The authors are grateful to the staff of USDA-ARS Pasture Systems and Watershed Management Unit. David Otto was important to both the design and construction of the custom made drop hammer (aka 'The Intimidator'). Michael Reiner and Terry Troutman assisted in the collection and construction of the lysimeters reported in this study. Sarah Fishel, Charles Montgomery and Paul Spock performed all of the nutrient analyses reported in this manuscript.

1. Preparing the Materials
<ol>
	<li>Cut the main body of the lysimeter from 30.5 cm (12 inch) diameter (ID; nominal) schedule 80 PVC; this has a wall thickness of 1.9 cm (0.75 inch) (Figure 1a). Cut the length of the lysimeter body depending on the thickness of the soil layer(s) to be studied; here, use a 53 cm (21 inch) long body. Rout a 0.63 cm deep by 45&#176; bevel around the bottom end of the lysimeter to form a sharp leading edge on the inside wall of the lysimeter body to aid in cutting through...

<ol>
	<li>Patterson, P. H., Lorenz, E. S., Weaver, W. D., Schwart, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Litter+production+and+nutrients+from+commercial+broiler+chickens.">Litter production and nutrients from commercial broiler chickens.</a> J. Applied Poultry Res. 7 (3), 247-252 (1998).</li><li>Cullum, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Macropore+flow+estimations+under+no-till+and+till+systems.">Macropore flow estimations under no-till and till systems.</a> Catena. 78, 87-91 (2009).</li><li>Kladivko, E. J., 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=Nitrate+leaching+to+subsurface+drains+as+affected+by+drain+spacing+and+changes+in+crop+production+systems.">Nitrate leaching to subsurface drains as affected by drain spacing and changes in crop production systems.</a> J. Environ. Qual. 33, 1803-1813 (2004).</li><li>Persson, L., Bergstrom, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drilling+method+for+collection+of+undisturbed+soil+monoliths).">Drilling method for collection of undisturbed soil monoliths).</a> Soil Sci. Soc. Am. J. 55 (1), 285-287 (1991).</li><li>Belford, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collection+and+evaluation+of+large+soil+monoliths+for+soil+and+crop+studies.">Collection and evaluation of large soil monoliths for soil and crop studies.</a> J. Soil Sci. 30 (2), 363-373 (1979).</li><li>Dell, C. J., Kleinman, P. J. A., Schmidt, J. P., Beegle, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low+disturbance+manure+incorporation+effects+on+ammonia+and+nitrate+loss.">Low disturbance manure incorporation effects on ammonia and nitrate loss.</a> J. Environ. Qual. 41, 928-937 (2012).</li><li>Owens, L. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nitrate-nitrogen+concentrations+in+percolate+from+lysimeters+planted+to+a+legume-grass+mixture.">Nitrate-nitrogen concentrations in percolate from lysimeters planted to a legume-grass mixture.</a> J. Environ. Qual. 19, 131-135 (1990).</li><li>Zhu, Y., Fox, R. H., Toth, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Leachate+collection+efficiency+of+zero-tension+pan+and+passive+capillary+fiberglass+wick+lysimeters.">Leachate collection efficiency of zero-tension pan and passive capillary fiberglass wick lysimeters.</a> Soil Sci. Soc. Am. J. , (2002).</li><li>Jemison, J. M., Fox, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimation+of+zero-tension+pan+lysimeter+collection+efficiency.">Estimation of zero-tension pan lysimeter collection efficiency.</a> Soil Sci. 154, 85-94 (1992).</li><li>Corwin, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+a+simple+lysimeter-design+modification+to+minimize+sidewall+flow.">Evaluation of a simple lysimeter-design modification to minimize sidewall flow.</a> J. Contaminant Hydrology. 42 (1), 35-49 (2000).</li><li>Havis, R. N., Alberts, E. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nutrient+leaching+from+field+decomposed+corn+and+soybean+residue+under+simulated+rainfall.">Nutrient leaching from field decomposed corn and soybean residue under simulated rainfall.</a> Soil Sci. Soc. Am. J. 57, 211-218 (1993).</li><li>Bergstrom, L., Johanssson, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Leaching+of+nitrate+from+monolith+lysimeters+of+different+types+of+agricultural+soils.">Leaching of nitrate from monolith lysimeters of different types of agricultural soils.</a> J. Environ. Qual. 20, 801-807 (1991).</li><li>Lotter, D., Seidel, R., Liebhardt, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+performance+of+organic+and+conventional+cropping+systems+in+an+extreme+climate+year.">The performance of organic and conventional cropping systems in an extreme climate year.</a> Am. J. Alternative Agriculture. 18 (3), 146-154 (2003).</li><li>Moyer, J., Saporito, L., Janke, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design,+construction,+and+installation+of+an+intact+soil+core+lysimeter.">Design, construction, and installation of an intact soil core lysimeter.</a> Agronomy J. 88 (2), 253-256 (1996).