We thank Ty P.A. Ferr&#233;, Till Volkman, Edwin Donker, Mauricio Vera for helping us during the excavation, and Triffon J. Tatarin, Manpreet Sahnan and Edward Hunt for their help in sample analysis. This work was carried out at Biosphere 2, University of Arizona and funded by National Science Foundation grant EAR_1344552 and Honors Research Program of Biosphere 2.

1，设计一个采样矩阵，确保蒸渗仪的系统全面的采样<ol><li>划分蒸渗成固定长度，宽度和深度的体素。 <ol><li>使用欧几里德空间坐标系和除以沿每个方向（X，Y和Z）的总距离成相等的间隔有足够的数量。考虑丢弃蒸渗仪的墙壁附近的土壤，以避免边界效应。 注:沿四个壁5cm的缓冲器在本实验中，以避免边界效应被采用，同时确保土壤的收集的体积是足够的。 </li><li>分配每个样品独特的XYZ位置，并确定为一个像素。 注:在此挖掘，X表示沿着斜坡的宽度位置，Y代表沿斜坡的长度位置，而ž沿着斜坡的深度表示位置。每个维中的时间间隔的大小决定的宽度，长度和体素的深度。˚Figure 2显示了与确定为XYZ系统原点选择沿空闲间隔后蒸渗仪的划分。在目前的开挖方案的部门有两个沿Y和Z方向9间隔在X方向4个间隔，产生共为10厘米×20厘米×10cm的尺寸（ 图3）324像素。 注意:所选择的取样策略确保了整个系统均匀地与传感器的损害最小采样。每个体素（1-2厘米）的边界被丢弃向相邻像素限制交叉污染。此外，体素的尺寸确保有足够的土壤材料可用于微生物，地球化学以及在每个体素水文样品收集。 </li></ol></li></ol><img alt="图1" src="/files/ftp_upload/54536/54536fig1.jpg" /> 蒸渗仪图1.侧视，从渗水发蒸渗仪观CE。也可见是在四个角三个传感器区域（白色聚氯乙烯管）沿着所述斜坡和喷水灭火系统。 <img alt="图2" src="/files/ftp_upload/54536/54536fig2.jpg" /> 图2.采样方案。沿着XYZ。A. X尺寸蒸渗仪的采样方案将宽到每个10厘米4个部分，而划分Ÿ长度为20cm的B. z方向指示的深度和分为9层10厘米深。 5厘米一直在蒸渗仪边缘的边界被确定，以防止可能会表现出边界效应样本的采集。 <a href="https://www.jove.com/files/ftp_upload/54536/54536fig2large.jpg" target="_blank">请点击此处下载此文件。</a> <img alt="图3" src="/files/ftp_upload/54536/54536fig3.jpg" /> 图3.三-D一个体素的imensional表示。沿蒸渗的XYZ表平面中的一个体素的视觉示意图。整个斜坡分为324像素等，每个像素描绘了一次抽样单位。 <a href="https://www.jove.com/files/ftp_upload/54536/54536fig3large.jpg" target="_blank">请点击此处下载此文件。</a> 2.添加亮蓝FCF染料来追踪水分入渗坡面<ol><li>在土壤表面应用亮蓝染料，足以覆盖顶部105厘米沿Y方向的表面。盖上塑料布残土。 <ol><li>选择的浓度（这里是10克/升），以保证对黑色玄武岩土壤的对比。染料添加到灌溉系统舱，并用水稀释至所需的浓度。 </li><li>决定基于该渗透前的期望深度和由灌溉系统供给的速率灌溉的持续时间。 注:对于这项研究中，我20分钟（ 图4）之前，挖掘30毫米/ hr的rrigation率被认为是为了在第一几厘米，以确定水渗入的异质模式就足够了。 </li><li>经过染料的应用，给时间渗透到停止，蒸渗仪内的水分状态达到平衡。在这项研究中，经过一段时间的应用染料和发掘之间的10小时（过夜）的是适当的。 </li></ol></li></ol> 3.体素的划界<ol><li>附加测量沿着斜坡的长度胶带体素划分期间提供指导的原位参考系统。 </li><li>标记每个土壤体素与测量带的帮助下的尺寸。绘制用于 ​​使用铝-刀片护罩和塑料油灰刀（ 图4）每层网格线。丢弃的边界材料（从每个隔壁5厘米防止边界效应）。 </li></ol> 图4.蒸渗仪的顶视图，该视图显示层2的染色表面（10厘米深）。土壤表面上绘制以辅助取样网格也是可见的，与在微生物样品收集后的各体素芯孔区域沿。 4.微生物样品采集<ol><li>从每个像素前的水文地球化学收集样品微生物分析无菌操作，防止样品的交叉污染。确保新手套通过进行挖掘，以从人体皮肤减少污染所有成员佩戴。 </li><li>使用直径为1cm和20厘米高和薄刮刀微生物样品收集的土壤取样器。清洁取样管并用蒸馏水锅铲，擦干用干净的纸巾，并与使用喷雾瓶75％乙醇冲洗干净。允许取样器和抹刀风干。 </li><li>说明C各样品的ollection时间。使用取样器核心在每个体素位置为10厘米的深度，并且刮刀清空土壤样品引入预消毒的塑料袋（ 图5）。小心开袋之前，为了沉积样品。手工匀化样品袋。 </li><li>存储在冰冷却器样品袋采样期间，并尽快转移到-80℃冷冻机中。 </li></ol><img alt="图5" src="/files/ftp_upload/54536/54536fig5.jpg" /> 图5.微生物样本采集，为20厘米×1厘米，无菌袋，和抹刀一个小的手持式取样器的微生物取样过程中显示在这里。 <a href="https://www.jove.com/files/ftp_upload/54536/54536fig5large.jpg" target="_blank">请点击这里下载此文件。</a> 5.地球化学和水文样品采集<ol><li>在X和Y PL照片染地区开挖的地方观察染料深处期间ANES。使用色卡来提供用于彩色观察（ 图6）的参考。确保适当的自然采光存在正确记录颜色强度。 </li><li>在开始测量前校准便携式X射线荧光光谱仪（pXRF）每天。用于校准和测量的细节，见生产商的说明13（ 图7）。简要地说，放置在支架上的仪器，并直接指向波束窗口到工厂金属珠。选择"校准"并且等待30秒，以允许完成校准。 <ol><li>服用每次测量前清洁束窗口。测量一式三份的每个体素的表面在三个不同的位置。放置在土壤表面上的pXRF仪器并等待90秒，以允许完成测量。 注:X射线可以通过在光束方向的长距离穿透。因此，ensu再次，只有经过培训的人员处理设备，并保持适当的安全协议。 </li></ol></li></ol><img alt="图6" src="/files/ftp_upload/54536/54536fig6.jpg" /> 图6.色卡遵循染料渗入。可见染料渗透每个位置与作为基准的色卡拍照。 <a href="https://www.jove.com/files/ftp_upload/54536/54536fig6large.jpg" target="_blank">请点击此处下载此文件。</a> <img alt="图7" src="/files/ftp_upload/54536/54536fig7.jpg" /> 图7.便携式X射线荧光光谱仪。手持pXRF定位在体素的表面。测量在每个体素的表面上的三个不同位置记录，然后取平均值。 <ol start="3"><li>干净的金属芯（高度= 3厘米，直径= 5.7Hz厘米）和聚碳酸酯共水库（高度= 6厘米，直径= 5.7Hz厘米）对堆积密度（BD）和所需的体素，分别（ 图8）的水力传导率测量（KSAT）。 </li><li>纵向金属核和核聚碳酸酯（垂直KSAT）插入注意不要损坏传感器或传感器导线所需的体素。轻轻敲打芯进入土壤，小心使用的平坦表面，如核心和锤之间的木材块，以便最小化干扰的土壤做到这一点。此外，一旦芯是中途进入土壤，放置一个第二芯的第一芯的顶端。放置在第二芯的顶部的木块，直到第一芯嵌入在与芯轮辋仍然可见土壤轻轻锤块。 </li><li>作为体素的侧面具有连续挖掘开辟了插入水平KSAT芯。如步骤5.4中提到，以尽量减少压实使用木块和第二核心。 </li><li>请注意，以确保像素被抽样从边界和相邻体素之前地球化学样品采集隔离。为此使用塑料油灰刀，随后手持式镘刀围绕金属或聚丙烯芯土壤样品采集到标地球化学（GC）样品袋中，直到核心可以轻松卸下来（ 例如 ， 图9A，B）。 </li></ol><img alt="图8" src="/files/ftp_upload/54536/54536fig8.jpg" /> 图8.堆积密度和水力传导芯。聚丙烯芯（左）被用于收集垂直和水平水力传导率的样品而金属芯（右）用于收集堆积密度的样品。 <img alt="图9" src="/files/ftp_upload/54536/54536fig9.jpg" /> 图9.体素的划分。塑料油灰刀被用来（A）隔离前（B）地球化学，容重和水力传导核心种质像素的界限。 <a href="https://www.jove.com/files/ftp_upload/54536/54536fig9large.jpg" target="_blank">请点击此处下载此文件。</a> <ol start="7"><li>取出金属芯，从两端刷掉多余的材料，并从核心传递样品标记BD样品袋中。称重每个样品袋样品并记录的总重量。 </li><li>取出聚丙烯核心。盖两侧用红色塑料瓶盖和标签垂直的聚丙烯核心是"V"和水平的聚丙烯核心为"H"之后样品编号。 </li><li>从体素到GC样品袋收集剩余的物质，留下一对土壤的几厘米在所有四个侧面，以防止与下一个体素的交叉污染。 </li><li>从步骤重复5.1到5.9的体素的一层中的其余部分。 </li><li>一旦从一层的所有像素已经完成后，重复步骤3.2至5.10的后续层。 注意:步骤5.1的需求，只对具有可见染料的体素执行。参阅图10可视化的体素突出显示从每个体素采集的所有样本的代表图。 </li> <li></li></ol><img alt="图10" src="/files/ftp_upload/54536/54536fig10.jpg" /> 图10.代表性体素，红色虚线表示芯收集微生物样品，绿色虚线表示水平水力传导率芯，黄色划线表示垂直水力传导芯，紫色虚线表示堆积密度芯和蓝色椭圆边界指示剩余从素样品被用于地球化学分析， <a href="https://www.jove.com/files/ftp_upload/54536/54536fig10large.jpg" target="_blank">请点击此处下载该文件。</a> &lt;/ P&gt; 6.样品分析<ol><li>收集了微生物样本使用分析分子（土壤中微生物DNA提取）14和培养（异养平板计数）15的分析。使用定量聚合酶链反应（定量PCR）16，以及高通量基因测序实验17,18提取的DNA。 </li><li>收集了地球化学使用的样品分析来衡量地球化学性质包括pH值（US EPA方法150.2），电导率（EC）（US EPA方法120.1），碳和氮的含量（US EPA方法415.3，元素19的连续提取的群众，和X射线衍射（XRD）和扩展X射线吸收精细结构（EXAFS）光谱按照斯坦福同步加速器辐射实验室规格，来调查矿物变换。 </li><li>使用收集用于实验室实验水文分析岩芯样品，如容重20和水力传导系数21。 </li></ol>

