计算进行了深入探讨。 </li><li>进行线性回归。 </li><li>使用回归的斜率来计算流量: </li></ol> F =秒•V•A -1 其中，F =通量，S =斜率的回归，V =室容积，且A =室区域。因此: <img alt="公式2" fo:content-width="1.3in" src="/files/ftp_upload/52110/52110eq2.jpg" width="130" />注:请参阅讨论与帕金等[12]对非线性方法通量计算。

<ol><li>Myhre, G., et al. Anthropogenic and Natural Radiative Forcing. In: Climate Change 2013: The Physical Science Basis. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aMyhre%2C+G+%22Contribution+of+Working+Group+I+to+the+Fifth+Assessment+Report+of+the+Intergovernmental+Panel+on+Climate+Change%22">Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change</a>. Stocker, T. F. , 8, Cambridge University Press. Cambridge, UK. (2013).</li>
<li>Denmead, O. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Approaches+to+measuring+fluxes+of+methane+and+nitrous+oxide+between+landscapes+and+the+atmosphere%5BTitle%5D)+AND+%22Plant+and+Soil%22%5BJournal%5D)">Approaches to measuring fluxes of methane and nitrous oxide between landscapes and the atmosphere.</a> Plant and Soil. 309 (1-2), 5-24 (2008).</li>
<li>Smith, K. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Micrometeorological+and+chamber+methods+for+measurement+of+nitrous+oxide+fluxes+between+soils+and+the+atmosphere%3A+Overview+and+conclusions%5BTitle%5D)+AND+%22Journal+of+Geophysical+Research%3A+Atmospheres%22%5BJournal%5D)">Micrometeorological and chamber methods for measurement of nitrous oxide fluxes between soils and the atmosphere: Overview and conclusions.</a> Journal of Geophysical Research: Atmospheres. 99 (1984-2012), 16541-16548 (1984).</li>
<li>Bouwman, A. F., Boumans, L. J. M., Batjes, N. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Emissions+of+N2O+and+NO+from+fertilized+fields%3A+Summary+of+available+measurement+data%5BTitle%5D)+AND+%22Global+Biogeochemical+Cycles%22%5BJournal%5D)">Emissions of N2O and NO from fertilized fields: Summary of available measurement data.</a> Global Biogeochemical Cycles. 16 (4), 1058(2002).</li>
<li>Hensen, A., Skiba, U., Famulari, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Low+cost+and+state+of+the+art+methods+to+measure+nitrous+oxide+emissions%5BTitle%5D)+AND+%22Environmental+Research+Letters%22%5BJournal%5D)">Low cost and state of the art methods to measure nitrous oxide emissions.</a> Environmental Research Letters. 8 (2), 025022(2013).</li>
<li>Rochette, P., Eriksen-Hamel, N. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Chamber+Measurements+of+Soil+Nitrous+Oxide+Flux%3A+Are+Absolute+Values+Reliable%5BTitle%5D)+AND+%22Soil+Science+Society+of+America+Journal%22%5BJournal%5D)">Chamber Measurements of Soil Nitrous Oxide Flux: Are Absolute Values Reliable.</a> Soil Science Society of America Journal. 72 (2), 331(2008).</li>
<li>Robertson, G. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Greenhouse+Gases+in+Intensive+Agriculture%3A+Contributions+of+Individual+Gases+to+the+Radiative+Forcing+of+the+Atmosphere%5BTitle%5D)+AND+%22Science%22%5BJournal%5D)">Greenhouse Gases in Intensive Agriculture: Contributions of Individual Gases to the Radiative Forcing of the Atmosphere.</a> Science. 289 (5486), 1922-1925 (2000).</li>
<li>Parkin, T. B., Venterea, R. T. Chamber-Based Trace Gas Flux Measurements. In: Sampling Protocols. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aParkin%2C+TB+%22http%3A%2F%2Fwww.ars.usda.gov%2Fresearch%2FGRACEnet%22">http://www.ars.usda.gov/research/GRACEnet</a>. Follet, R. F. 3 (1), 3-39 (2010).</li>
<li>Klein, C., Harvey, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Nitrous+Oxide+Chamber+Methodology+Guidelines%5BTitle%5D)+AND+%22Ministry+for+Primary+Industries%22%5BJournal%5D)">Nitrous Oxide Chamber Methodology Guidelines.</a> Ministry for Primary Industries. , Wellington, UK. 1-146 (2013).</li>
<li>Clough, T. J., Rochette, P., Thomas, S. M., Pihlatie, M., Christiansen, J. R., Thorman, R. E. Chamber Design. In: Nitrous Oxide Chamber Methodology Guidelines. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aClough%2C+TJ+%22Ministry+for+Primary+Industries%22">Ministry for Primary Industries</a>. deKlein, C., Harvey, M. , 2, Wellington, UK. (2013).</li>
<li>Hutchinson, G. L., Livingston, G. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Vents+and+seals+in+non-steady-state+chambers+used+for+measuring+gas+exchange+between+soil+and+the+atmosphere%5BTitle%5D)+AND+%22European+Journal+of+Soil+Science%22%5BJournal%5D)">Vents and seals in non-steady-state chambers used for measuring gas exchange between soil and the atmosphere.</a> European Journal of Soil Science. 52 (4), 675-682 (2001).</li>
<li>Parkin, T. B., Venterea, R. T., Hargreaves, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Calculating+the+Detection+Limits+of+Chamber-based+Soil+Greenhouse+Gas+Flux+Measurements%5BTitle%5D)+AND+%22Journal+of+Environment+Quality%22%5BJournal%5D)">Calculating the Detection Limits of Chamber-based Soil Greenhouse Gas Flux Measurements.</a> Journal of Environment Quality. 41 (3), 705(2012).</li>
