We thank Anne Gibson, Katherine Jones, Chris Kolodziejczyk, Alicia Naranjo, Kyle Tiner, and numerous students and temporary technicians for operating the LYCOG facility, conducting sampling, and data processing. L.G.R. acknowledges USDA-NIFA (2010-65615-20632).

1.收集土壤石柱用作称重测渗计<ol><li> 1.5米，深8毫米厚的钢构建开放式钢箱1×1米的正方形。 </li><li>按开放式盒垂直插入土中，用液压机安装在螺旋锚钻3米深入到土壤中。 </li><li>挖掘使用反铲挖土机或类似设备的包裹整体。 </li><li>放置在与土壤接触的玻璃纤维燃烧芯的整体件的基座。穿过钢基灯芯入10升的储排空整料，然后焊接钢底座上的框的底部。 </li><li>通过施加一个非残留除草剂，如草甘膦杀死在整料现有植被。 </li></ol> 2.建立土壤石柱植物群落<ol><li>植物与每个七种高杆草八苗的巨石野草，杂类草，为每平方米56工厂总密度。 <ol><li&gt;植物下面的草:Bouteloua curtipendula（侧燕麦GRAMA）， 裂稃棒 （小白羊），Sorghastrum垂穗（Indiangrass），Tridens albescens（白tridens）。 </li><li>植物以下福布斯: 丹参Residhotel Azurea酒店 （投手圣人）， 加拿大一枝黄花 （加拿大一枝黄花）， 合欢草属illinoensis（伊利诺伊bundleflower，豆类）。 </li></ol></li><li>在拉丁方设计植物幼苗，再随机为每个巨石。 </li><li>水下面种植移植约2个月。我们的目标是初步建立过程中尽量减少水分胁迫。使用任何方便的方法，如手杖或花园喷水器。浇水的频率取决于当地天气和气候，环境降雨的特别的发生。 </li><li>在最初的移植建立阶段，维持在环境降雨的移植，只要有必要的，而室（科3）构成。卸下建立由手工除草过程中出现的巨石有害物种。 </li></ol> 3.室内设计<ol><li>构建两院各宽1.2米，1.5米高，长60米，分为十个5米长的部分。从尺寸5米×1.2米×1.6米深，埋到1.5米重钢建设部分。 <ol><li>在每个部分中安装四个巨石，每两个土壤类型，随机二阶巨石。安装每个巨石顶上4540千克能力的平衡。 </li><li>包括Bastsil巨石在偶数段的配对。 </li></ol></li><li>加入地上部分用1米长×1米宽×0.3米高钣金导管，以提供一个途径气流相邻部分。 <ol><li>供应冷却剂在10℃下从161.4千瓦致冷单元到每个管道内的冷却盘管。 </li><li>附上清晰的棚膜，如其他使用的植物（厚度0.006"/ 15mm）的，气候操控实验23。 </li><li>适合每盖一个拉链开口由瓣草案的支持，以允许访问的巨石进行采样。 </li><li>取下塑料盖在生长季节的结束。 </li></ol></li></ol> 4， 二氧化碳和空气温度测量;温度控制<ol><li>两个样品室的入口和出口C A通过位于在superambient和低于环境室的入口和出口过滤空气样品线每2分钟。这些数据告诉二氧化碳注入和风扇转速控制。 <ol><li>样品C A和水汽含量，并在每个5米段在20分钟的间隔的入口和出口测量空气温度（T A）中。 </li><li>测量根据制造商的协议，使用红外气体分析仪的所有空气样本二氧化碳和水蒸汽的含量是实时的。 </li><li>测量T A在入口，中点，一个每个部分具有屏蔽细导线热电偶D出口。 </li></ol></li><li>调节冷却剂通过冷却盘管在每节，以保持从部分一致的平均值（中间部分）T A到接近室温T A部的入口的流动。 </li><li>定位量子传感器具有的天空一览无遗，并根据制造商的协议测量光量子通量密度。光平是输入鼓风机控制算法。 </li></ol> 5. C A处理中的应用<ol><li>白天<ol><li>混合纯的二氧化碳（CO 2）与进入的环境空气，以500μl的L-1 C A，在superambient腿的入口导管使用质量流量控制器。见第4 C A测量细节。 </li><li>通过使用风机入口处的第1室和下游段的平流输送富氧空气。 </li><li>中号通过调节风机转速aintain的390微升L-1（环境空气）所需的出口C A。 <ol><li>增加风机转速，如果出口C A低于设定值。这允许对CO 2的植物吸收较少的时间，从而获得更高的C出口甲 。 </li><li>降低鼓风机转速，如果C出口A是高于设定点。 </li></ol></li><li>使用在低于室温室同样的方法，除了将环境空气和控制，以实现250微升L-1出口C A。 </li></ol></li><li>夜间<ol><li>反向空气流的方向。 </li><li>注入二氧化碳进入superambient室的日间出口端达到530微升L-C A和控制平流率保持640微升L-1在夜间出口（白天入口。 </li><li>将环境空气在〜390微升L-1 的 CO 2进入夜间入口子环境室及控制平流率（白天出口）维持530微升L-1在夜间退出。 </li></ol></li></ol> 6.降水输入<ol><li>应用平均生长季节降雨量为每个整体。 <ol><li>从通过滴灌系统国产水源供水给每个整体。安排灌溉事件及其用量近似的实验场所季节性降雨模式。确切的时间表取决于当地的气候。 </li></ol></li><li>控制应用时机与数据记录器和测量应用卷流量计。 </li></ol> 7取样<ol><li>在二氧化碳控制期间测量体积土壤含水量（VSWC）每周的垂直剖面，用中子衰减仪或其他合适的探头。 <ol><li>推荐配置文件的增量为20厘米深度的增量1米德第p，和1个50厘米增量低于1微米。 </li></ol></li><li>衡量整体地上净初级生产力（ANPP）通过收集所有站在地上生物量在生长季节的结束。 <ol><li>所有地上生物量每年除去，因此现存生物表示当前的主生产。 </li><li>排序按品种，干燥至恒重采样量，并权衡。 </li><li>使用个别品种的生物质来量化植物物种ANPP的贡献。 </li></ol></li></ol>