</li><li>Stout, W. L., 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=Nitrate+leaching+from+cattle+urine+and+feces+in+northeast+US.">Nitrate leaching from cattle urine and feces in northeast US.</a> Soil Sci. Soc. Am. J. 61, 1787-1794 (1997).</li><li>Stout, W. L., Gburek, W. J., Schnabel, R. R., Folmar, G. J., Weaver, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Soil-climate+effects+on+nitrate+leaching+from+cattle+excreta.">Soil-climate effects on nitrate leaching from cattle excreta.</a> J. Environ. Qual. 27, 992-998 (1998).</li><li>Kleinman, P. J. A., Srinivasan, M. S., Sharpley, A. N., Gburek, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phosphorus+leaching+through+intact+soil+columns+before+and+after+poultry+manure+applications.">Phosphorus leaching through intact soil columns before and after poultry manure applications.</a> Soil Sci. 170 (3), 153-166 (2005).</li><li>Kleinman, P. J. A., Sharpley, A. N., Saporito, L. S., Buda, A. R., Bryant, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+manure+to+no-till+soils:+Phosphorus+losses+by+subsurface+and+surface+pathways.">Application of manure to no-till soils: Phosphorus losses by subsurface and surface pathways.</a> Nutr. Cycling Agroecosyst. 84, 215-227 (2009).</li><li>McDowell, R. W., Sharpley, A. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Approximating+phosphorus+release+to+surface+runoff+and+subsurface+drainage.">Approximating phosphorus release to surface runoff and subsurface drainage.</a> J. Environ. Qual. 30, 508-520 (2001).</li><li>McDowell, R. W., Sharpley, A. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phosphorus+losses+in+subsurface+flow+before+and+after+manure+application.">Phosphorus losses in subsurface flow before and after manure application.</a> Sci. Total Environ. 278, 113-125 (2001).</li><li>Brock, E. H., Ketterings, Q. M., Kleinman, P. J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phosphorus+leaching+through+intact+soil+cores+as+influenced+by+type+and+duration+of+manure+application.">Phosphorus leaching through intact soil cores as influenced by type and duration of manure application.</a> Nutr. Cycl. Agroecosyst. 77, 269-281 (2007).</li><li>Svanback, A., 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=Influence+of+soil+phosphorus+and+manure+on+phosphorus+leaching+in+Swedish+topsoils.">Influence of soil phosphorus and manure on phosphorus leaching in Swedish topsoils.</a> Nutr. Cycling Agroecosyst. 96, 133-147 (2013).</li><li>Feyereisen, G. W., 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=Effect+of+direct+incorporation+of+poultry+litter+on+phosphorus+leaching+from+coastal+plain+soils.">Effect of direct incorporation of poultry litter on phosphorus leaching from coastal plain soils.</a> J. Soil Water Cons. 65 (4), 243-251 (2010).</li><li>Williams, M. R., 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=Manure+application+under+winter+conditions:+Nutrient+runoff+and+leachate+losses.">Manure application under winter conditions: Nutrient runoff and leachate losses.</a> Trans. ASABE. 54 (3), 891-899 (2011).</li><li>Liu, J., Aronsson, H., Ul&#233;n, B., Bergstr&#246;m, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Potential+phosphorus+leaching+from+sandy+topsoils+with+different+fertilizer+histories+before+and+after+application+of+pig+slurry.">Potential phosphorus leaching from sandy topsoils with different fertilizer histories before and after application of pig slurry.</a> Soil Use Mgmt. 28, 457-467 (2012).</li><li>Kibet, L. C., 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=Transport+of+dissolved+trace+elements+in+surface+runoff+and+leachate+from+a+coastal+plain+soil+after+poultry+litter+application.">Transport of dissolved trace elements in surface runoff and leachate from a coastal plain soil after poultry litter application.</a> J. Soil Water Cons. 68 (3), 212-220 (2013).</li><li>Han, K., 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=Phosphorus+and+nitrogen+leaching+before+and+after+tillage+and+urea+application.">Phosphorus and nitrogen leaching before and after tillage and urea application.</a> J. Environ. Qual. 44, 560-571 (2014).</li><li>Day, P. R., Black, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=This+chapter+in+Methods+of+Soil+Analysis.+Part+1.+Physical+and+Mineralogical+Properties,+Including+Statistics+of+Measurement+and+Sampling.">This chapter in Methods of Soil Analysis. Part 1. Physical and Mineralogical Properties, Including Statistics of Measurement and Sampling.</a> American Society of Agronomy, Soil Science Society of America. , (1965).</li><li>Kleinman, P. J. A., 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=Phosphorus+leaching+from+agricultural+soils+of+the+Delmarva+Peninsula,+USA.">Phosphorus leaching from agricultural soils of the Delmarva Peninsula, USA.</a> J. Environ. Qual. 44 (2), 524-534 (2015).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lachat+Instruments.+Determination+of+nitrate/nitrite+in+surface+and+wastewaters+by+flow+injection+analysis.">Lachat Instruments. Determination of nitrate/nitrite in surface and wastewaters by flow injection analysis.</a> QuickChem Method. , (2003).</li></ol>