<li>Venterea, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Simplified+Method+for+Quantifying+Theoretical+Underestimation+of+Chamber-Based+Trace+Gas+Fluxes%5BTitle%5D)+AND+%22Journal+of+Environment+Quality%22%5BJournal%5D)">Simplified Method for Quantifying Theoretical Underestimation of Chamber-Based Trace Gas Fluxes.</a> Journal of Environment Quality. 39 (1), 126(2010).</li>
<li>Rochette, P., Chadwick, D. R., de Klein, C. Deployment Protocol. In: Nitrous Oxide Chamber Methodolog Guidelines. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aRochette%2C+P+%22Ministry+for+Primary+Industries%22">Ministry for Primary Industries</a>. deKlein, C., Harvey, M. (3), Wellington, UK. (2013).</li>
<li><a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Fundamentals+of+Gas+Chromatography%5BTitle%5D)+AND+%22Agilent+Technologies%2C+Inc%22%5BJournal%5D)">Fundamentals of Gas Chromatography.</a> Agilent Technologies, Inc. , 1-60 (2002).</li>
<li>Holland, E. A., Robertson, G. P., Greenberg, J., Groffman, P. M., Boone, R. D., Gosz, J. R. Soil CO2, N2O, and CH4 Exchange. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aHolland%2C+EA+%22Standard+Soil+Methods+for+Long-Term+Ecological+Research%22">Standard Soil Methods for Long-Term Ecological Research</a>. Robertson, G. P., Coleman, D. C., Bledsoe, C. S. , Oxford University Press. New York, NY. (1999).</li>
<li>Venterea, R. T., Burger, M., Spokas, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Nitrogen+Oxide+and+Methane+Emissions+under+Varying+Tillage+and+Fertilizer+Management%5BTitle%5D)+AND+%22Journal+of+Environment+Quality%22%5BJournal%5D)">Nitrogen Oxide and Methane Emissions under Varying Tillage and Fertilizer Management.</a> Journal of Environment Quality. 34 (5), 1467(2005).</li>
<li>Hutchinson, G. L., Mosier, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Improved+soil+cover+method+for+field+measurement+of+nitrous+oxide+fluxes%5BTitle%5D)+AND+%22Soil+Science+Society+of+America+Journal%22%5BJournal%5D)">Improved soil cover method for field measurement of nitrous oxide fluxes.</a> Soil Science Society of America Journal. 45 (2), 311-316 (1981).</li>
<li>Pedersen, A. R., Petersen, S. O., Vinther, F. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Stochastic+diffusion+model+for+estimating+trace+gas+emissions+with+static+chambers%5BTitle%5D)+AND+%22Soil+Science+Society+of+America+Journal%22%5BJournal%5D)">Stochastic diffusion model for estimating trace gas emissions with static chambers.</a> Soil Science Society of America Journal. 65, 49-58 (2001).</li>
<li>Pedersen, A. R., Peterson, S. O., Schelde, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+comprehensive+approach+to+soil-atmosphere+trace-gas+flux+estimation+with+static+chambers%5BTitle%5D)+AND+%22European+Journal+of+Soil+Science%22%5BJournal%5D)">A comprehensive approach to soil-atmosphere trace-gas flux estimation with static chambers.</a> European Journal of Soil Science. 61, 888-902 (2010).</li>
<li>Wagner, S. W., Reicosky, D. C., Alessi, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Regression+models+for+calculating+gas+fluxes+measured+with+a+closed+chamber%5BTitle%5D)+AND+%22Agronomy+Journal%22%5BJournal%5D)">Regression models for calculating gas fluxes measured with a closed chamber.</a> Agronomy Journal. 89, 279-284 (1997).</li>
<li>Livingston, G. P., Hutchinson, G. L., Spartalian, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Trace+gas+emission+in+chambers%5BTitle%5D)+AND+%22Soil+Science+Society+of+America+Journal%22%5BJournal%5D)">Trace gas emission in chambers.</a> Soil Science Society of America Journal. 70, 1459-1469 (2006).</li>
<li>Venterea, R. T., Parkin, T. B., Cardenas, L., Petersen, S. O., Pedersen, A. R. Data Analysis Considerations. In: Nitrous Oxide Chamber Methodology Guidelines. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aVenterea%2C+RT+%22Ministry+for+Primary+Industries%22">Ministry for Primary Industries</a>. deKlein, C., Harvey, M. (6), Wellington, UK. (2013).</li>
<li>Grace, P., van der Weerden, T. J., Kelly, K., Rees, R. M., Skiba, U. M. Automated Greenhouse Gas Measurement in the Field. In: Nitrous Oxide Chamber Methodology Guidelines. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aGrace%2C+P+%22Ministry+for+Primary+Industries%22">Ministry for Primary Industries</a>. deKlein, C., Harvey, M. , 5, Wellington, UK. (2013).</li>
<li>Alfaro, M. A., Giltrap, D., Topp, C. F. E., de Klein, C. How to Report Your Experimental Data. In: Nitrous Oxide Chamber Methodology Guidelines. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aAlfaro%2C+MA+%22Ministry+for+Primary+Industries%22">Ministry for Primary Industries</a>. deKlein, C., Harvey, M. , 7, Wellington, UK. (2013).</li>
</ol>

