Name: continuous instream monitoring of nutrients and sediment in agricultural watersheds
Uploaded: 2017-09-26T13:00:00
Description: Watch this Scientific Journal Video about Continuous Instream Monitoring of Nutrients and Sediment in Agricultural Watersheds at JoVE.com

The research was possible due to funding from the Conservation Effects Assessment Project (CEAP). We are especially thankful for site-access permission from the producers, research assistance from members of the USDA-ARS-Delta Water Management Research Unit, and sample analysis by staff at the Ecotoxicology Research Facility, Arkansas State University. Part of this research was supported by an appointment to the ARS Participation Program, administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy and the USDA. ORISE is managed by ORAU under DOE contract number DE-AC05-06OR23100. All opinions expressed in this paper are the author&#39;s and do not necessarily reflect the policies and views of USDA, ARS, DOE, or ORAU/ORISE.

1. Site Selection
<ol>
	<li>Watershed selection
	<ol>
		<li>Select watershed(s) based on the magnitude of the pollution problem, priority of the watershed, proximity to the research facility, access to the site, and data objectives.</li>
	</ol>
	</li>
	<li>Stream sampling locations
	<ol>
		<li>Select stream sampling location(s) based on the study purpose. 
		NOTE: Optimal sampling locations are well-mixed within a cross-section, safely and easily accessible, geophysically stable (...

<ol>
	<li>Pellerin, B. 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=Emerging+Tools+for+Continuous+Nutrient+Monitoring+Networks:+Sensors+Advancing+Science+and+Water+Resources+Protection.">Emerging Tools for Continuous Nutrient Monitoring Networks: Sensors Advancing Science and Water Resources Protection.</a> J Am Water Resour Assoc. 52 (4), 993-1008 (2016).</li><li>Rozemeijer, 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=Application+and+Evaluation+of+a+New+Passive+Sampler+for+Measuring+Average+Solute+Concentrations+in+a+Catchment+Scale+Water+Quality+Monitoring+Study.">Application and Evaluation of a New Passive Sampler for Measuring Average Solute Concentrations in a Catchment Scale Water Quality Monitoring Study.</a> Environ Sci Tech. 44 (4), 1353-1359 (2010).</li><li>Cassidy, R., Jordan, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limitations+of+instantaneous+water+quality+sampling+in+surface-water+catchments:+Comparison+with+near-continuous+phosphorus+time-series+data.">Limitations of instantaneous water quality sampling in surface-water catchments: Comparison with near-continuous phosphorus time-series data.</a> J. Hydrol. 405 (1-2), 182-193 (2011).</li><li>Facchi, A., Gandolfi, C., Whelan, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+river+water+quality+sampling+methodologies+under+highly+variable+load+conditions.">A comparison of river water quality sampling methodologies under highly variable load conditions.</a> Chemosphere. 66 (4), 746-756 (2007).</li><li>Hamilton, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Global hydrological monitoring industry trends. , (2012).</li><li>Aryal, N., Reba, 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=Transport+and+transformation+of+nutrients+and+sediment+in+two+agricultural+watersheds+in+Northeast+Arkansas.">Transport and transformation of nutrients and sediment in two agricultural watersheds in Northeast Arkansas.</a> Agric Ecosyst Environ. 236, 30-42 (2017).</li><li>National Research Council (U.S.). <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Confronting the nation's water problems: The role of research. , (2004).</li><li>LMRRA (Lower Mississippi River Resource Assessment). <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Final Assessment in Response to Section 402 of WRDA 2000 Public Review Draft. , (2015).</li><li>MWNTF (Mississippi River/Gulf of Mexico Watershed Nutrient Task Force). <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> New Goal Framework. , (2008).</li><li>Reba, M. 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=A+statewide+network+for+monitoring+agricultural+water+quality+and+water+quantity+in+Arkansas.">A statewide network for monitoring agricultural water quality and water quantity in Arkansas.</a> J. Soil Water Conserv. 68 (2), 45a-49a (2013).</li><li>Duncan, D., Harvey, F., Walker, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Australian Water Quality Centre. , (2007).</li><li>Hamilton, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The 5 essential elements of a hydrological monitoring program. , (2012).</li><li>Wagner, R. J., Boulger, R. W., Oblinger, C. J., Smith, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> , (2006).</li><li>World Metorological Organization. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Manual on Stream Gauging Volume I-Fieldwork. , (2010).</li><li>American Public Health Association, American Water Works Association, &amp; Water Environment Federation. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Standard methods for the examination of water &amp; wastewater. , (2005).</li><li>ASTM (American Society of Testing and Materials) D3977-97. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Standard test methods for determining sediment concentration in water samples. , (1997).</li><li>O'Connor, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+temporal+and+spatial+distribution+of+dissolved+oxygen+in+streams.">The temporal and spatial distribution of dissolved oxygen in streams.</a> Water Resour Res. 3 (1), 65-79 (1967).</li><li>Dabney, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cover+crop+impacts+on+watershed+hydrology.">Cover crop impacts on watershed hydrology.</a> J Soil Water Conserv. 53 (3), 207-213 (1998).</li><li>Udawatta, R. P., Motavalli, P. P., Garrett, H. E., Krstansky, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nitrogen+losses+in+runoff+from+three+adjacent+agricultural+watersheds+with+claypan+soils.">Nitrogen losses in runoff from three adjacent agricultural watersheds with claypan soils.</a> Agric Ecosyst Environ. 117 (1), 39-48 (2006).</li></ol>