The authors declare no competing financial interests.

Important steps of lysimeter Collection
Leaching studies illustrate the influence of soil properties and manure management on nitrogen losses to shallow groundwater. Soil physical properties such as soil texture, aggregate structure and bulk density mediate the percolation of water and solutes. Accurately determining leachate volume and solute concentrations is dependent upon retaining the integrity of these soil physical properties during lysimeter collection by following these critical steps...

The Delmarva Peninsula borders the eastern shore of the Chesapeake Bay, and is the home to one of largest poultry production regions in the US. Roughly 600 million chickens and an estimated 750,000 tons of manure are generated from the production of these birds each year1. Most of the manure is used locally as a fertilizer amendment on agricultural fields. Because of historically high rates of manure application, nutrients such as nitrogen and phosphorus have accumulated in the soil and are now susceptible to off-site losses via subsurface leaching2. Much of the groundwater flow is directed toward an extensive network of ditches that ultimately drain to the Chesapeake Bay3. The nutrients carried to the Bay are linked to the decline in the Bay&#39;s health due to eutrophication4.
Connecting nutrient management with off-site losses of nutrients requires specialized tools to monitor hydrologic flows and associated nutrient transfers. Lysimeters represent a major category of instruments used to characterize and quantify the movement of nutrients through soils. Lysimeters have a long history of use in monitoring nutrient flow in percolating water5-7, from tension lysimeters that can be adjusted to counter soil matrix potential so that they better estimate plant available water, to zero-tension lysimeters that are more representative of processes occurring during free drainage. All approaches to lysimetery present inherent biases. For instance, some lysimeters are too small to fully represent spatially complex processes in natural soils, or are too large and expensive to provide good statistical replication of heterogeneous soils8. Further, pan lysimeters require soils above them to be saturated to collect leachate and are inefficient compared to tension lysimeters at measuring matrix flow9.
Closed lysimeter systems, such as zero-tension soil core lysimeters (also known as soil monolith lysimeters), greatly improve the confidence with which water budgets and associated pollutant budgets (e.g., nutrient budgets) are carried out10. These lysimeters are most representative when they contain intact cores of soil; lysimeters filled with repacked soils do not maintain the original structure, horizons and macropore connections that influence the transport of solutes and particulate compounds alike11,12. From an experimental stand point, approaches that facilitate greater replication of undisturbed soil conditions are advantageous, given the inherent spatial variability that exists in soil physical and chemical properties13.
Two preferred methods have been used for collecting intact soil core lysimeters: drop hammer and cutting head. The former has been more commonly performed, as it can be achieved with devices as simple as a sledge hammer (smaller lysimeters). When performed properly, soil core collection with a drop hammer has been shown to be relatively cost effective, especially when compared with other coring techniques. However, the sheer forces imposed by driving a lysimeter casing into the ground can cause smearing and compaction, producing conditions inside the lysimeter that are not representative of native soil and may even favor certain types of water movement (e.g., bypass flow, or flow along the soil core edge). As a result, some researchers have preferred the use of corers that cut away an intact soil with a drilling apparatus or other excavation device5.