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The authors have nothing to disclose.

该LYCOG设施达到保持C A浓度对三种土壤类型建立实验草地群落250〜500微升L-1连续梯度其业务目标。 C中的一个变化是线性的规定范围。每个部分内的空气温度升高，却被段之间的冷却盘管在大部分路段复位。其结果是，保持一致的平均温度从段到段的操作目标是满足以上多数渐变。温度和C 控制在春季和初夏期间容易维护，当土壤含水量较高，植物处于最高的光合?...

大气中的二氧化碳浓度（C A）最近增加了近400微升L -1约270微升L-1之前的工业革命。 C A预计2100年1至少要达到550微升L-1。增加这个比率超过观察，在过去50万年的任何C A的变化。改变C A的前所未有的速度提出了生态系统的非线性或阈值响应增加C A的可能性。大多数生态系统规模的C A浓缩试验只适用两种处理中，丰富了C A和控制单级。这些实验已经极大地扩展了我们的C 的丰富的生态系统影响的认识。然而，这可以揭示非线性的生态系统的响应的存在，以增加C A的替代方法是，跨到一个连续范围低于环境的生态系统的研究superambient C A。低于环境C A是很难在现场维护，并且最经常被使用生长室2研究。 Superambient C A一直用生长箱，开顶式气室，并提供免费空气富集技术3，4研究。 C A富集操作通过含有多种土壤类型的景观。土属性可以强烈地影响生态系统的反应，C A富集。例如，土壤质地确定的水和养分的土壤剖面5的保留，其可用性植物6，和有机物7-9的数量和质量。土壤水分的有效性是生态系统的反应时在水中有限的系统，包括最草原10 A富集的关键调解人。近场C A浓缩试验通常都检查只有一种土壤类型，以及控制不断诉测试arying C A富集在几个土壤类型所缺乏的。如果C A丰富的生态系统过程的影响具有不同土壤类型，有足够的理由期待空间变化的生态系统响应C A富集和气候11,12随之而来的变化。 的蒸渗仪二氧化碳梯度（LYCOG）设施的目的是要解决的空间变化的生态系统中的至C A水平范围从〜250到500微升L -1的非线性和阈值响应的问题。 LYCOG创建C A对多年生草地植物群落上代表广泛的质地，N和C的含量，以及水文美国中原南部的部分草原的性质土壤中生长的规定的梯度。在设施中使用的特定的土壤系列是休斯敦黑粘土（32巨石），一个变性土（城投Haplustert）典型的低地;奥斯汀（32巨石），高碳氮内特，粉质粘土软土（Udorthentic Haplustol）典型的高地;和Bastsil（16巨石），冲积砂壤土淋溶土（城投Paleustalf）。 在LYCOG采用的工作原理是利用植物的光合能力耗尽C A从包裹空气的定向移动通过封闭室。治疗目标是保持在C A的恒定线性白天梯度从500到250微升L-1。要做到这一点，LYCOG由两个线性腔室，一个腔室superambient保持梯度从500至390（环境）的部分微升L-1 C A，和低于环境室保持的390到250微升L-1部梯度。这两个腔室并排放置，面向上的南北轴。当植物光合能力是足够的一年中部分中的C A梯度维持;通常四月下旬至十一月初。 该室含有调节C A梯度，控制空气温度（T A）接近环境值，并应用统一的降水量所有的土壤需要的传感器和仪器。土壤是从安装在仪表以确定水预算的所有组分水文隔离称量渗漏池附近黑土大草原收集完好整料。水的量和时间，即近似的降雨事件的季节性和期间的平均年降水量达事件的应用。因此，LYCOG能够评估低于环境来superambient C A和土壤类型对草地生态系统功能的长期影响，包括水和碳预算。 LYCOG是第三代的美国农业部ARS草地水土保持研究实验室进行的C A梯度实验。第一代是一个雏形低于环境来所建立的梯度法13的活力和提高了我们的植物叶级生理反应的认识，以低于室温的C A 14-20变化的环境梯度。第二代是概念的油田规模的应用程序，以常年的 C 4草原，与延伸至200〜550μLL -1 21梯度。该油田规模试验首次提供了证据表明，用C草地生产力增加了浓缩可能饱和电流环境浓度20附近，部分原因是因为氮的可用性可能会限制植物生产力superambient C A 22。 LYCOG扩展了第二代实验通过将不同的纹理，让强大的测试在C草地群落的响应土壤的互动效应的复制的土壤。

<table>
	<tbody>
		<tr>
			<td>Dataloggers, multiplexers</td>
			<td>Campell Scientific, Logan, UT, USA</td>