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Discuss. 5 (2), 1043-1065 (2008).</li><li>Gleeson, T., Paszkowski, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perceptions+of+scale+in+hydrology:+what+do+you+mean+by+regional+scale?.">Perceptions of scale in hydrology: what do you mean by regional scale?.</a> Hydrol. Sci. J. 00, 1-9 (2013).</li><li>Molins, S., Trebotich, D., Steefel, C. I., Shen, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+investigation+of+the+effect+of+pore+scale+flow+on+average+geochemical+reaction+rates+using+direct+numerical+simulation.">An investigation of the effect of pore scale flow on average geochemical reaction rates using direct numerical simulation.</a> Water Resour. Res. 48, W03527 (2012).</li><li>Fierer, N., Lennon, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+generation+and+maintenance+of+diversity+in+microbial+communities.">The generation and maintenance of diversity in microbial communities.</a> Am. J. Bot. 98 (3), 439-448 (2011).</li><li>Niu, G. Y., Pasetto, D., Scudeler, C., Paniconi, C., Putti, M., Troch, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+an+extreme+rainfall-runoff+event+at+the+Landscape+Evolution+Observatory+by+means+of+a+three-dimensional+physically-based+hydrologic+model.">Analysis of an extreme rainfall-runoff event at the Landscape Evolution Observatory by means of a three-dimensional physically-based hydrologic model.</a> Hydrol. Earth Syst. Sci. Discuss. 10, 12615-12641 (2013).</li><li>Marteinsson, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microbial+colonization+in+diverse+surface+soil+types+in+Surtsey+and+diversity+analysis+of+its+subsurface+microbiota.">Microbial colonization in diverse surface soil types in Surtsey and diversity analysis of its subsurface microbiota.</a> Biogeosciences. 12, 1191-1203 (2015).</li><li>Orcutt, B. N., Sylvan, J. B., Rogers, D. R., Delaney, J., Lee, R. W., Girguis, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+fixation+by+basalt-hosted+microbial+communities.">Carbon fixation by basalt-hosted microbial communities.</a> Front. Microbiol. 6, 00904 (2015).</li><li>Wu, L., Jacobson, A. D., Chen, H. C., Hausner, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+elemental+release+during+microbe-basalt+interactions+at+T=28&#176;C.">Characterization of elemental release during microbe-basalt interactions at T=28&#176;C.</a> Geochim. Cosmochim. Acta. 71, 2224-2239 (2007).</li></ol>

