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。

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R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+soil+cover+method+for+field+measurement+of+nitrous+oxide+fluxes.">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/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stochastic+diffusion+model+for+estimating+trace+gas+emissions+with+static+chambers.">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/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comprehensive+approach+to+soil-atmosphere+trace-gas+flux+estimation+with+static+chambers.">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/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regression+models+for+calculating+gas+fluxes+measured+with+a+closed+chamber.">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/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trace+gas+emission+in+chambers.">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., deKlein, C., Harvey, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Data+Analysis+Considerations.+In:+Nitrous+Oxide+Chamber+Methodology+Guidelines.">Data Analysis Considerations. In: Nitrous Oxide Chamber Methodology Guidelines.</a> Ministry for Primary Industries. (6), (2013).</li><li>Grace, P., van der Weerden, T. J., Kelly, K., Rees, R. M., Skiba, U. M., deKlein, C., Harvey, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+Greenhouse+Gas+Measurement+in+the+Field.+In:+Nitrous+Oxide+Chamber+Methodology+Guidelines.">Automated Greenhouse Gas Measurement in the Field. In: Nitrous Oxide Chamber Methodology Guidelines.</a> Ministry for Primary Industries. , (2013).</li><li>Alfaro, M. A., Giltrap, D., Topp, C. F. E., de Klein, C., deKlein, C., Harvey, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+Report+Your+Experimental+Data.+In:+Nitrous+Oxide+Chamber+Methodology+Guidelines.">How to Report Your Experimental Data. In: Nitrous Oxide Chamber Methodology Guidelines.</a> Ministry for Primary Industries. , (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 border="0" cellpadding="0" cellspacing="0" width="941">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">5.9 ml soda glass flat bottom 55 x 15.5 mm</td>
			<td style="width:73px;">Labco Limited</td>
			<td style="width:123px;">719W</td>
			<td style="width:413px;">Collection vials</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">16.5 mm screw caps with pierceable rubber septum</td>
			<td style="width:73px;">Labco Limited</td>
			<td style="width:123px;">VC309</td>
			<td style="width:413px;">Caps for&#160; vials</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">90-well plastic vial rack, 17.1 mm well I.D.</td>
			<td style="width:73px;">Wheaton</td>
			<td style="width:123px;">868810</td>
			<td style="width:413px;">Rack for organizing vials</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Regular bevel needles 23G x 1&#34;</td>
			<td style="width:73px;">BD</td>
			<td style="width:123px;">305193</td>
			<td style="width:413px;">Needles for sample collection</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">Stopcocks with luer connections, 1-way, male slip</td>
			<td style="width:73px;">Cole-Parmer</td>
			<td style="width:123px;">EW-30600-01</td>
			<td style="width:413px;">Stopcocks for syringes</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">30 ml syringe, slip tip</td>
			<td style="width:73px;">BD</td>
			<td style="width:123px;">309651</td>
			<td style="width:413px;">Syringes for sample collection</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Stopwatch or timer</td>
			<td style="width:73px;">Various</td>
			<td style="width:123px;">N/A</td>
			<td style="width:413px;">For timing field sampling</td>
		</tr>
		<tr height="83">
			<td height="83" style="height:83px;width:332px;">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 style="width:73px;">Various</td>
			<td style="width:123px;">N/A</td>
			<td style="width:413px;">Chamber anchor and lid - bottom cut out of anchor, holes for septum and vent tubing bored in lid</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">Gray butyl stoppers 20 mm</td>
			<td style="width:73px;">Wheaton</td>
			<td style="width:123px;">W224100-173</td>
			<td style="width:413px;">Chamber septa for syringe sampling - insert into hole bored in lid top</td>
		</tr>
		<tr height="83">
			<td height="83" style="height:83px;width:332px;">Tygon tubing 4.0 mm I.D. x 5.6 mm O.D.</td>
			<td style="width:73px;">Sigma-Aldrich</td>
			<td style="width:123px;">Z685623</td>
			<td style="width:413px;">Chamber vent tubing - insert in hole bored in lid side, flush with exterior, approximately 25 cm coiled in lid interior (a 1ml syringe tip may be used as an attachement mechanism)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">Adhesive foam rubber tape or HDPE O-ring</td>
			<td style="width:73px;">Various</td>
			<td style="width:123px;">N/A</td>
			<td style="width:413px;">Chamber sealing mechanism - fastened to underside of lid rim</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">Reflective&#160; insulation, 0.3125&#34; thickness</td>
			<td style="width:73px;">Lowe&#39;s</td>
			<td style="width:123px;">409818</td>
			<td style="width:413px;">Insulating and reflective coating - affix to exterior of chamber lid</td>
		</tr>
		<tr height="62">
			<td height="62" style="height:62px;width:332px;">Large metal binder clips, 2&#34; size with 1&#34; capacity, or manufactured draw latch as appropriate</td>
			<td style="width:73px;">Staples / McMaster</td>
			<td style="width:123px;">831610 (Staples) / 1863A21 (McMaster)</td>
			<td style="width:413px;">Lid attachment mechanism - for clamping lid to anchor during sampling</td>
		</tr>
		<tr height="104">
			<td height="104" style="height:104px;width:332px;">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 style="width:73px;">Various</td>
			<td style="width:123px;">N/A</td>
			<td style="width:413px;">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 ...