Various materials have been used as casings for soil core lysimeters. Steel pipes and boxes are comparatively low cost, durable and readily available and can be used to collect larger lysimeters due to their strength14-17. However, while steel is satisfactory for evaluating the leaching of relatively unreactive compounds such as nitrate, the iron in steel reacts with phosphate and must therefore be coated or otherwise treated for the study of phosphorus leaching. Commonly, plastic casings are used to study phosphorus leaching, such as thick walled (Schedule 80) PVC pipe that can withstand the impact of a drop hammer (if used) and retain its structure when larger diameter soil cores are obtained (e.g., &#8805;30 cm)18-22.
In general, soil core lysimeters are analyzed ex situ. Once collected, soil core lysimeters may be installed in outdoor &#34;lysimeter farms&#34; where surrounding soil and above ground climates represent natural field conditions. For instance, in Sweden, the Swedish Agricultural University has maintained three separate lysimeter farms over the past three decades, analyzing pesticide fate-and-transport, long-term soil fertility trials, and management practices that can be scaled to 30 cm diameter intact cores23. Soil core lysimeters have also been subjected to indoor leaching experiments where there is greater control of climatic conditions24,25. Liu et al. used a rainfall simulator to regularly irrigate soil core lysimeters under an array of catch crops26. Kibet and Kun all employed hand irrigation techniques to study arsenic and nutrient leaching through soil cores27,28.
A variety of edaphic and hydrologic processes can be inferred from soil core lysimeters. Kun et al. (2015) used 30 cm diameter PVC column lysimeters to investigate nitrogen leaching after urea application28. By collecting leachate at different time intervals following an irrigation event, they were able to differentiate between rapid and gradual flows, with the former assumed to be dominated by macropore flow, and the later assumed to be dominated by matrix flow. Since urea is readily hydrolyzed when in contact with soil, they interpreted the presence of elevated urea concentrations in leachate collected shortly after urea application as evidence of macropore transport that bypassed the soil matrix. Over time, they detected elevated concentrations of different forms of nitrogen in leachate, tracking the transformation of applied urea to ammonium after initial hydrolysis, then the transformation of ammonium to nitrate with nitrification.
To illustrate considerations in designing, conducting and interpreting soil core lysimeter experiments, we carried out an investigation of four different soils found in the mid-Atlantic coastal plain of USA. The study measured leaching concentration and loss of nitrate before and after application of dry poultry manure (i.e., poultry &#34;litter&#34;)28. Nutrient losses from the application of poultry litter to soils are a key concern to the health of the Chesapeake Bay, and understanding the interaction of applied poultry litter and agricultural soil properties is needed to improve nutrient management recommendations. We present here a detailed method for extracting intact soil core lysimeters, tracking soil moisture, and interpreting differential nitrate leaching losses from these soils.
This experiment is part of a larger study conducted to assess nutrient leaching from agricultural soils of the Delmarva Peninsula, USA27,28. Soil core lysimeters were collected from sites in Delaware, Maryland and Virginia in 2010. Here we present unpublished results from these studies. Although initial experiments were conducted to assess phosphorus leaching, nitrate leaching from theses soils was also monitored.