Overall, the continuous monitoring of nutrients and sediment has several advantages over monitoring using the grab sampling method. Hydrological and water quality processes are affected by rainfall over a very short span of time. Users can obtain high temporal-resolution data on nutrients and sediment to study complex problems. Other water quality parameters, such as conductivity, pH, temperature, and DO, can be obtained simultaneously and at the same cost as for monitoring nitrate, ammonium, and turbidity. Moreover, the...

Water quality monitoring provides information on the concentrations of pollutants at different spatial scales, depending upon the size of the contributing area, which can range from a plot or a field to a watershed. This monitoring takes place over a period of time, such as a single event, a day, a season, or a year. The information garnered from monitoring water quality, mainly relating to nutrients (e.g., nitrogen and phosphorus) and sediment, can be used to: 1) understand hydrological processes and the transport and transformation of pollutants in streams, such as agricultural drainage ditches; 2) evaluate the efficiency of management practices applied to the watershed to reduce the nutrient and sediment load and to increase the water quality; 3) assess the delivery of the sediment and nutrients to the water downstream; and 4) improve the modeling of nutrients and sediment to understand the hydrological and water quality processes that determine pollutant transport and dynamics over the range of temporal and spatial scales.
This information is crucial to aquatic ecosystem restoration, sustainable planning, and the management of water resources1.
The most commonly used method for nutrient and sediment monitoring in a watershed is grab sampling. Grab sampling accurately represents a snapshot concentration at the time of sampling2. It can also depict a variation of pollutant concentrations with time if frequent sampling is done. However, frequent sampling is time intensive and expensive, often making it impractical2. Additionally, grab sampling may under- or overestimate the actual pollutant concentrations outside of the sampling time2,3,4. Consequently, loads calculated using such concentrations may not be accurate.
Alternatively, continuous monitoring provides accurate and timely information on water quality in a predetermined time interval, such as a minute, an hour, or a day. Users can select the appropriate time intervals based on their needs. Continuous monitoring enables the researchers, planners, and managers to optimize sample collection; develop and monitor time-integrated metrics, such as total maximum daily loads (TMDLs); evaluate the recreational use of the water body; assess baseline stream conditions; and spatially and temporally evaluate the variation of pollutants to determine cause-effect relationships and develop a management plan5,6. Continuous monitoring of nutrients and sediment has recently received increased attention due to advances in computing and sensor technology, the improved capacity of storage devices, and the increasing data requirements needed to study more complex processes1,5,7. In a global survey of over 700 water professionals, the use of multi-parameter sondes increased from 26% to 61% from 2002 to 2012 and is expected to reach 66% by 20225. In the same survey, 72% of respondents indicated the need for the expansion of their monitoring network to meet their data needs5. The number of stations in a monitoring network and the number of variables monitored per station in 2012 are expected to increase by 53% and 64%, respectively, by 20225.
However, continuous water quality and quantity monitoring in agricultural watersheds is challenging. Large rainfall events wash away sediment and macrophytes, contributing to high sediment load and debris buildup in the sensors and sondes. The runoff of excess nitrogen and phosphorus applied to agricultural fields creates ideal conditions for the growth of microscopic and macroscopic organisms and for the fouling of instream sensors and sondes, especially during the summer. Fouling and sediment buildup can cause sensors to fail, drift, and produce unreliable data. Despite these challenges, finer temporal resolution (as low as per minute) data are required to study the runoff processes and non-point source contamination, as they are affected by watershed characteristics (e.g., size, soil, slope, etc.) and the timing and intensity of rainfall7. Careful field observation, frequent calibration, and proper cleaning and maintenance can ensure good-quality data from the sensors and sondes, even at the finer time resolution.
Here, we discuss a method for the in situ continuous monitoring of two agricultural watersheds using multi-parameter water quality sondes, area-velocity and pressure transducer sensors, and autosamplers; their calibration and field maintenance; and data processing. The protocol demonstrates a way in which continuous water quality monitoring can be performed. The protocol is generally applicable to continuous water quality and quantity monitoring at any type or size of watershed.
The protocol was carried out in Northeast Arkansas in Little River Ditches Basin (HUC 080202040803, 53.4 km2 area) and Lower St. Francis Basin (HUC 080202030801, 23.4 km2 area). These two watersheds drain into tributaries of the Mississippi River. A need for monitoring tributaries of the Mississippi River was identified by the Lower Mississippi River Conservation Committee and the Gulf of Mexico Hypoxia Task Force to develop a watershed management plan and to record the progress of management activities8,9. Moreover, these watersheds are characterized as focus watersheds by the United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS), based on the potential for reducing nutrient and sediment pollution and for improving water quality10. Edge-of-field monitoring is being carried out in these watersheds as part of the statewide Mississippi River Basin Healthy Watershed Initiative (MRBI) network11. More details of the watersheds (i.e., site locations, watershed characteristics, etc.) are provided in Aryal and Reba (2017)6. In short, the Little River Ditches Basin has predominantly silt loam soils, and cotton and soybean are the major crops, whereas the Lower St. Francis Basin has predominantly Sharkey clay soil, and rice and soybean are the major crops. At each watershed, in situ continuous water quantity and quality monitoring (i.e., discharge temperature, pH, DO, turbidity, conductivity, nitrate, and ammonium) was carried out at three stations in the mainstream using this protocol to understand the spatial and temporal variability in the pollutant loads and the hydrological processes. Additionally, weekly water samples were collected and analyzed for suspended sediment concentration.