The authors have nothing to disclose.

景观进化是水文，地球化学和生物过程12的累积效应。这些过程控制流量以及水和元件运输，并在不断发展的景观生物地球化学反应。然而，捕捉交互同时要求精确协调的实验设计和抽样。此外，研究早期景观演化是自然系统困难，用有限的能力来识别"零时间"的条件。文献报道其进行测量植物根系密度23，而灌溉和挖掘基于现场的办法是由Graham等 24和 ​​安德森<em...

土壤和景观动态由物理，化学的复杂的相互作用，和生物过程1型。水流量，地球化学风化和生物活性塑造景观的整体发展成一个稳定的生态系统中2,3。虽然表面的变化都在地下区域景观4的最显着的特征，水文地球化学的认识累积效应，和微生物方法是了解潜在力量塑造景观2至关重要。未来气候情景摄惊慌失措进一步进化景观5的可预见性和模式。因此，它成为对景观尺度6小规模的过程链接到他们大型的表现是一个挑战。传统的短期实验室实验或与未知的初始条件和时间变化迫使功亏一篑捕捉个自然景观实验Ë固有景观演变的异质性。另外，由于强非线性耦合，它是很难预测在异构系统7从水文模拟生物地球化学的变化。在这里，我们描述了一种新的实验方法来挖掘已知初始条件完全控制和监测土坡。我们的挖掘和取样程序的目的是捕获沿其长度和深度的坡面的显影异质性，以提供全面的数据集来调查水力生物地球化学相互作用以及它们对土壤形成过程的影响的目的。 在自然界中发现水文系统远远不是静态的时间，在发生了大范围的空间和时间尺度3的水文响应变化。沿着风景流动通道的空间结构决定的速度，程度和地球化学反应和生物殖民化推动的分布风化，运输和溶质和沉积物的沉淀，和土壤结构的进一步发展。因此，结合从土壤学，地球物理和生态知识转化为理论和实验设计，评估水文过程，提高水文预测已建议8,9。景观演变也由地下的生物地球化学过程与水动力学，土壤发育过程中元素的迁移，并结合由空气，水矿物表面和微生物10的反应所带来的矿物转变的影响。因此，为一个变化的领域内研究地球化学热点的发展是重要的。此外，关键是为了了解复杂的景观发展的动态初始土壤形成过程中涉及的地球化学风化图案，水文过程和微生物的签名。土壤发生的具体过程管辖由气候，生物输入，浮雕和时间上的特定母材的综合影响。该实验的目的是要解决的条件，其中下在母材通过用浮雕（包括斜率和深度）相关的水文和地球化学变化支配风化的非均质性，并是受环境梯度（ 即 ，氧化还原电位）驱动在微生物活性相关的变异母体材料，气候和时间保持不变。对于微生物的活性，土壤中的微生物是重要组成部分，而且对景观稳定性11深远的影响。它们在土壤结构，营养元素的生物地球化学循环和植物生长至关重要的作用。因此，有必要了解这些生物体如风化司机，土壤发生，和景观形成过程的重要性，同时识别的水文流动路径和地球化学我们的倒数效果athering对微生物群落结构和多样性。这可以通过在一个不断发展的景观的水文地球化学特征也正在研究并行研究微生物群落多样性的空间异质性来实现。 在这里，我们提出了一个土壤蒸渗仪，操作上名为miniLEO，设计模仿设在生物圈2号（亚利桑那大学）的景观演变天文台（LEO）的大型零阶盆地模型的挖掘过程。该miniLEO目的是为了查明从累计异构水文生物地球化学过程所产生的小规模的景观演化模式。它是一个蒸渗2米长，0.5米宽，并在高度1米，以及10°的斜面（ 图1）。此外，蒸渗的壁是绝缘的，涂有非生物降解的两部分组成的环氧底漆和骨料填充脂族氨基甲酸酯涂层，以避免潜在的污染或浸出从蒸渗帧到土壤中的金属。在蒸渗仪中弥漫着被从火山口梅里亚姆在亚利桑那州北部关联晚更新世火山灰的存款中提取碎玄武岩。加载的玄武岩材料是相同的大得多的LEO实验中使用的材料。矿物组合物，粒度分布，和液压属性由潘高等人 12所述。下坡渗水面带小孔的塑料屏幕（0.002米直径的孔，14％的孔隙率）的衬里。该系统配有传感器，例如水含量和温度传感器，两种类型的水势传感器，土壤 - 水取样，液压重量平衡，导电性的探针，以及压力传感器，以确定水位高度。在蒸渗仪被用于灌溉前的开挖18个月。 此次发掘是在方法上细致，旨在回答两大问题:（1）什么水文，地球化学和微生物的签名可以在斜坡的长度和深度可以观察到相对于模拟降雨条件和（2）是否水力生物地球化学过程之间的关系，并反馈的坡面发生可以从推断个人签名。除了实验装置和发掘过程中，我们提出了关于如何申请类似的发掘协议兴趣研究加之地球系统动力学和/或土壤发展进程的研究人员具有代表性的数据和建议。