			<td>CR-7, CR-10, CR-21X, SDM-A04, SDM-CD16AC, AM25T</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermocouples: Copper-constantan</td>
			<td>Omega Engineering, Inc., Stamford, CT, USA</td>
			<td>TT-T-40-SLE, TT-T-24-SLE</td>
			<td></td>
		</tr>
		<tr>
			<td>Quantum sensor</td>
			<td>Li-Cor Biosciences, Lincoln, NE, USA</td>
			<td>LI-190SB</td>
			<td></td>
		</tr>
		<tr>
			<td>CO2/H2O analyzer</td>
			<td>Li-Cor Biosciences, Lincoln, NE, USA</td>
			<td>LI-7000</td>
			<td></td>
		</tr>
		<tr>
			<td>Lysimeter scales</td>
			<td>Avery Weigh-Tronix, Houston, TX, USA</td>
			<td>DSL-3636-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Air sampling pump</td>
			<td>Grace Air Components, Houston, TX, USA</td>
			<td>VP 0660</td>
			<td></td>
		</tr>
		<tr>
			<td>Dew-point generator</td>
			<td>Li-Cor Biosciences, Lincoln, NE, USA</td>
			<td>LI-610</td>
			<td></td>
		</tr>
		<tr>
			<td>Cold water chiller</td>
			<td>AEC Application Engineering, Wood Dale, IL, USA</td>
			<td>CCOA-50</td>
			<td></td>
		</tr>
		<tr>
			<td>Chilled water flow control values</td>
			<td>Belimo Air Controls, Danbury, CT, USA</td>
			<td>LRB24-SR</td>
			<td></td>
		</tr>
		<tr>
			<td>Chilled-water cooling coils</td>
			<td>Coil Company, Paoli, PA, USA</td>
			<td>WC12-C14-329-SCA-R</td>
			<td></td>
		</tr>
		<tr>
			<td>Carbon dioxide refrigerated liquid</td>
			<td>Temple Welding Supply, Temple, TX, USA</td>
			<td>UN2187</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyethylene film</td>
			<td>AT Plastics, Toronto, ON, Canada</td>
			<td>Dura-film Super Dura 4</td>
			<td></td>
		</tr>
		<tr>
			<td>Blower motor/controller</td>
			<td>Dayton Electric, Lake Forest, IL, USA</td>
			<td>2M168C/4Z829</td>
			<td></td>
		</tr>
		<tr>
			<td>Solenoids</td>
			<td>Industrial Automation, Cornelius, NC, USA</td>
			<td>U8256B046V-12/DC</td>
			<td></td>
		</tr>
		<tr>
			<td>Leachate collection pump</td>
			<td>Gast Manufacturing, Benton Harbor, MI, USA</td>
			<td>0523-V191Q-G588DX</td>
			<td></td>
		</tr>
	</tbody>
</table>