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41.0K 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

Surface Renewal: An Advanced Micrometeorological Method for Measuring and Processing Field-Scale Energy Flux Density Data

Advanced micrometeorological methods have become increasingly important in soil, crop, and environmental sciences. For many scientists without formal training in atmospheric science, these techniques are relatively inaccessible. Surface renewal and other flux measurement methods require an understanding of boundary layer meteorology and extensive training in instrumentation and multiple data management programs. To improve accessibility of these techniques, we describe the underlying theory of surface renewal measurements, demonstrate how to set up a field station for surface renewal with eddy covariance calibration, and utilize our open-source turnkey data logger program to perform flux data acquisition and processing. The new turnkey program returns to the user a simple data table with the corrected fluxes and quality control parameters, and eliminates the need for researchers to shuttle between multiple processing programs to obtain the final flux data. An example of data generated from these measurements demonstrates how crop water use is measured with this technique. The output information is useful to growers for making irrigation decisions in a variety of agricultural ecosystems. These stations are currently deployed in numerous field experiments by researchers in our group and the California Department of Water Resources in the following crops: rice, wine and raisin grape vineyards, alfalfa, almond, walnut, peach, lemon, avocado, and corn.

Surface renewal is a micrometeorological method that is being used increasingly to determine energy fluxes, but its technical complexity makes it inaccessible to a broad audience. We describe the steps needed to set up and calibrate a surface renewal field station, to acquire and process data, and to correctly interpret results.

表面重建:一种先进的微气象法测量和处理油田规模能流密度数据

Advanced micrometeorological methods have become  increasingly important in soil, crop, and environmental sciences.  For many scientists without formal ...

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环境科学

Colorimetric Paper-based Detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from Large Volumes of Agricultural Water

This protocol describes rapid colorimetric detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from large volumes (10 L) of agricultural waters. Here, water is filtered through sterile Modified Moore Swabs (MMS), which consist&#160;of a simple gauze filter enclosed in a plastic cartridge, to concentrate bacteria. Following filtration, non-selective or selective enrichments for the target bacteria are performed in the MMS. For colorimetric detection of the target bacteria, the enrichments are then assayed using paper-based analytical devices (&#181;PADs) embedded with bacteria-indicative substrates. Each substrate reacts with target-indicative bacterial enzymes, generating colored products that can be detected visually (qualitative detection) on the &#181;PAD. Alternatively, digital images of the reacted &#181;PADs can be generated with common scanning or photographic devices and analyzed using ImageJ software, allowing for more objective and standardized interpretation of results. Although the biochemical screening procedures are designed to identify the aforementioned bacterial pathogens, in some cases enzymes produced by background microbiota or the degradation of the colorimetric substrates may produce a false positive. Therefore, confirmation using a more discriminatory diagnostic is needed. Nonetheless, this bacterial concentration and detection platform is inexpensive, sensitive (0.1 CFU/ml detection limit), easy to perform, and rapid (concentration, enrichment, and detection are performed within approximately 24&#160;hr), justifying its use as an initial screening method for the microbiological quality of agricultural water.