<table border="0" cellpadding="0" cellspacing="0" width="1632">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Measuring tape</td>
			<td style="width:71px;">Any</td>
			<td style="width:153px;">Any</td>
			<td style="width:1192px;">Preventing cross-contamination of samples&#160; is crucial. Therefore, it is helpful to have multiple putty knives to isolate voxel boundary.</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:216px;">Brilliant Blue dye</td>
			<td style="width:71px;">Waldeck GmBH &#38;Co&#160;</td>
			<td style="width:153px;">B0770</td>
			<td>Rulers can be used to draw grids. The sampling strategy can be modified based on individual experiments.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Soil Corer</td>
			<td style="width:71px;">AMS</td>
			<td style="width:153px;">56975</td>
			<td>Any commercially manufactured Brilliant Blue dye can be used.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">75% Ethanol</td>
			<td style="width:71px;">Any</td>
			<td style="width:153px;">Any</td>
			<td>A Nikon D90 camera and 50mm lens were used for photography. Any high resolution camera and lens can be used for this purpose.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Spray Bottle</td>
			<td style="width:71px;">Any&#160;</td>
			<td style="width:153px;">Any</td>
			<td>Use of dye and color card is subjective to individual experiments and/or research questions.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Spatula</td>
			<td style="width:71px;">Any&#160;</td>
			<td style="width:153px;">Any</td>
			<td>Gardening gloves may be used if handling of corer becomes tedious.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Gloves</td>
			<td style="width:71px;">Any&#160;</td>
			<td style="width:153px;">Any</td>
			<td>Ensure microbiology samples are kept in ice during sampling and frozen as soon as possible.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">KimWipes</td>
			<td style="width:71px;">KimTech Science</td>
			<td style="width:153px;">Any</td>
			<td>Water can be used to wash soil corer, prior to sanitizing with ethanol.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Sterile Sample bags</td>
			<td style="width:71px;">Fisher Scientific&#160;</td>
			<td style="width:153px;">Whirl-Pak 4 OZ. 24 OZ</td>
			<td>Keep buckets and dustpans handy to facilitate removal of waste soil.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Color Card</td>
			<td style="width:71px;">Any</td>
			<td style="width:153px;">Any</td>
			<td>The original design of miniLEO has various sensors embedded in the lysimeter. Such sensors may or may not be necessary based on the scope of individual experimental design.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">X-ray Fluoresce Spectrophotmeter</td>
			<td style="width:71px;">XRF, OLYMPUS</td>
			<td style="width:153px;">DS-2000 Delta XRF</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Polypropylene cores</td>
			<td style="width:71px;">Any</td>
			<td style="width:153px;">Any</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Metal cores&#160;</td>
			<td style="width:71px;">Any&#160;</td>
			<td style="width:153px;">Any</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Caps for polypropylene cores</td>
			<td style="width:71px;">Any</td>
			<td style="width:153px;">Any</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Hammer</td>
			<td style="width:71px;">Any&#160;</td>
			<td style="width:153px;">Any</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Plastic putty knives</td>
			<td style="width:71px;">Any&#160;</td>
			<td style="width:153px;">Any</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Face masks</td>
			<td style="width:71px;">Any&#160;</td>
			<td style="width:153px;">Any</td>
			<td></td>
		</tr>
	</tbody>
</table>