a co2 concentration gradient facility for testing co2 enrichment and soil effects on grassland ecosystem function

继续增加大气中二氧化碳的浓度（C a）任务技术研究对陆地生态系统的影响。大多数实验检查只有两个或C 的浓度和单个土壤类型的几级，但如果C A可改变为从低于环境的梯度superambient多个土壤浓度，就可以辨别过去的生态系统的响应是否可以继续直线在未来，无论是应对可能会在景观各不相同。在蒸渗仪二氧化碳梯度基金申请250至500微升L-C A梯度含有粘土，粉质粘土和沙土渗漏池建立黑土草原植物群落。该梯度为光合作用植被温控室封闭在创建逐步消耗的二氧化碳从空气通过室流出定向。保持适当的空气流率，足够photosynthetic能力，温度控制是至关重要的克服系统的主要局限，这是下降的夏季光合速率和增加水的压力。该设施是一种经济的替代的C A富集的其他技术，成功地洞察生态系统响应的形状，以低于环境到superambient C A富集，并且可以适于对测试为二氧化碳与其他温室气体，例如甲烷或臭氧相互作用。

渐变的superambient和低于环境部分被保持在单独的腔室（ 图1）。但是，超过七年操作（2007 - 2013年）的，所述腔保持在C中的线性梯度的浓度为500〜250微升L-1（图2）与只有一小的不连续性在C A的富集腔室的出口之间（整体式40）和梯度的低于环境部的入口（巨石41）。 气温和水汽压赤字依然从部分同时在superambient和低于环境室部...

Watch this Scientific Journal Video about A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function at JoVE.com

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

在蒸渗仪二氧化碳梯度设备创建了一个250到500μLL -1线性二氧化碳梯度对粘土，粉质粘土和沙土巨石温控室的住房草地植物群落。该设施被用来确定过去和未来的二氧化碳水平如何影响草地碳循环。

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 ...

a-co2-concentration-gradient-facility-for-testing-co2-enrichment-soil

Research

JoVE Journal

Environment

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

11.4K 次观看.  Grassland Soil and Water Research Laboratory. 在蒸渗仪二氧化碳梯度设备创建了一个250到500μLL -1线性二氧化碳梯度对粘土，粉质粘土和沙土巨石温控室的住房草地植物群落。该设施被用来确定过去和未来的二氧化碳水平如何影响草地碳循环。 

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

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes and soil organic matter formation to small-scale stable-isotope biomarker probing. Coupling multiple stable isotopes such as 13C with 15N, 18O or&#160;2H has the potential to reveal even more information about complex stoichiometric relationships during biogeochemical transformations. Isotope labeled plant material has been used in various studies of litter decomposition and soil organic matter formation1-4. From these and other studies, however, it has become apparent that structural components of plant material behave differently than metabolic components (i.e. leachable low molecular weight compounds) in terms of microbial utilization and long-term carbon storage5-7. The ability to study structural and metabolic components separately provides a powerful new tool for advancing the forefront of ecosystem biogeochemical studies. Here we describe a method for producing 13C and 15N labeled plant material that is either uniformly labeled throughout the plant or differentially labeled in structural and metabolic plant components.
Here, we present the construction and operation of a continuous 13C and 15N labeling chamber that can be modified to meet various research needs. Uniformly labeled plant material is produced by continuous labeling from seedling to harvest, while differential labeling is achieved by removing the growing plants from the chamber weeks prior to harvest. Representative results from growing Andropogon gerardii Kaw demonstrate the system&#39;s ability to efficiently label plant material at the targeted levels. Through this method we have produced plant material with a 4.4 atom%13C and 6.7 atom%15N uniform plant label, or material that is differentially labeled by up to 1.29 atom%13C and 0.56 atom%15N in its metabolic and structural components (hot water extractable and hot water residual components, respectively). Challenges lie in maintaining proper temperature, humidity, CO2 concentration,&#160;and light levels in an airtight 13C-CO2 atmosphere for successful plant production. This chamber description represents a useful research tool to effectively produce uniformly or differentially multi-isotope labeled plant material for use in experiments on ecosystem biogeochemical cycling.