Colorimetric Paper-based Detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from Large Volumes of Agricultural Water

A protocol involving integrated concentration, enrichment, and end-point colorimetric detection of foodborne pathogens in large volumes of agricultural water is presented here. Water is filtered through Modified Moore Swabs (MMS), enriched with selective or non-selective media, and detection is performed using paper-based analytical devices (&#181;PAD) imbedded with bacterial-indicative colorimetric substrates.

比色纸为基础的检测<em&gt;大肠杆菌</em&gt;<em&gt;沙门氏菌</em&gt;属，和<em&gt;单核细胞增生李斯特氏菌</em&gt;从农业用水大容量

This protocol describes rapid colorimetric detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from large volumes (10 L) of ...

Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) loading from lake sediments can account for a substantial portion of the total P load in eutrophic, and some mesotrophic, lakes. Laboratory determination of P release rates from sediment cores is one approach for determining the role of internal P loading and guiding management decisions. Two principal alternatives to experimental determination of sediment P release exist for estimating internal load: in situ measurements of changes in hypolimnetic P over time and P mass balance. The experimental approach using laboratory-based sediment incubations to quantify internal P load is a direct method, making it a valuable tool for lake management and restoration.
Laboratory incubations of sediment cores can help determine the relative importance of internal vs. external P loads, as well as be used to answer a variety of lake management and research questions. We illustrate the use of sediment core incubations to assess the effectiveness of an aluminum sulfate (alum) treatment for reducing sediment P release. Other research questions that can be investigated using this approach include the effects of sediment resuspension and bioturbation on P release.
The approach also has limitations. Assumptions must be made with respect to: extrapolating results from sediment cores to the entire lake; deciding over what time periods to measure nutrient release; and addressing possible core tube artifacts. A comprehensive dissolved oxygen monitoring strategy to assess temporal and spatial redox status in the lake provides greater confidence in annual P loads estimated from sediment core incubations.

Lake eutrophication is a water quality issue worldwide, making the need to identify and control nutrient sources critical. Laboratory determination of phosphorus release rates from sediment cores is a valuable approach for determining the role of internal phosphorus loading and guiding management decisions.

实验室确定的磷通量湖泊沉积物作为内部磷载入一个测量

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) ...

Measurement of H2S in Crude Oil and Crude Oil Headspace Using Multidimensional Gas Chromatography, Deans Switching and Sulfur-selective Detection

A method for the analysis of dissolved hydrogen sulfide in crude oil samples is demonstrated using gas chromatography. In order to effectively eliminate interferences, a two dimensional column configuration is used, with a Deans switch employed to transfer hydrogen sulfide from the first to the second column (heart-cutting). Liquid crude samples are first separated on a dimethylpolysiloxane column, and light gases are heart-cut and further separated on a bonded porous layer open tubular (PLOT) column that is able to separate hydrogen sulfide from other light sulfur species. Hydrogen sulfide is then detected with a sulfur chemiluminescence detector, adding an additional layer of selectivity. Following separation and detection of hydrogen sulfide, the system is backflushed to remove the high-boiling hydrocarbons present in the crude samples and to preserve chromatographic integrity. Dissolved hydrogen sulfide has been quantified in liquid samples from 1.1 to 500 ppm, demonstrating wide applicability to a range of samples. The method has also been successfully applied for the analysis of gas samples from crude oil headspace and process gas bags, with measurement from 0.7 to 9,700 ppm hydrogen sulfide.