Four common agricultural soils from the Atlantic coastal plain of the Chesapeake Bay Watershed were sampled: Bojac (coarse-loamy, mixed, semiactive, thermic Typic Hapludult); Evesboro (mesic, coated Lamellic Quartzipsamment); Quindocqua (fine-loamy, mixed, active, mesic Typic Endoaquult); Sassafras (fine-loamy, siliceous, semiactive, mesic Typic Hapludult). For each soil, horizon morphology was described from the profiles exposed by the excavation of the columns (Table 1). Surface textures of the soils ranged from sand (Evesboro) to loamy fine sand/sandy loam (Bojac and Sassafras) to silt loam (Quindocqua). Although all soils had been historically fertilized with poultry litter, none had been applied in the 10 months prior to the study. All soils had been in no-till corn production for at least one season prior to soil core lysimeter collection.

Following collection, soil core lysimeters were transported to the USDA-ARS simulatorium facility in State College, PA. There they were subject to indoor irrigation experiments (22-26 &#176;C) to assess nutrient leaching related to poultry litter application. Specifically, lysimeters were irrigated with 2 cm of water weekly for 8 weeks until nitrate in percolate was equilibrated between the soils. Poultry litter (dry poultry manure) was then applied to the surface of all soils at the rate of 162 kg ha-1 of total N. Irrigation was continued for 5 more weeks. Moisture sensors recorded volumetric moisture content at 5 minute intervals continuously, throughout the irrigation and leaching cycle. Leachate was collected after 24 hr and again 7 days later immediately prior to irrigation.
Leachate data from the soil core lysimeters were analyzed using simple descriptive statistics to illustrate differences in leachate quantity and quality between soils, as well as differences before and after litter application. Because soil moisture sensors were placed in only two of the replicate soil core lysimeters for each soil (Evesboro, Bojac, Sassafras, Quindocqua), statistics for soil moisture content were based on N = 2, whereas statistics for leachate depth, nitrate-N concentration and nitrate-N flux were derived from 10 soil core lysimeters for Evesboro, Bojac and Sassafras and 5 soil core lysimeters for Quindocqua. To assess the importance of replication within soils, coefficients of variation (CV) for leachate depth were calculated for different replicate numbers. A Monte Carlo simulation approach was used to repeatedly sample a subset of soil core lysimeters (N = 3) from the total number of replicates within each soil group (10 for Evesboro, Bojac, Sassafras; 5 for the Quindocqua).

<table border="0" cellpadding="0" cellspacing="0" width="1016">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Schedule 80 PVC Pipe</td>
			<td style="width:181px;">Fry&#39;s Plastic</td>
			<td style="width:119px;">Call</td>
			<td style="width:455px;">Sold in 10 ft lengths</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Fernco Fittings</td>
			<td style="width:181px;">Fry&#39;s Plastic</td>
			<td style="width:119px;">Call</td>
			<td>12 in. diameter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Type II PVC plates for perforated discs</td>
			<td style="width:181px;">AIN Plastic</td>
			<td style="width:119px;">Call</td>
			<td>Sold in 4&#39; x 8&#39; sheets of PVC II Vintec II&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Schedule 40 PVC Caps</td>
			<td style="width:181px;">Fry&#39;s Plastic</td>
			<td style="width:119px;">Call</td>
			<td>12 in. diameter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Stainless Steel Screws</td>
			<td style="width:181px;">Fastenal</td>
			<td style="width:119px;">135716</td>
			<td>#8 Bugle Head Phillips Drive Sharp Point Grade 18-8 Stainless Steel</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Silicone II Caulk</td>
			<td style="width:181px;">Lowe&#39;s</td>
			<td style="width:119px;">447488&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Nylon Tube Fitting</td>
			<td style="width:181px;">United State&#39;s Plastic Corp.</td>
			<td>61137</td>
			<td>0.5 in. NPT</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Foodgrade Tubing</td>
			<td style="width:181px;">Lowe&#39;s</td>
			<td>443209</td>
			<td>0.5 in. vinyl</td>
		</tr>
	</tbody>
</table>

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).

Soil moisture, leachate depth and leachate chemistry all illustrate variability across soils, revealing differences as a function of soil properties despite internal variability between replicate soil core lysimeters of a particular soil. The later point warrants particular note from the standpoint of experimental design, as inherent variability in soil moisture and leaching processes requires considerable replication to minimize type 2 statistical error. In the current study, coefficient...