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

This method explains how to build and operate a continuous 13C and 15N isotope labeling chamber for uniform or differential plant tissue labeling. Representative results from metabolic and structural labeling of Andropogon gerardii are discussed.

设计一个连续和操作<sup&gt; 13</sup&gt; C和<sup&gt; 15</sup&gt;Ñ贴标商会统一或差分，代谢和结构，植物同位素标记

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes ...

科研

环境科学

Design and Construction of an Urban Runoff Research Facility

As the urban population increases, so does the area of irrigated urban landscape. Summer water use in urban areas can be 2-3x winter base line water use due to increased demand for landscape irrigation. Improper irrigation practices and large rainfall events can result in runoff from urban landscapes which has potential to carry nutrients and sediments into local streams and lakes where they may contribute to eutrophication. A 1,000 m2 facility was constructed which consists of 24 individual 33.6 m2 field plots, each equipped for measuring total runoff volumes with time and collection of runoff subsamples at selected intervals for quantification of chemical constituents in the runoff water from simulated urban landscapes. Runoff volumes from the first and second trials had coefficient of variability (CV) values of 38.2 and 28.7%, respectively. CV values for runoff pH, EC, and Na concentration for both trials were all under 10%. Concentrations of DOC, TDN, DON, PO4-P, K+, Mg2+, and Ca2+ had CV values less than 50% in both trials. Overall, the results of testing performed after sod installation at the facility indicated good uniformity between plots for runoff volumes and chemical constituents. The large plot size is sufficient to include much of the natural variability and therefore provides better simulation of urban landscape ecosystems.

This paper describes the design, construction, and function of a 1,000 m2 facility containing 24 individual 33.6 m2 field plots equipped for measuring total runoff volumes with time and collection of runoff subsamples at selected intervals for quantification of chemical constituents in the runoff water from simulated home lawns.

设计一个城市径流研究设施的建设

As the urban population increases, so does the area of irrigated urban landscape. Summer water use in urban areas can be 2-3x winter base line water use ...

An Optimized Enrichment Technique for the Isolation of Arthrobacter Bacteriophage Species from Soil Sample Isolates

Bacteriophage isolation from environmental samples has been performed for decades using principles set forth by pioneers in microbiology. The isolation of phages infecting Arthrobacter hosts has been limited, perhaps due to the low success rate of many previous isolation techniques, resulting in an underrepresented group of Arthrobacter phages available for study. The enrichment technique described here, unlike many others, uses a filtered extract free of contaminating bacteria as the base for indicator bacteria growth, Arthrobactersp. KY3901, specifically. By first removing soil bacteria the target phages are not hindered by competition with native soil bacteria present in initial soil samples. This enrichment method has resulted in dozens of unique phages from several different soil types and even produced different types of phages from the same enriched soil sample isolate. The use of this procedure can be expanded to most nutrient rich aerobic media for the isolation of phages in a vast diversity of interesting host bacteria.

An Optimized Enrichment Technique for the Isolation of Arthrobacter Bacteriophage Species from Soil Sample Isolates

We present an enrichment protocol for the isolation of bacteriophages infecting bacteria in the Arthrobacter genus. This enrichment protocol produces fast and reproducible results for the isolation and amplification of Arthrobacter phages from soil isolates.

一种优化富集技术的隔离<em&gt;节杆菌</em&gt;噬菌体种从土壤样品隔离

Bacteriophage isolation from environmental samples has been performed for decades using principles set forth by pioneers in microbiology. The isolation of ...

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 ...