Measurement of H2S in Crude Oil and Crude Oil Headspace Using Multidimensional Gas Chromatography, Deans Switching and Sulfur-selective Detection

A multidimensional gas chromatography method for the analysis of dissolved hydrogen sulfide in liquid crude oil samples is presented. A Deans switch is used to heart-cut light sulfur gases for separation on a secondary column and detection on a sulfur chemiluminescence detector.

h的测量<sub&gt; 2</sub&gt; S在原油和原油顶空用多维气相色谱法，院长交换和选择性硫检测

A method for the analysis of dissolved hydrogen sulfide in crude oil samples is demonstrated using gas chromatography. In order to effectively eliminate ...

Enhancement of the Initial Growth Rate of Agricultural Plants by Using Static Magnetic Fields

Electronic devices and high-voltage wires induce magnetic fields. A magnetic field of 1,300-2,500 Gauss (0.2 Tesla) was applied to Petri dishes containing seeds of Garden Balsam (Impatiens balsamina), Mizuna (Brassica rapa var. japonica), Komatsuna (Brassica rapa var. perviridis), and Mescluns (Lepidium sativum). We applied magnets under the culture dish. During the 4 days of application, we observed that the stem and root length increased. The group subjected to magnetic field treatment (n = 10) showed a 1.4 times faster rate of growth compared with the control group (n = 11) in a total of 8 days (p &#60;0.0005). This rate is 20% higher than that reported in previous studies. The tubulin complex lines did not have connecting points, but connecting points occur upon the application of magnets. This shows complete difference from the control, which means abnormal arrangements. However, the exact cause remains unclear. These results of growth enhancement of applying magnets suggest that it is possible to enhance the growth rate, increase productivity, or control the speed of germination of plants by applying static magnetic fields. Also, magnetic fields can cause physiological changes in plant cells and can induce growth. Therefore, stimulation with a magnetic field can have possible effects that are similar to those of chemical fertilizers, which means that the use of fertilizers can be avoided.

The goal of this protocol is to demonstrate the acceleration of the initial growth rate of plants by applying static magnetic fields with no external energy.

采用静态磁场农业植物初始增长率提高

Electronic devices and high-voltage wires induce magnetic fields. A magnetic field of 1,300-2,500 Gauss (0.2 Tesla) was applied to Petri dishes containing ...

Capturing Flow-weighted Water and Suspended Particulates from Agricultural Canals During Drainage Events

The purpose of this study is to describe the methods used to capture flow-weighted water and suspended particulates from farm canals during drainage discharge events. Farm canals can be enriched by nutrients such as phosphorus (P) that are susceptible to transport. Phosphorus in the form of suspended particulates can significantly contribute to the overall P loads in drainage water. A settling tank experiment was conducted to capture suspended particulates during discrete drainage events. Farm canal discharge water was collected in a series of two 200 L settling tanks over the entire duration of the drainage event, so as to represent a composite subsample of the water being discharged. Imhoff settling cones are ultimately used to settle out the suspended particulates. This is achieved by siphoning water from the settling tanks via the cones. The particulates are then collected for physico-chemical analyses.

Nutrients present in particulate form can contribute significantly to the overall loads in agricultural drainage waters. This study describes a novel method to capture flow-weighted water and suspended particulates from farm canal drainage over the entire duration of the drainage event.

在排水过程中捕获农用运河中的流动加权水和悬浮颗粒

The purpose of this study is to describe the methods used to capture flow-weighted water and suspended particulates from farm canals during drainage ...

Methodology for Developing Life Tables for Sessile Insects in the Field Using the Whitefly, Bemisia tabaci, in Cotton As a Model System

Life tables provide a means of measuring the schedules of birth and death from populations over time. They also can be used to quantify the sources and rates of mortality in populations, which has a variety of applications in ecology, including agricultural ecosystems. Horizontal, or cohort-based, life tables provide for the most direct and accurate method of quantifying vital population rates because they follow a group of individuals in a population from birth to death. Here, protocols are presented for conducting and analyzing cohort-based life tables in the field that takes advantage of the sessile nature of the immature life stages of a global insect pest, Bemisia tabaci. Individual insects are located on the underside of cotton leaves and are marked by drawing a small circle around the insect with a non-toxic pen. This insect can then be observed repeatedly over time with the aid of hand lenses to measure development from one stage to the next and to identify stage-specific causes of death associated with natural and introduced mortality forces. Analyses explain how to correctly measure multiple mortality forces that act contemporaneously within each stage and how to use such data to provide meaningful population dynamic metrics. The method does not directly account for adult survival and reproduction, which limits inference to dynamics of immature stages. An example is presented that focused on measuring the impact of bottom-up (plant quality) and top-down (natural enemies) effects on the mortality dynamics of B. tabaci in the cotton system.