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.

像素尺寸确保了样本的采集水文，地球化学和微生物学的测量。开挖过程产生了324内核的微生物分析，972 pXRF数据点，324地球化学样品袋，180 KSAT样品（128垂直和水平方向52）和311容重样本。亮蓝染料的优先流还观察到的表面的小于30厘米的深度。从蒸渗仪的单一的垂直切片一组有代表性的样品81被选为初步分析。选择的样品来自于斜率X = 2的位置，而Y和Z体素从0-8范围。从DN...

Watch this Scientific Journal Video about Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations at JoVE.com

用于水文、地球化学和微生物耦合研究的土壤蒸渗仪挖掘 |环境 |视频

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

这项研究提出调查地下的水文，地球化学和土壤蒸渗仪的微生物异质性挖掘方法。在蒸渗仪模拟人工坡面它最初是均匀的条件下，并在18个月内曾受到近5000毫米的水灌溉超过8个周期。

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 ...

soil-lysimeter-excavation-for-coupled-hydrological-geochemical

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Speciation and Diversity

SCIENTISTS IN ACTION

10.6K 次观看.  University of Arizona. 这项研究提出调查地下的水文，地球化学和土壤蒸渗仪的微生物异质性挖掘方法。在蒸渗仪模拟人工坡面它最初是均匀的条件下，并在18个月内曾受到近5000毫米的水灌溉超过8个周期。 

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

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

Integrated Field Lysimetry and Porewater Sampling for Evaluation of Chemical Mobility in Soils and Established Vegetation

Potentially toxic chemicals are routinely applied to land to meet growing demands on waste management and food production, but the fate of these chemicals is often not well understood. Here we demonstrate an integrated field lysimetry and porewater sampling method for evaluating the mobility of chemicals applied to soils and established vegetation. Lysimeters, open columns made of metal or plastic, are driven into bareground or vegetated soils. Porewater samplers, which are commercially available and use vacuum to collect percolating soil water, are installed at predetermined depths within the lysimeters. At prearranged times following chemical application to experimental plots, porewater is collected, and lysimeters, containing soil and vegetation, are exhumed. By analyzing chemical concentrations in the lysimeter soil, vegetation, and porewater, downward leaching rates, soil retention capacities, and plant uptake for the chemical of interest may be quantified. Because field lysimetry and porewater sampling are conducted under natural environmental conditions and with minimal soil disturbance, derived results project real-case scenarios and provide valuable information for chemical management. As chemicals are increasingly applied to land worldwide, the described techniques may be utilized to determine whether applied chemicals pose adverse effects to human health or the environment.

Field lysimetry and porewater sampling allow researchers to evaluate the fate of chemicals applied to soils and established vegetation. The goal of this protocol is to demonstrate how to install required instrumentation and collect samples for chemical analysis during integrated field lysimetry and porewater sampling experiments.

综合外地Lysimetry和孔隙水采样的化学活动性土壤的评价和植被成立

Potentially toxic chemicals are routinely applied to land to meet growing demands on waste management and food production, but the fate of these chemicals ...

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 ...