Watch this Scientific Journal Video about A Protocol for Collecting and Constructing Soil Core Lysimeters at JoVE.com

A Protocol for Collecting and Constructing Soil Core Lysimeters

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.

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

The overall goal of this procedure is to demonstrate the collection, assembly, and irrigation of an intact soil core lysimeter to study nitrogen leaching through undisturbed agricultural soils. This method is designed to answer questions concerning nutrients and other chemicals that can leach below the root zone to shallow ground water. The main advantage of this technique is that it is quick and easy.We have found that we need four or five replicates to produce significant results. Although in this video we were looking at nitrate leaching, the method can be used to study many other compounds, such as phosphorus, pharmaceuticals, hormones, or metals such as arsenic. To begin, remove surface vegitation, rocks and other debris from the collection area.Position two lysimeter bodies on level ground where lysimeters are to be taken. Ensure that lysimeters are level, so that soil within the column is of a uniform depth. Drive a specially designed, trailer-mounted drop hammer into place over the lysimeter bodies.When the drop hammer is in place, deploy hydraulically powered outriggers to level the steel plate with the ground and the top of the lysimeter bodies. The outriggers also provide stability for the drop hammer. Partially hoist the steel plate weighing 1, 180 kilograms up a 3-meter tower with the aid of a mechanical winch.Release the steel plate to hammer to columns into the soil. Repeat this step several times, until the column rim is 2 cm above the soil surface. Check for soil compaction inside the lysimeter by measuring the depth of the soil inside and outside of the column.If the soil inside the column is more than 1 cm lower than the soil outside the column, soils are compacted, and are not suitable for research. Place a plywood disc inside the rim of the column to prevent contamination. Dig a trench beside the soil core and slightly deeper than the column bottom with a backhoe.Widen the hole with a shovel or pick, and expose as much of the outside of the cylinder as possible. Push a heavy metal digging bar down along the entire length of the side of the column, so that it is between the soil and the outside column wall. Pry the digging bar back and forth until the soil interface at the bottom of the column is broken, and slide the column into the center of the trench.Frame the lifting scissors around the top of the lysimeter in preparation for soil core removal. With a person holding each bar, pull up until the scissors close tightly around the column, and lift the lysimeter out of the hole. Place the lysimeter on a flat working surface, such as a flat board.After flipping the soil core over so that the bottom side is up, gently level the soil even with the rim of the PVC with a straight edge. Remove stones protruding above the plane of the rim with a pen knife or a screwdriver. Also loosen the soil and expose the natural surface textures therein.Fill any voids with chemically inert play sand and gently pack it. Grade the sand even with the column bottom with a straight edge, and remove any excess sand. Next, extrude a continuous round bead of clear silicone caulk around the rim of the lysimeter.The caulk should be thick enough to seal the perforated disk bottom to the lysimeter's, and prevent leaking. Lay the perforated disk onto the rim, with the filter fabric facing the sand, and press down firmly to allow good contact of the plate and lysimeter. Then drill eight evenly spaced pilot holes around the edge of the plate, and fasten the perforated disk with 1-inch stainless steel screws and a drill driver.Slip the flexible pipe coupling onto the lysimeter base, so that about 2 cm of the coupling are projecting above the lysimeter rim. Fit the modified PVC cap into the flexible pipe coupling, and push the cap down until it makes contact with the lysimeter body. Then place the fastening bands in the grooves of the coupling and lightly secure without constricting the coupling.Tighten the metal bands with a handheld hex driver until the lysimeter cap is held firmly in place. The lysimeter is ready to be flipped, and transported to a climate controlled facility. To install moisture sensors, first scribe a 5 cm long horizontal line on the lysimeter wall at 5 and 25 cm depths.Measure from the soil surface, and not the rim of the lysimeter. Drill a 1 cm diameter hole through the wall of the lysimeter at each end of the marked lines. Cut the remaining 3 cm of plastic between the drilled holes away with a rotary cutting tool.Next, chisel a 1-cm thick by 5-cm long slit into the soil to accommodate the casing of a moisture sensor. Push