A Protocol for Collecting and Constructing Soil Core Lysimeters

Leaching of nutrients from land applied fertilizers and manure used in agriculture can lead to accelerated eutrophication of surface water. Because the landscape has complex and varied soil morphology, an accompanying disparity in flow paths for leachate through the soil macropore and matrix structure is present. The rate of flow through these paths is further affected by antecedent soil moisture. Lysimeters are used to quantify flow rate, volume of water and concentration of nutrients leaching downward through soils. While many lysimeter designs exist, accurately determining the volume of water and mass balance of nutrients is best accomplished with bounded lysimeters that leave the natural soil structure intact. 
Here we present a detailed method for the extraction and construction of soil core lysimeters equipped with soil moisture sensors at 5 cm and 25 cm depths. Lysimeters from four different Coastal Plain soils (Bojac, Evesboro, Quindocqua and Sassafras) were collected on the Delmarva Peninsula and moved to an indoor climate controlled facility. Soils were irrigated once weekly with the equivalent of 2 cm of rainfall to draw down soil nitrate-N concentrations. At the end of the draw down period, poultry litter was applied (162 kg TN ha-1) and leaching was resumed for an additional five weeks. Total recovery of applied irrigation water varied from 71% to 85%. Nitrate-N concentration varied over the course of the study from an average of 27.1 mg L-1 before litter application to 40.3 mg L-1 following litter application. While greatest flux of nutrients was measured in soils dominated by coarse sand (Sassafras) the greatest immediate flux occurred from the finest textured soil with pronounced macropore development (Quindocqua).

A detailed method for extraction and assembly of intact soil core lysimeters and their use for study of leachate and associated loss of nutrients from surface applied poultry litter is demonstrated.

一种用于收集和构建土芯协议测渗计

Leaching of nutrients from land applied fertilizers and manure used in agriculture can lead to accelerated eutrophication of surface water. Because the ...

Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

This study presents an excavation method for investigating subsurface hydrological, geochemical, and microbiological heterogeneity of a soil lysimeter. The lysimeter simulates an artificial hillslope which was initially under homogeneous condition and had been subjected to approximately 5,000 mm of water over eight cycles of irrigation in an 18-month period.

土壤蒸渗仪开挖加之水文，地球化学和微生物调查

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled ...

Measurement of the Rheology of Crude Oil in Equilibrium with CO2 at Reservoir Conditions

A rheometer system to measure the rheology of crude oil in equilibrium with carbon dioxide (CO2) at high temperatures and pressures is described. The system comprises a high-pressure rheometer which is connected to a circulation loop. The rheometer has a rotational flow-through measurement cell with two alternative geometries: coaxial cylinder and double gap. The circulation loop contains a mixer, to bring the crude oil sample into equilibrium with CO2, and a gear pump that transports the mixture from the mixer to the rheometer and recycles it back to the mixer. The CO2 and crude oil are brought to equilibrium by stirring and circulation and the rheology of the saturated mixture is measured by the rheometer. The system is used to measure the rheological properties of Zuata crude oil (and its toluene dilution) in equilibrium with CO2 at elevated pressures up to 220 bar and a temperature of 50 &#176;C. The results show that CO2 addition changes the oil rheology significantly, initially reducing the viscosity as the CO2 pressure is increased and then increasing the viscosity above a threshold pressure. The non-Newtonian response of the crude is also seen to change with the addition of CO2.

Measurement of the Rheology of Crude Oil in Equilibrium with CO2 at Reservoir Conditions

A method for measuring the rheology of crude oil in equilibrium with carbon dioxide at reservoir conditions is presented.

与CO平衡的原油流变学测量<sub&gt; 2</sub&gt;在水库条件

A rheometer system to measure the rheology of crude oil in equilibrium with carbon dioxide (CO2) at high temperatures and pressures is described. The ...

Measuring and Mapping Patterns of Soil Erosion and Deposition Related to Soil Carbonate Concentrations Under Agricultural Management

Spatial patterns of soil erosion and deposition can be inferred from differences in ground elevation mapped at appropriate time increments. Such changes in elevation are related to changes in near-surface soil carbonate (CaCO3) profiles. The objective is to describe a simple conceptual model and detailed protocol for repeatable field and laboratory measurements of these quantities. Here, accurate elevation is measured using a ground-based differential global positioning system (GPS); other data acquisition methods could be applied to the same basic method. Soil samples are collected from prescribed depth intervals and analyzed in the lab using an efficient and precise modified pressure-calcimeter method for quantitative analysis of inorganic carbon concentration. Standard statistical methods are applied to point data, and representative results show significant correlations between changes in soil surface layer CaCO3 and changes in elevation consistent with the conceptual model; CaCO3 generally decreased in depositional areas and increased in erosional areas. Maps are derived from point measurements of elevation and soil CaCO3 to aid analyses. A map of erosional and depositional patterns at the study site, a rain-fed winter wheat field cropped in alternating wheat-fallow strips, shows the interacting effects of water and wind erosion affected by management and topography. Alternative sampling methods and depth intervals are discussed and recommended for future work relating soil erosion and deposition to soil CaCO3.