The authors have nothing to disclose.

<html>这里所描述的静态室为基础的方法是用于从土壤系统温室气体通量的测量的有效方法。它的组成部分的相对简单性使得它特别适合于条件或系统，其中多个基础设施密集的方法是不可行的。为了生成高质量的数据，但是，静态箱的方法，必须进行严格的注重实验设计6。必须考虑的一个重要的考虑因素是土壤气体通量的空间变异，这可能会导致高变异重复室为基础的测量中。在设计的实验，因此，它是重要的，包括足够的重复，以进行统计分析提供足够的电力。权衡可能的，可以在维持足够的复制，并至少每处理4个重复的一般准则14进行研究处理的数量之间存在。 ontent"&gt;如果测量的通量将被用于估算每天的排放量，空气温度，土壤温度和气体排放日变化必须被考虑在内。如果研究目标要求的测量将在早盘中段时获得的温度反映日常平均值，采样限制窗口可能会影响，可以切实进行监控室的数量。进行评估另外一个考虑是冲击，列入植物根系和地上部生物量或排除将会对气体通量。相对商会放置植物组织会影响通量数据的解释，特别是在二氧化碳这里不仅微生物呼吸也根冠呼吸作用和光合作用必须是适当的平衡，对于这些因素的更多讨论，请参阅帕 ​​金和Venterea 8的情况下。 如前面所指出的，这一方法存在许多差异，包括腔室设计和采样体积。一种这样的变化是在采用注射器和收集瓶之间传送样品的方法。这里所描述的技术首先冲收集瓶与样品填充小瓶正压5之前。一种更常用的方法是样品从注射器转移到已用真空泵预抽空小瓶中，并采用非真空瓶无冲洗还报道了8,17。另一个显著地步了一系列的办法是存在于数据分析和最适合所研究的系统的通量模型的选择。除了这里描述的线性回归法，非线性模型也可以采用，尤其是当使用较长的部署时间。这些模型包括由Hutchinson和莫西尔18开发的算法和推导它们的19,20，由Wagner 等 21所述的二次程序，以及非稳定由利文斯顿等人描述22国家扩散通量估算。对于非线性通量模型的详细讨论，请参阅Parkin 等人 12 Venterea 等[23]。 方法类似于静态箱的方法包括使用流量通过测量系统的与傅里叶变换红外（FTIR）光谱法作为备用注射器，采样和气相色谱法，以及腔室盖和采样的自动化通过各种手段。自动化系统启用更频繁的测量，减少了人员，而且还需要额外的基础设施投资。格雷斯等 24提供的选择和权衡自动化室为基础的N 2 O测量了广泛的总结。 从管理的和自然系统是很重要的通知基于过程的模型，了解管理EAST的影响，温室气体通量表征NT的做法，并告知减灾战略，并支持全球会计和气候变化模型。因此，虽然个别研究是信息在当地的规模，多少额外的价值是通过促进，并且从，对景观和大气之间的气体交换知识的一个全球性机构绘制而得。这是关键，因此，这些数据被收集和报告，确保长寿和互操作性与更广泛的知识基础的方法。这包括以下最佳实践，以确保数据质量，以及收集的配套措施和元数据的综合报告，以允许扩展名的调查结果超出了离散研究。可从GRACEnet项目和GRA 25数据汇报优秀的指引。

Understanding the contributions of both human activities and natural systems to radiative properties of the atmosphere is an area of critical importance as we strive to mitigate anthropogenic contributions to the greenhouse effect. In addition to carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) are also potent GHGs, accounting for an estimated 7% and 19% of global warming, respectively, with the majority of emissions coming from landscape sources1,2. These range from managed systems such as agricultural fields, rice paddies, and landfills, to natural systems such as forest floors, wetlands, and termite mounds. Accurate measurement, supporting well-informed modeling of such landscape-based emissions is critical in order to understand the drivers of climate change as well as to identify mitigation opportunities.
A variety of greenhouse gas measurement strategies exist, each with their own strengths and weaknesses2-5. Mass balance techniques rely on wind-based dispersion of gases and are suited to measurement of flux from small, well-defined sources such as landfills and animal paddocks. Micrometeorological approaches such as eddy covariance are based on real-time direct measurement of vertical gas flux, and can provide direct measurements over large areas. However, homogeneity in source topography is an implicit assumption (in that measurements yield a mean for the area under study), and costly infrastructure can limit deployment possibilities. Finally, chamber-based methods focus on change in gas concentration at the soil surface by sampling from a restricted above ground headspace. They allow measurements to be obtained from small areas and numerous treatments, but are subject to high coefficients of variation due to spatial variation in soil gas flux.
Here we discuss the most prevalent and easily implemented form of chamber-based measurement, utilizing the type of closed chambers without air flow-through commonly referred to as &#8220;static&#8221; or &#8220;non-steady-state non-flow-through&#8221; chambers. In this approach, gas emissions from the soil surface are trapped within a vented chamber, and rates of flux are determined by measuring the change in gas concentration over time within the chamber headspace. The static chamber technique has been widely deployed across both managed and natural landscapes and underpins the bulk of data reporting soil-based flux of greenhouse gases, particularly N2O6,7. It is ideally suited to the study of small experimental plots, diverse sites over variable terrain, or in other situations where multiple distinct locations must be studied without significant infrastructure investments. Typical experimental uses might include the exploration of alternative landscape management practices and their impact on soil-based CO2, N2O, and/or CH4 emissions, examination of landscape-based flux dynamics under artificially induced climate change scenarios such as warming and rainfall exclusion/supplementation, or the descriptive study of natural and agricultural ecosystems and subsystems.
As a critical tool in GHG measurement and flux estimation, the static chamber method has been thoroughly evaluated, and significant efforts have been made towards standardization of techniques and harmonization of data reporting4,6,8,9. Of particular note are the detailed reviews and guidelines produced by the U.S. Department of Agriculture &#8211; Agricultural Research Service&#8217;s Greenhouse gas Reduction through Agricultural Carbon Enhancement network (GRACEnet)8 and by the Global Research Alliance on Agricultural Greenhouse Gases (GRA)9. Such guidelines provide an invaluable resource and platform for coordination, as ultimately the interoperability of data from a myriad of studies is critical for scaling up local findings to global modeling, and for translating research results into viable mitigation strategies.
GRACEnet, GRA, and other reviews also highlight the fact that specific techniques in static chamber-based greenhouse gas flux measurement are extremely diverse, with significant methodological variations possible at nearly every step of the way, including chamber design, temporal and spatial deployment, sampling volumes, sample analysis, and flux calculations. The method described here presents one possible variant, while showcasing best practices and highlighting critical considerations for the generation of high quality, broadly transferrable data. It is intended to provide an accessible overview of this standardized procedure, and a platform from which to explore further nuances and variations described in the literature.