A Gusseted Thermogradient Table to Control Soil Temperatures for Evaluating Plant Growth and Monitoring Soil Processes

Thermogradient tables were first developed in the 1950s primarily to test seed germination over a range of temperatures simultaneously without using a series of incubators. A temperature gradient is passively established across the surface of the table between the heated and cooled ends and is lost quickly at distances above the surface. Since temperature is only controlled on the table surface, experiments are restricted to shallow containers, such as Petri dishes, placed on the table. Welding continuous aluminum vertical strips or gussets perpendicular to the surface of a table enables temperature control in depth via convective heat flow. Soil in the channels between gussets was maintained across a gradient of temperatures allowing a greater diversity of experimentation. The gusseted design was evaluated by germinating oat, lettuce, tomato, and melon seeds. Soil temperatures were monitored using individual, battery-powered dataloggers positioned across the table. LED lights installed in the lids or along the sides of the gradient table create a controlled temperature chamber where seedlings can be grown over a range of temperatures. The gusseted design enabled accurate determination of optimum temperatures for fastest germination rate and the highest percentage germination for each species. Germination information from gradient table experiments can help predict seed germination and seedling growth under the adverse soil conditions often encountered during field crop production. Temperature effects on seed germination, seedling growth, and soil ecology can be tested under controlled conditions in a laboratory using a gusseted thermogradient table.

Traditional thermogradient tables create a range of temperatures across the surface. Welding gussets perpendicular to the surface of a thermogradient table will control temperature in depth increasing possible research applications.

一个插角Thermogradient表来控制土壤温度为评估植物生长和监测土壤过程

Thermogradient tables were first developed in the 1950s primarily to test seed germination over a range of temperatures simultaneously without using a ...

Protocols for Quantifying Transferable Pesticide Residues in Turfgrass Systems

Plant canopies in established turfgrass systems can intercept an appreciable amount of sprayed pesticides, which can be transferred through various routes onto humans. For this reason, transferable pesticide residue experiments are required for registration and re-registration by the United States Environmental Protection Agency (USEPA). Although such experiments are required, limited specificity is required pertaining to experimental approach. Experimental approaches used to assess pesticide transfer to humans including hand wiping with cotton gloves, modified California roller (moving a roller of known mass over cotton cloth) and soccer ball roll (ball wrapped with sorbent strip) over three treated turfgrass species (creeping bentgrass, hybrid bermudagrass and tall fescue maintained at 0.4, 5 and 9 cm, respectively) are presented. The modified California roller is the most extensively utilized approach to date, and is best suited for use at low mowing heights due to its reproducibility and large sampling area. The soccer ball roll is a less aggressive transfer approach; however, it mimics a very common occurrence in the most popular international sport, and has many implications for nondietary pesticide exposure from hand-to-mouth contact. Additionally, this approach may be adjusted for other athletic activities with limited modification. Hand wiping is the best approach to transfer pesticides at higher mowing heights, as roller-based approaches can lay blades over; however, it is more subjective due to more variable sampling pressure. Utility of these methods across turfgrass species is presented, and additional considerations to conduct transferable pesticide residue research in turfgrass systems are discussed.

Transferable pesticide residue experiments in turfgrass systems are integral components of human risk exposure assessments. Experimental approaches to measure transferable residues should be adjusted to the human interaction of interest and turfgrass system dynamics. Three transferable pesticide residue protocols are presented and the suitability across three turfgrass systems is discussed.

协议在草坪系统量化转换农药残留

Plant canopies in established turfgrass systems can intercept an appreciable amount of sprayed pesticides, which can be transferred through various routes ...

Nanopore DNA Sequencing for Metagenomic Soil Analysis

This article describes the steps for construction of a DNA library from soil, preparation and use of the nanopore flow cell, and analysis of the DNA sequences identified using computer software. Nanopore DNA sequencing is a flexible technique that allows for rapid microbial genome sequencing to identify bacterial and viral species, to characterize bacterial strains, and to detect genetic mutations that confer resistance to antibiotics. The advantages of nanopore sequencing (NS) for life sciences include its low complexity, reduced cost, and rapid real-time sequencing of purified genomic DNA, PCR amplicons, cDNA samples, or RNA. NS is an example of "strand sequencing" which involves sequencing DNA by guiding a single stranded DNA molecule through a nanopore that is inserted into a synthetic polymer membrane. The membrane has an electrical current applied across it, so as the individual bases pass through the nanopore the electrical current is disrupted to varying degrees by the four nucleotide bases. The identification of each nucleotide occurs by detecting the characteristic modulation of the electrical current by the different bases as they pass through the nanopore. The NS system consists of a handheld, USB powered portable device and a disposable flow cell that contains a nanopore array. The portable device plugs into a standard laptop computer that reads and records the DNA sequence using computer software.