the moisture sensor into the hole, into the cleaned out slot, until the sensor prongs are firmly buried in the soil and only the wire is sticking out of the lysimeter. Clean the soil from the walls of the slot with a brush or rag.Apply a thick bead of silicone caulk into the slot to prevent water from leaking out. After the caulk has dried, apply a second cycle of silicone to ensure that all gaps in the hole surrounding the sensor are sealed. Seal gaps between the soil and the lysimeter wall with caulk to reduce the risk of preferential flow down the inside walls of the lysimeter.First, pierce and load a tube of clear silicone caulk into a standard caulk gun. Place the tip of the caulk tube between the void in the soil to be filled and the inside face of the lysimeter body. Then push the tip of the caulk gun below the soil about 2 cm.Squeeze the caulk out of the tube until it fills the void and oozes above the soil surface. After checking that the soil core is level as described in the text protocol, wrap Teflon tape around the threaded nylon tube fitting, and turn the fitting clockwise into the cap. Tighten the fitting with an adjustable wrench until none of the threads are visible.Push a 0.5-inch hose onto the barbed end of the nylon fitting, and cut the hose so that it passes approximately 4 cm into the mouth of the collection jug. Set the container under the lysimeter, and place the hose inside the collection jug. Cover the soil surface with cheesecloth, or another chemically inert mesh such as a window screen, to protect and preserve soil aggregates and surface residue.Measure 1, 450 ml of simulated rain water into a graduated cylinder, and pour it into a watering can equipped with a shower head. Gently and evenly sprinkle the water over the window screen at a rate that does not disturb the soil surface. After waiting a period of time for the water to infiltrate and percolate through the soil column into the cap and collection container, tip the lysimeter in toward the outlet hole until all water is drained from the lysimeter reservoir cap into the collection vessel.Measure the mass of leachate collected with a scale, and convert mass in grams to milliliters. Pour the leachate sample into a 350 ml sterile plastic sample bottle. Immediately filter 50 ml with a suction funnel equipped with 0.45 micron filter paper in preparation for nitrate analysis using color imagery via flow injection analysis.Representative results of the irrigation and leaching experiments are shown here. Average weekly leachate depths ranged from 1.12 to 1.95 cm for the four soils. Leachate recovery expresses percentage of irrigation water applied, followed a general trend related to soil texture, with recoveries from the sandy Evesboro and Sassafras soils being slightly more efficient than from the finer textured Bojac and Quindocqua soils.This figure shows that changes in soil water content at 5-cm and 25-cm depths, following irrigation, demonstrate differences in water transmission between coarser and finer textured soils. Moisture profiles indicate rapid movement of irrigation water through the coarser textured Evesboro sand and Sassafras sandy loam soils. This figure shows change in nitrate concentration before and after poultry litter application.Nitrate concentrations in leachate increased after litter application, but followed different temporal patterns between soils. Differences in leachate nitrate mass loss reflect not only trends in nitrate concentrations in leachate, but also differences in leachate depths. To assess the role of poultry litter application and leachate volume on nitrate flux, soil nitrate fluxes from before litter application were subtracted from subsequent weekly fluxes.While attempting this procedure, it is important to be safe. Always wear hearing protection while operating drills or the drop hammer. For safety, never work underneath the drop hammer.Be aware of other people in the area when you're operating the drop hammer, and maintain a safe distance from the drop hammer when operating. After watching this video you should have a good idea how to collect an intact soil core, construct a lysimeter, install soil moisture sensors, carry out irrigation, and collect leachate.

a-protocol-for-collecting-and-constructing-soil-core-lysimeters

Research

JoVE Journal

Environment

11.5K vistas.  USDA - Agricultural Research Service. The overall goal of this procedure is to demonstrate the collection, assembly, and irrigation of an intact soil core lysimeter to study nitrogen leaching through undisturbed agricultural soils. This method is designed to answer questions concerning nutrients and other chemicals that can leach below the root zone to shallow ground water. The main advantage of this technique is that it is quick and easy.We have found that we need four or five replicates to produce significant results. Al...