<table><tbody><tr><td>5.9 ml soda glass flat bottom 55 x 15.5 mm</td><td>Labco Limited</td><td>719W</td><td>Collection vials</td></tr><tr><td>16.5 mm screw caps with pierceable rubber septum</td><td>Labco Limited</td><td>VC309</td><td>Caps for&amp;nbsp; vials</td></tr><tr><td>90-well plastic vial rack, 17.1 mm well I.D.</td><td>Wheaton</td><td>868810</td><td>Rack for organizing vials</td></tr><tr><td>Regular bevel needles 23 G x 1&quot;</td><td>BD</td><td>305193</td><td>Needles for sample collection</td></tr><tr><td>Stopcocks with luer connections, 1-way, male slip</td><td>Cole-Parmer</td><td>EW-30600-01</td><td>Stopcocks for syringes</td></tr><tr><td>30 ml syringe, slip tip</td><td>BD</td><td>309651</td><td>Syringes for sample collection</td></tr><tr><td>Stopwatch or timer</td><td>Various</td><td>N/A</td><td>For timing field sampling</td></tr><tr><td>Stainless steel or galvanized utility pans with rim, or fabricated stainless steel or PVC chambers and lids, dimensions as appropriate to experimental system</td><td>Various</td><td>N/A</td><td>Chamber anchor and lid - bottom cut out of anchor, holes for septum and vent tubing bored in lid</td></tr><tr><td>Gray butyl stoppers 20 mm</td><td>Wheaton</td><td>W224100-173</td><td>Chamber septa for syringe sampling - insert into hole bored in lid top</td></tr><tr><td>Tygon tubing 4.0 mm I.D. x 5.6 mm O.D.</td><td>Sigma-Aldrich</td><td>Z685623</td><td>Chamber vent tubing - insert in hole bored in lid side, flush with exterior, approximately 25 cm coiled in lid interior (a 1 ml syringe tip may be used as an attachment mechanism)</td></tr><tr><td>Adhesive foam rubber tape or HDPE O-ring</td><td>Various</td><td>N/A</td><td>Chamber sealing mechanism - fastened to underside of lid rim</td></tr><tr><td>Reflective&amp;nbsp; insulation, 0.3125&quot; thickness</td><td>Lowe&#039;s</td><td>409818</td><td>Insulating and reflective coating - affix to exterior of chamber lid</td></tr><tr><td>Large metal binder clips, 2&quot; size with 1&quot; capacity, or manufactured draw latch as appropriate</td><td>Staples / McMaster</td><td>831610 (Staples) / 1863A21 (McMaster)</td><td>Lid attachment mechanism - for clamping lid to anchor during sampling</td></tr><tr><td>Gas chromatography equipment fitted with electron capture detector for nitrous oxide, infrared gas analyzer or thermal conductivity detector for carbon dioxide, flame ionization detector for methane</td><td>Various</td><td>N/A</td><td>For sample analysis</td></tr></tbody></table>

measurement of greenhouse gas flux from agricultural soils using static chambers

Measurement of greenhouse gas (GHG) fluxes between the soil and the atmosphere, in both managed and unmanaged ecosystems, is critical to understanding the biogeochemical drivers of climate change and to the development and evaluation of GHG mitigation strategies based on modulation of landscape management practices. The static chamber-based method described here is based on trapping gases emitted from the soil surface within a chamber and collecting samples from the chamber headspace at regular intervals for analysis by gas chromatography. Change in gas concentration over time is used to calculate flux. This method can be utilized to measure landscape-based flux of carbon dioxide, nitrous oxide, and methane, and to estimate differences between treatments or explore system dynamics over seasons or years. Infrastructure requirements are modest, but a comprehensive experimental design is essential. This method is easily deployed in the field, conforms to established guidelines, and produces data suitable to large-scale GHG emissions studies.