Spatial patterns of soil erosion and deposition can be inferred from differences in ground elevation mapped at appropriate time increments. Such changes in elevation are related to changes in near-surface soil carbonates. Repeatable methods for field and laboratory measurements of these quantities and data analysis methods are described here.

农业经营条件下土壤侵蚀和沉积与土壤碳酸盐浓度关系的测量与制图

Spatial patterns of soil erosion and deposition can be inferred from differences in ground elevation mapped at appropriate time increments. Such changes ...

Wastewater Irrigation Impacts on Soil Hydraulic Conductivity: Coupled Field Sampling and Laboratory Determination of Saturated Hydraulic Conductivity

Since the early 1960s, an alternative wastewater discharge practice at The Pennsylvania State University has been researched and its impacts monitored. Rather than discharging treated wastewater to a stream, and thereby directly impacting the stream quality, the effluent is applied to forested and cropped land managed by the University. Concerns related to reductions in soil hydraulic conductivity occur when considering wastewater reuse. The methodology described in this manuscript, matching soil sample size with the size of the laboratory-based hydraulic conductivity measurement apparatus, provides the benefits of a relatively rapid collection of samples with the benefits of controlled laboratory boundary conditions. The results suggest that there may have been some impact of wastewater reuse on the soil&#39;s ability to transmit water at deeper depths in the depressional areas of the site. Most of the reductions in the soil hydraulic conductivity in the depressions appear to be related to the depth from which the sample was collected, and by inference, associated with the soil structural and textural differences.

Here we present a methodology which matches a soil sample size and a hydraulic conductivity measurement device to prevent the so-called wall flow along the inside of the soil container from being erroneously included in water flow measurements. Its use is demonstrated with samples collected from a wastewater irrigation site.

污水灌溉对土壤水力电导率的影响: 耦合场取样与饱和水力电导率的实验室测定

Since the early 1960s, an alternative wastewater discharge practice at The Pennsylvania State University has been researched and its impacts monitored. ...

Evaluating Dryocosmus Kuriphilus-induced Damage on Castanea Sativa

Dryocosmus kuriphilus Yasumatsu has become a major pest for Castaneasativa since its arrival in Europe. Its galling activity results in the formation of different gall types and prevents the development of normal shoots. Repeated and uncontrolled attacks cause, besides the production of galls and the attendant gall-related reduction in leaf area, progressive corruption of the branch architecture, including the death of branch parts, and an increase in dormant bud activation. Thus far, there have been few attempts to quantify branch architecture damage. Further, the different methods for assessing infestation degree (MAID) that have been developed focus only on the galls' presence and abundance.
Using the leaf area to sapwood area relationship as a green biomass indicator, we developed in a previous study a damage composite index (DCI) that takes into account the most important branch architectural features, allowing for realistic damage assessment during the entire epidemic process. 
The aim of this study is to present this novel method and highlight differences in the damage description with respect to other broadly used indices. Results show how the DCI depicts branch damage better, especially during the epidemic peak, compared to MAID, which tend to underestimate it. We conclude by suggesting how to properly evaluate the overall impact of the pest by means of our composite damage index, the infestation degree using classic methods, and crown transparency evaluations.

Evaluating Dryocosmus Kuriphilus-induced Damage on Castanea Sativa

It is common practice to assess the damage caused by Dryocosmus kuriphilus by considering the abundance of galls alone rather than by also taking related branch corruption into consideration. We propose a composite damage index that takes into account the most important branch features, thus enabling more realistic damage assessment.

栗瘿栗瘿致锥害的评价

Dryocosmus kuriphilus Yasumatsu has become a major pest for Castaneasativa since its arrival in Europe. Its galling activity results in the formation of ...