Nanopore technology for sequencing biomolecules has wide applications in the life sciences, including identification of pathogens, food safety monitoring, genomic analysis, metagenomic environmental monitoring, and characterization of bacterial antibiotic resistance. In this article, the procedure for metagenomic soil DNA sequencing for species identification using the nanopore sequencing technology is demonstrated.

基因土壤分析的纳米 DNA 测序

This article describes the steps for construction of a DNA library from soil, preparation and use of the nanopore flow cell, and analysis of the DNA ...

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. ...

Use of Principal Components for Scaling Up Topographic Models to Map Soil Redistribution and Soil Organic Carbon

Landscape topography is a critical factor affecting soil formation and plays an important role in determining soil properties on the earth surface, as it regulates the gravity-driven soil movement induced by runoff and tillage activities. The recent application of Light Detection and Ranging (LiDAR) data holds promise for generating high spatial resolution topographic metrics that can be used to investigate soil property variability. In this study, fifteen topographic metrics derived from LiDAR data were used to investigate topographic impacts on redistribution of soil and spatial distribution of soil organic carbon (SOC). Specifically, we explored the use of topographic principal components (TPCs) for characterizing topography metrics and stepwise principal component regression (SPCR) to develop topography-based soil erosion and SOC models at site and watershed scales. Performance of SPCR models was evaluated against stepwise ordinary least square regression (SOLSR) models. Results showed that SPCR models outperformed SOLSR models in predicting soil redistribution rates and SOC density at different spatial scales. Use of TPCs removes potential collinearity between individual input variables, and dimensionality reduction by principal component analysis (PCA) diminishes the risk of overfitting the prediction models. This study proposes a new approach for modeling soil redistribution across various spatial scales. For one application, access to private lands is often limited, and the need to extrapolate findings from representative study sites to larger settings that include private lands can be important.

Landscape processes are critical components of soil formation and play important roles in determining soil properties and spatial structure in landscapes. We propose a new approach using stepwise principal component regression to predict soil redistribution and soil organic carbon across various spatial scales.

利用主成分扩展地形模型绘制土壤再分配和土壤有机碳

Landscape topography is a critical factor affecting soil formation and plays an important role in determining soil properties on the earth surface, as it ...

Combined Size and Density Fractionation of Soils for Investigations of Organo-Mineral Interactions

Combined size and density fractionation (CSDF) is a method used to physically separate soil into fractions differing in particle size and mineralogy. CSDF relies on sequential density separation and sedimentation steps to isolate (1) the free light fraction (uncomplexed organic matter), (2) the occluded light fraction (uncomplexed organic matter trapped in soil aggregates) and (3) a variable number of heavy fractions (soil minerals and their associated organic matter) differing in composition. Provided that the parameters of the CSDF (dispersion energy, density cut-offs, sedimentation time) are properly selected, the method yields heavy fractions of relatively homogeneous mineral composition. Each of these fractions is expected to have a different complexing ability towards organic matter, rendering this a useful method to isolate and study the nature of organo-mineral interactions. Combining density and particle size separation brings an improved resolution compared to simple size or density fractionation methods, allowing the separation of heavy components according to both mineralogy and size (related to surface area) criteria. As is the case for all physical fractionation methods, it may be considered as less disruptive or aggressive than chemically-based extraction methods. However, CSDF is a time-consuming method and furthermore, the quantity of material obtained in some fractions can be limiting for subsequent analysis. Following CSDF, the fractions may be analyzed for mineralogical composition, soil organic carbon concentration and organic matter chemistry. The method provides quantitative information about organic carbon distribution within a soil sample and brings light to the sorptive capacity of the different, naturally-occurring mineral phases, thus providing mechanistic information about the preferential nature of organo-mineral interactions in soils (i.e., which minerals, what type of organic matter).

Combined size and density fractionation (CSDF) is a method to physically separate soil into fractions differing in texture (particle size) and mineralogy (density). The purpose is to isolate fractions with different reactivities towards soil organic matter (SOM), in order to better understand organo-mineral interactions and SOM dynamics.

土壤联合粒径与密度的分离研究

Combined size and density fractionation (CSDF) is a method used to physically separate soil into fractions differing in particle size and mineralogy. CSDF ...