在此之前开始的一个研究项目，静态室，了解整个工作流程是非常重要的，而在硅片的组织，现场和实验室为基础的元素（ 图1）。提供精心的实验设计和系统校准（ 图2），数据分析一般是相对简单的。通量的速率被确定为使用适当的系统预先确定的磁通模型（ 图3），每个腔室和采样时间的时间回归由浓度。然而，即使下面的最佳实践，困难可能会遇到，和原始数据的质量控制是至关重要的。例如，一个腔室密封或泄漏的样品瓶失败可能会导致异常的浓度值。这些工作是通过对时间序列浓度重复目视检查（ 图4），与CO 2的时间序列常常作为特别usefu容易地识别L指示由于CO 2的通常更强大和持续的通量相比，有时可以忽略不计，接近检测限，甚至是负的N 2 O或CH 4通量。一旦数据质量得到了确认，结果可用于比较治疗之间或在一个赛季中（ 图5）气体流量动态。正如从五月和六月光通量值和误差线可以看出，造成通量的空间异质性的变化可能会显著，而且产生的通量率很高的条件下更加明显。这种变异是不寻常的，并强调了在这一技术复制足够的重视。 <img alt="图1" src="/files/ftp_upload/52110/52110fig1highres.jpg" width="600" /> 图1:工作流概述。这个协议的各种元素将开展在规划阶段，在该领域，在实验室里，和我Ñ ​​硅片。箭头表示工作流程的顺序，与腔体设计（及施工必要时）开始，并与数据分析总结。野外采样和样品分析之间的多盒/箭头代表超过一个实验的过程中多次采样日期的可能性。 <img alt="图2" src="/files/ftp_upload/52110/52110fig2highres.jpg" width="400" /> 图2样品的时机。样品的同时从多个室的集合的一个例子时序方案。商会数字显示在左边，时间点在顶部，与网格内的整分钟数列的采样时间。在这个例子中，四个单独的时间序列的各36分钟（每一个腔室）中进行，46分钟的空间内，以时间点之间的12分钟间隔内的一个序列，和腔室之间的2分钟的步行时间。对于这个假设的例子中，绥36分钟的时间序列tability会被事先标定来确定。而均匀间隔开的时间是没有必要的，它往往简化了采样方案。另外，研究人员可以单独记录每个采样时间点来确定采样间隔。 <img alt="图3" src="/files/ftp_upload/52110/52110fig3highres.jpg" width="600" /> 图3。流量计算，一个典型的静态室的时间序列，由N 2在四个时间点过了36分钟采样周期过程中进行测定ø的浓度。显示的线性回归，其中的斜率得到通量率。 <img alt="图4" src="/files/ftp_upload/52110/52110fig4highres.jpg" width="600" /> 图4。质量控制。配对时间序列从相同的一组样品，但不同的气体都显示在WHI的CH瓶泄漏已被确定通过目测（红点）。A）CO 2浓度随着时间的推移，B）N 2 O的浓度随着时间的推移。 <img alt="图5" src="/files/ftp_upload/52110/52110fig5highres.jpg" width="600" /> 从农田图5。合成的结果。N 2 O通量率在一个生长季节的过程。磁通值代表的6室中的平均值，采用四点的时间序列。误差线为标准误差。

Watch this Scientific Journal Video about Measurement of Greenhouse Gas Flux from Agricultural Soils Using Static Chambers at JoVE.com

Measurement of Greenhouse Gas Flux from Agricultural Soils Using Static Chambers

This article showcases the static chamber-based method for measurement of greenhouse gas flux from soil systems. With relatively modest infrastructure investments, measurements may be obtained from multiple treatments/locations and over timeframes ranging from hours to years.

从农业土壤使用静态钱伯斯温室气体流量测量

Measurement of greenhouse gas (GHG) fluxes between the soil and the atmosphere, in both managed and unmanaged ecosystems, is critical to understanding the ...

measurement-greenhouse-gas-flux-from-agricultural-soils-using-static

Research

Education

JoVE Core

JoVE Journal

Physics

Environment

Unit 1

The Kinetic Theory of Gases

SCIENTISTS IN ACTION

41.2K 次观看.  University of Wisconsin-Madison. This article showcases the static chamber-based method for measurement of greenhouse gas flux from soil systems. With relatively modest infrastructure investments, measurements may be obtained from multiple treatments/locations and over timeframes ranging from hours to years.

视频: Measurement of Greenhouse Gas Flux from Agricultural Soils Using Static Chambers

High-throughput Fluorometric Measurement of Potential Soil Extracellular Enzyme Activities

Microbes in soils and other environments produce extracellular enzymes to depolymerize and hydrolyze organic macromolecules so that they can be assimilated for energy and nutrients. Measuring soil microbial enzyme activity is crucial in understanding soil ecosystem functional dynamics. The general concept of the fluorescence enzyme assay is that synthetic C-, N-, or P-rich substrates bound with a fluorescent dye are added to soil samples. When intact, the labeled substrates do not fluoresce. Enzyme activity is measured as the increase in fluorescence as the fluorescent dyes are cleaved from their substrates, which allows them to fluoresce. Enzyme measurements can be expressed in units of molarity or activity. To perform this assay, soil slurries are prepared by combining soil with a pH buffer. The pH buffer (typically a 50 mM sodium acetate or 50 mM Tris buffer), is chosen for the buffer&#39;s particular acid dissociation constant (pKa) to best match the soil sample pH. The soil slurries are inoculated with a nonlimiting amount of fluorescently labeled (i.e. C-, N-, or P-rich) substrate. Using soil slurries in the assay serves to minimize limitations on enzyme and substrate diffusion. Therefore, this assay controls for differences in substrate limitation, diffusion rates, and soil pH conditions; thus detecting potential enzyme activity rates as a function of the difference in enzyme concentrations (per sample).
Fluorescence enzyme assays are typically more sensitive than spectrophotometric (i.e. colorimetric) assays,&#160;but can suffer from interference caused by impurities and the instability of many fluorescent compounds when exposed to light; so caution is required when handling fluorescent substrates. Likewise, this method only assesses potential enzyme activities under laboratory conditions when substrates are not limiting. Caution should be used when interpreting the data representing cross-site comparisons with differing temperatures or soil types, as in situ soil type and temperature can influence enzyme kinetics.

To measure potential rates of soil extracellular enzyme activities, synthetic substrates that are bound to a fluorescent dye are added to soil samples. Enzyme activity is measured as the fluorescent dye is released from the substrate by an enzyme-catalyzed reaction, where higher fluorescence indicates more substrate degradation.

潜在土壤胞外酶活性的高通量荧光测量

Microbes in soils and other environments produce extracellular enzymes to depolymerize and hydrolyze organic macromolecules so that they can be ...