Methodology for Developing Life Tables for Sessile Insects in the Field Using the Whitefly, Bemisia tabaci, in Cotton As a Model System

Life tables allow quantification of the sources and rates of mortality in insect populations and contribute to understanding, predicting and manipulating population dynamics in agroecosystems. Methods for conducting and analyzing cohort-based life tables in the field for an insect with sessile immature life stages are presented.

用虱、烟粉虱在棉花中开发无梗昆虫生命表的方法作为模型系统

Life tables provide a means of measuring the schedules of birth and death from populations over time. They also can be used to quantify the sources and ...

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 ...

Experimental Study of the Relationship Between Particle Size and Methane Sorption Capacity in Shale

The amount of adsorbed shale gas is a key parameter used in shale gas resource evaluation and target area selection, and it is also an important standard for evaluating the mining value of shale gas. Currently, studies on the correlation between particle size and methane adsorption are controversial. In this study, an isothermal adsorption apparatus, the gravimetric sorption analyzer, is used to test the adsorption capacity of different particle sizes in shale to determine the relationship between the particle size and the adsorption capacity of shale. Thegravimetric method requires fewer parameters and produces better results in terms of accuracy and consistency than methods like the volumetric method. Gravimetric measurements are performed in four steps: a blank measurement, preprocessing, a buoyancy measurement, and adsorption and desorption measurements. Gravimetric measurement is presently considered to be a more scientific and accurate method of measuring the amount of adsorption; however, it is time-consuming and requires a strict measuring technique. A Magnetic Suspension Balance (MSB) is the key to verify the accuracy and consistency of this method. Our results show that adsorption capacity and particle size are correlated, but not a linear correlation, and the adsorptions in particles sieved into 40 - 60 and 60 - 80 meshes tend to be larger. We propose that the maximum adsorption corresponding to the particle size is approximately 250 &#181;m (60 mesh) in the shale gas fracturing.

We use an isothermal adsorption apparatus, the gravimetric sorption analyzer, to test the adsorption capacity of different particle sizes of shale, in order to find out the relationship between particle size and the adsorption capacity of shale.

页岩中粒径与甲烷吸附能力关系的实验研究

The amount of adsorbed shale gas is a key parameter used in shale gas resource evaluation and target area selection, and it is also an important standard ...

Detection of Viruses from Bioaerosols Using Anion Exchange Resin

This protocol demonstrates a customized bioaerosol sampling method for viruses. In this system, anion exchange resin is coupled with liquid impingement-based air sampling devices for efficacious concentration of negatively-charged viruses from bioaerosols. Thus, the resin serves as an additional concentration step in the bioaerosol sampling workflow. Nucleic acid extraction of the viral particles is then performed directly from the anion exchange resin, with the resulting sample suitable for molecular analyses. Further, this protocol describes a custom-built bioaerosol chamber capable of generating virus-laden bioaerosols under a variety of environmental conditions and allowing for continuous monitoring of environmental variables such as temperature, humidity, wind speed, and aerosol mass concentration. The main advantage of using this protocol is increased sensitivity of viral detection, as assessed via direct comparison to an unmodified conventional liquid impinger. Other advantages include the potential to concentrate diverse negatively-charged viruses, the low cost of anion exchange resin (~$0.14 per sample), and ease of use. Disadvantages include the inability of this protocol to assess infectivity of resin-adsorbed viral particles, and potentially the need for the optimization of the liquid sampling buffer used within the impinger.

An anion exchange resin-based method, adapted to liquid impingement-based bioaerosol sampling of viruses is demonstrated. When coupled with downstream molecular detection, the method allows for facile and sensitive detection of viruses from bioaerosols.