科研

环境科学

The Use of an Automated System (GreenFeed) to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals

Ruminant animals (domesticated or wild) emit methane (CH4) through enteric fermentation in their digestive tract and from decomposition of manure during storage. These processes are the major sources of greenhouse gas (GHG) emissions from animal production systems. Techniques for measuring enteric CH4 vary from direct measurements (respiration chambers, which are highly accurate, but with limited applicability) to various indirect methods (sniffers, laser technology, which are practical, but with variable accuracy). The sulfur hexafluoride (SF6)&#160;tracer gas method is commonly used to measure enteric CH4 production by animal scientists and more recently, application of an Automated Head-Chamber System (AHCS) (GreenFeed, C-Lock, Inc., Rapid City, SD), which is the focus of this experiment, has been growing. AHCS is an automated system to monitor CH4 and carbon dioxide (CO2) mass fluxes from the breath of ruminant animals. In a typical AHCS operation, small quantities of baiting feed are dispensed to individual animals to lure them to AHCS multiple times daily. As the animal visits AHCS, a fan system pulls air past the animal&#8217;s muzzle into an intake manifold, and through an air collection pipe where continuous airflow rates are measured. A sub-sample of air is pumped out of the pipe into non-dispersive infra-red sensors for continuous measurement of CH4 and CO2 concentrations. Field comparisons of AHCS to respiration chambers or SF6 have demonstrated that AHCS produces repeatable and accurate CH4 emission results, provided that animal visits to AHCS are sufficient so emission estimates are representative of the diurnal rhythm of rumen gas production. Here, we demonstrate the use of AHCS to measure CO2 and CH4 fluxes from dairy cows given a control diet or a diet supplemented with technical-grade cashew nut shell liquid.

The Use of an Automated System GreenFeed to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals

Accuracy and precision of the techniques used to measure methane emissions from ruminant animals are critically important for the success of greenhouse gas mitigation efforts. This manuscript describes the principles and operation of an automated system to monitor methane and carbon dioxide mass fluxes from the breath of ruminant animals.

自动系统（绿色饲料）的用于监视肠道的甲烷和二氧化碳从反刍动物排放

Ruminant animals (domesticated or wild) emit methane (CH4) through enteric fermentation in their digestive tract and from decomposition of manure during ...

A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function

Continuing increases in atmospheric carbon dioxide concentrations (CA) mandate techniques for examining impacts on terrestrial ecosystems. Most experiments examine only two or a few levels of CA concentration and a single soil type, but if CA can be varied as a gradient from subambient to superambient concentrations on multiple soils, we can discern whether past ecosystem responses may continue linearly in the future and whether responses may vary across the landscape. The Lysimeter Carbon Dioxide Gradient Facility applies a 250 to 500 &#181;l L-1 CA gradient to Blackland prairie plant communities established on lysimeters containing clay, silty clay, and sandy soils. The gradient is created as photosynthesis by vegetation enclosed in in temperature-controlled chambers progressively depletes carbon dioxide from air flowing directionally through the chambers. Maintaining proper air flow rate, adequate photosynthetic capacity, and temperature control are critical to overcome the main limitations of the system, which are declining photosynthetic rates and increased water stress during summer. The facility is an economical alternative to other techniques of CA enrichment, successfully discerns the shape of ecosystem responses to subambient to superambient CA enrichment, and can be adapted to test for interactions of carbon dioxide with other greenhouse gases such as methane or ozone.

A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function

The Lysimeter Carbon Dioxide Gradient Facility creates a 250 to 500 &#181;l L-1 linear carbon dioxide gradient in temperature-controlled chambers housing grassland plant communities on clay, silty clay, and sandy soil monoliths. The facility is used to determine how past and future carbon dioxide levels affect grassland carbon cycling.

一个外线<sub&gt; 2</sub&gt;浓度梯度用于测试CO<sub&gt; 2</sub&gt;浓度与土壤对草地生态系统功能的影响

Continuing increases in atmospheric carbon dioxide concentrations (CA) mandate techniques for examining impacts on terrestrial ecosystems. Most ...

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses

A method is described which uses the absence of radiocarbon in industrial chemicals and fuels made from petroleum feedstocks which frequently contaminate the environment. This radiocarbon signal &#8212; or rather the absence of signal &#8212; is evenly distributed throughout a contaminant source pool (unlike an added tracer) and is not impacted by biological, chemical or physical processes (e.g., the 14C radioactive decay rate is immutable). If the fossil-derived contaminant is fully degraded to CO2, a harmless end-product, that CO2 will contain no radiocarbon. CO2 derived from natural organic matter (NOM) degradation will reflect the NOM radiocarbon content (usually &#60;30,000 years old). Given a known radiocarbon content for NOM (a site background), a two end-member mixing model can be used to determine the CO2 derived from a fossil source in a given soil gas or groundwater sample. Coupling the percent CO2 derived from the contaminant with the CO2 respiration rate provides an estimate for the total amount of contaminant degraded per unit time. Finally, determining a zone of influence (ZOI) representing the volume from which site CO2 is collected allows determining the contaminant degradation per unit time and volume. Along with estimates for total contaminant mass, this can ultimately be used to calculate time-to-remediate or otherwise used by site managers for decision-making.

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses

A protocol is described wherein CO2 mineralized from organic contaminant (derived from petroleum feedstocks) biodegradation is trapped, quantified, and analyzed for 14C content. A model is developed to determine CO2 capture zone's spatial extent. Spatial and temporal measurements allow integrating contaminant mineralization rates for predicting remediation extent and time.

测量碳为基础的污染物矿化结合使用CO<sub&gt; 2</sub&gt;助焊剂和放射性碳分析

A method is described which uses the absence of radiocarbon in industrial chemicals and fuels made from petroleum feedstocks which frequently contaminate ...

Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers

Agricultural ammonia (NH3) emissions (90% of total EU emissions) are responsible for about 45% airborne eutrophication, 31% soil acidification and 12% fine dust formation within the EU15. But NH3 emissions also mean a considerable loss of nutrients. Many studies on NH3 emission from organic and mineral fertilizer application have been performed in recent decades. Nevertheless, research related to NH3 emissions after application fertilizers is still limited in particular with respect to relationships to emissions, fertilizer type, site conditions and crop growth. Due to the variable response of crops to treatments, effects can only be validated in experimental designs including field replication for statistical testing. The dominating ammonia loss methods yielding quantitative emissions require large field areas, expensive equipment or current supply, which restricts their application in replicated field trials. This protocol describes a new methodology for the measurement of NH3 emissions on many plots linking a simple semi-quantitative measuring method used in all plots, with a quantitative method by simultaneous measurements using both methods on selected plots. As a semi-quantitative measurement method passive samplers are used. The second method is a dynamic chamber method (Dynamic Tube Method) to obtain a transfer quotient, which converts the semi-quantitative losses of the passive sampler to quantitative losses (kg nitrogen ha-1). The principle underlying this approach is that passive samplers placed in a homogeneous experimental field have the same NH3 absorption behavior under identical environmental conditions. Therefore, a transfer co-efficient obtained from single passive samplers can be used to scale the values of all passive samplers used in the same field trial. The method proved valid under a wide range of experimental conditions and is recommended to be used under conditions with bare soil or small canopies (&#60;0.3 m). Results obtained from experiments with taller plants should be treated more carefully.

Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers

Ammonia emissions are a major threat to the environment by eutrophication, soil acidification and fine particle formation and stem mainly from agricultural sources. This method allows ammonia loss measurements in replicated field trials enabling statistical analysis of emissions and of relationships between crop development and emissions.

校准被动采样 - NH多情节场测量<sub&gt; 3</sub&gt;与动态管法和被动采样的组合排放

Agricultural ammonia (NH3) emissions (90% of total EU emissions) are responsible for about 45% airborne eutrophication, 31% soil acidification and 12% ...

Assessment of Methane and Nitrous Oxide Fluxes from Paddy Field by Means of Static Closed Chambers Maintaining Plants Within Headspace

This protocol describes the measurement of greenhouse gas (GHG) emissions from paddy soils using the static closed chamber technique. This method is based on the diffusion theory. A known volume of air overlaying a defined soil area is enclosed within a parallelepiped cover (named &#34;chamber&#34;), for a defined period of time. During this enclosure period, gases (methane (CH4) and nitrous oxide (N2O)) move from soil pore air near their microbial source (i.e., methanogens, nitrifiers, denitrifiers) to the chamber headspace, following a natural concentration gradient. Fluxes are then estimated from chamber headspace concentration variations sampled at regular intervals throughout the enclosure and then analyzed with gas chromatography. Among the techniques available for GHG measurement, the static closed chamber method is suitable for plot experiments, as it does not require large homogenously treated soil areas. Furthermore, it is manageable with limited resources and can identify relationships among ecosystem properties, processes, and fluxes, especially when combined with GHG driving force measurements. Nevertheless, with respect to the micrometeorological method, it causes a minimal but still unavoidable soil disturbance, and allows a minor temporal resolution. Several phases are key to the method implementation: i) chamber design and deployment, ii) sample handling and analyses, and iii) flux estimation. Technique implementation success in paddy fields demands adjustments for field flooding during much of the cropping cycle, and for rice plant maintenance within the chamber headspace during measurements. Therefore, the additional elements to be considered with respect to the usual application of non-flooded agricultural soils consist of devices for: i) avoiding any unintended water disturbance that could overestimate fluxes, and ii) including rice plants within the chamber headspace to fully consider gases emitted through aerenchyma transportation.

The overall goal of this protocol is to measure greenhouse gas emissions from paddy fields using the static closed chamber technique. The measurement system needs specific adjustments due to the presence of both a permanent water layer in the field and of the plants within the chamber headspace.

用静止封闭室维持顶空装置对稻田甲烷和一氧化二氮通量的评价

This protocol describes the measurement of greenhouse gas (GHG) emissions from paddy soils using the static closed chamber technique. This method is based ...

Lab-Scale Model to Evaluate Odor and Gas Concentrations Emitted by Deep Bedded Pack Manure

A lab-scaled simulated bedded pack model was developed to study air quality and nutrient composition of deep-bedded packs used in cattle mono-slope facilities. This protocol has been used to effectively evaluate many different bedding materials, environmental variables (temperature, humidity), and potential mitigation treatments that can improve air quality in commercial deep-bedded mono-slope facilities. The model is dynamic and allows researchers to easily collect many chemical and physical measurements from the bedded pack. Weekly measurements, collected over the course of six to seven weeks, allows sufficient time to see changes in air quality measurements over time as the bedded pack matures. The data collected from the simulated bedded packs is within the range of concentrations previously measured in commercial deep-bedded mono-slope facilities. Past studies have demonstrated that 8 - 10 experimental units per treatment are sufficient to detect statistical differences among the simulated bedded packs. The bedded packs are easy to maintain, requiring less than 10 minutes of labor per bedded packs per week to add urine, feces, and bedding. Sample collection using the gas sampling system requires 20 - 30 minutes per bedded pack, depending on the measurements that are being collected. The use of lab-scaled bedded packs allows the researcher to control variables such as temperature, humidity, and bedding source that are difficult or impossible to control in a research or commercial facility. While not a perfect simulation of &#34;real-world&#34; conditions, the simulated bedded packs serve as a good model for researchers to use to examine treatment differences among bedded packs. Several lab-scale studies can be conducted to eliminate possible treatments before trying them in a research or commercial-sized facility.

A protocol has been developed to measure gases, odors, and nutrient composition in lab-scaled bedded manure packs, which can be used to study ways to improve air quality in commercial cattle facilities using deep-bedded manure packs.

用实验室尺度模型评价深层包粪排放的恶臭和气体浓度

A lab-scaled simulated bedded pack model was developed to study air quality and nutrient composition of deep-bedded packs used in cattle mono-slope ...

Measurements of CO2 Fluxes at Non-Ideal Eddy Covariance Sites

This protocol is an example of utilizing the eddy covariance (EC) technique to investigate spatially and temporally averaged net CO2 fluxes (net ecosystem production, NEP), in non-typical ecosystems, on a currently reforested windthrow area in Poland. After a tornado event, a relatively narrow &#8220;corridor&#8221; was created within surviving forest stands, which complicates such kind of experiments. The application of other measuring techniques, such as the chamber method, is even more difficult under these circumstances, because especially at the beginning, fallen trees and in general great heterogeneity of the site provide a challenging platform to perform flux measurements and then to properly upscale obtained results. In comparison with standard EC measurements carried out in untouched forests, the case of windthrow areas requires special consideration when it comes to the site location and data analysis in order to ensure their representativeness. Therefore, here we present a protocol of real-time, continuous CO2 flux measurements at a dynamically changing, non-ideal EC site, which includes (1) site location and instrumentation setup, (2) flux computation, (3) rigorous data filtering and quality control, and (4) gap filling and net fluxes partitioning into CO2 respiration and absorption. The main advantage of the described methodology is that it provides a detailed description of the experimental setup and measurement performance from scratch, which can be applied to other spatially limited ecosystems. It can also be viewed as a list of recommendations on how to deal with unconventional site operation, providing a description for non-specialists. Obtained quality-checked, gap filled, half-hour values of net CO2, as well as absorption and respiration fluxes, can be finally aggregated into daily, monthly, seasonal or annual totals.

Measurements of CO2 Fluxes at Non-Ideal Eddy Covariance Sites

The presented protocol uses the eddy covariance method at non-typical locations, applicable to all types of short-canopy ecosystems with limited area, on a currently reforested windthrow site in Poland. Details of measuring site setup rules, flux calculations and quality control, and final result analysis, are described.

非理想涡流位点的 CO2通量测量

This protocol is an example of utilizing the eddy covariance (EC) technique to investigate spatially and temporally averaged net CO2 fluxes (net ecosystem ...

Measurements of Soil Carbon by Neutron-Gamma Analysis in Static and Scanning Modes

The herein described application of the inelastic neutron scattering (INS) method for soil carbon analysis is based on the registration and analysis of gamma rays created when neutrons interact with soil elements. The main parts of the INS system are a pulsed neutron generator, NaI(Tl) gamma detectors, split electronics to separate gamma spectra due to INS and thermo-neutron capture (TNC) processes, and software for gamma spectra acquisition and data processing. This method has several advantages over other methods in that it is a non-destructive in situ method that measures the average carbon content in large soil volumes, is negligibly impacted by local sharp changes in soil carbon, and can be used in stationary or scanning modes. The result of the INS method is the carbon content from a site with a footprint of ~2.5 - 3 m2 in the stationary regime, or the average carbon content of the traversed area in the scanning regime. The measurement range of the current INS system is &#62;1.5 carbon weight % (standard deviation &#177; 0.3 w%) in the upper 10 cm soil layer for a 1 hmeasurement.

Here, we present the protocol for in situ measurement of soil carbon using the neutron-gamma technique for single point measurements (static mode) or field averages (scanning mode). We also describe system construction and elaborate data treatment procedures.

静态和扫描模式下中子伽马分析法测量土壤碳

The herein described application of the inelastic neutron scattering (INS) method for soil carbon analysis is based on the registration and analysis of ...

工程学

Simulating Temperature in a Soil Incubation Experiment

The study of warming impact on soils requires a realistic and accurate representation of temperature. In laboratory incubation studies, a widely adopted method has been to render constant temperatures in multiple chambers, and via comparisons of soil responses between low- and high-temperature chambers, to derive the warming impact on soil changes. However, this commonly used method failed to imitate both the magnitude and amplitude of actual temperatures as observed in field conditions, thus potentially undermining the validity of such studies. With sophisticated environmental chambers becoming increasingly available, it is imperative to examine alternative methods of temperature control for soil incubation research. This protocol will introduce a state-of-the-art environmental chamber and demonstrate both conventional and new methods of temperature control to improve the experimental design of soil incubation. The protocol mainly comprises four steps: temperature monitoring and programming, soil collection, laboratory incubation, and warming effect comparison. One example will be presented to demonstrate different methods of temperature control and the resultant contrasting warming scenarios; that is, a constant temperature design referred to as stepwise warming (SW) and simulated in situ temperature design as gradual warming (GW), as well as their effects on soil respiration, microbial biomass, and extracellular enzyme activities. In addition, we present a strategy to diversify temperature change scenarios to meet specific climate change research needs (e.g., extreme heat). The temperature control protocol and the recommended well-tailored and diversified temperature change scenarios will assist researchers in establishing reliable and realistic soil incubation experiments in the laboratory.

Laboratory soil warming experiments usually employ two or more constant temperatures in multiple chambers. By presenting a sophisticated environmental chamber, we provide an accurate temperature control method to imitate the magnitude and amplitude of in situ soil temperature and improve the experimental design of soil incubation studies.

模拟土壤孵育实验中的温度

The study of warming impact on soils requires a realistic and accurate representation of temperature. In laboratory incubation studies, a widely adopted ...

从农业土壤使用静态钱伯斯温室气体流量测量

摘要

探索更多视频

潜在土壤胞外酶活性的高通量荧光测量

自动系统（绿色饲料）的用于监视肠道的甲烷和二氧化碳从反刍动物排放

一个外线

测量碳为基础的污染物矿化结合使用CO

校准被动采样 - NH多情节场测量

用静止封闭室维持顶空装置对稻田甲烷和一氧化二氮通量的评价

用实验室尺度模型评价深层包粪排放的恶臭和气体浓度

非理想涡流位点的 CO₂通量测量

静态和扫描模式下中子伽马分析法测量土壤碳

模拟土壤孵育实验中的温度