<table border="0" cellpadding="0" cellspacing="0" width="812">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:149px;">Multiparameter sonde</td>
			<td style="width:109px;">Hach Hydrolab</td>
			<td style="width:135px;">DS5X</td>
			<td style="width:419px;">measures temperature, pH, conductivity, dissolved oxygen, nitrate, ammonium, turbidity</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:149px;">Area velocity flow module and sensor</td>
			<td style="width:109px;">Teledyne Isco</td>
			<td style="width:135px;">2150</td>
			<td style="width:419px;">measures average stream velocity and flow depth, and calculates flow rate and total flow based on provided cross-section area of the ditch. Stored data can be downloaded directly to computer.</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:149px;">Automatic portable water sampler</td>
			<td style="width:109px;">Teledyne Isco</td>
			<td style="width:135px;">ISCO 6712</td>
			<td style="width:419px;">automatically samples water in the set interval or in conjunction with flow module and sensor</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:149px;">Pressure Transducer</td>
			<td style="width:109px;">In-situ</td>
			<td style="width:135px;">Rugged Troll 100</td>
			<td style="width:419px;">measures presure, level and temperature in the water. Stored data can be directly downloaded to the computer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:149px;">Portable flow meter</td>
			<td style="width:109px;">Flo-mate (Hach)</td>
			<td style="width:135px;">Marsh-McBirney 2000</td>
			<td style="width:419px;">For manual discharge measurement</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:149px;">Battery, 12 v, rechargeable</td>
			<td style="width:109px;">UPG</td>
			<td style="width:135px;">UB 1270</td>
			<td style="width:419px;">To power sonde</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:149px;">Battery, 12 v, rechargeable</td>
			<td style="width:109px;">Interstate Batteries</td>
			<td style="width:135px;">SRM 27</td>
			<td style="width:419px;">Lead acid battery to power autosampler</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Solar panel</td>
			<td style="width:109px;">Alt E</td>
			<td style="width:135px;">ALT20-12P</td>
			<td style="width:419px;">To recharge battery at the site</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">C-8 batteries</td>
			<td style="width:109px;"></td>
			<td style="width:135px;"></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:149px;">Calibration standards</td>
			<td style="width:109px;">Hach or Fisher Scientific</td>
			<td style="width:135px;">mulitple</td>
			<td style="width:419px;">Standards of pH (4,7,10), conductivity (1412 uS/cm), nitrate (5 and 50 mg/L), ammonium (5 and 50 mg/L), and turbidity (50,100,200 NTU)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">High nitrate standard</td>
			<td style="width:109px;">Hach</td>
			<td style="width:135px;">013810HY</td>
			<td style="width:419px;">50 mg/L</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Low nitrate standard</td>
			<td style="width:109px;">Hach</td>
			<td style="width:135px;">013800HY</td>
			<td style="width:419px;">5 mg/L</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">High ammonium standard</td>
			<td style="width:109px;">Hach</td>
			<td style="width:135px;">002588HY</td>
			<td style="width:419px;">50 mg/L</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Low ammonium standard</td>
			<td style="width:109px;">Hach</td>
			<td style="width:135px;">002587HY</td>
			<td style="width:419px;">5 mg/L</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Turbidity standard</td>
			<td style="width:109px;">Fisher scientific</td>
			<td>R8819050-500G</td>
			<td style="width:419px;">50 NTU</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Turbidity standard</td>
			<td style="width:109px;">Fisher scientific</td>
			<td>88-061-6</td>
			<td style="width:419px;">100 NTU</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Turbidity standard</td>
			<td style="width:109px;">Fisher scientific</td>
			<td>R8819200500 C</td>
			<td style="width:419px;">200 NTU</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Potassium chloride salt pellets</td>
			<td style="width:109px;">Hach</td>
			<td style="width:135px;">005376HY</td>
			<td style="width:419px;">to maintain electrolyte for pH electrode</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Potassium chloride standard</td>
			<td style="width:109px;">Fisher scientific</td>
			<td style="width:135px;">5890-16</td>
			<td style="width:419px;">1412 us/cm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Buffer solution, pH 4</td>
			<td style="width:109px;">Fisher scientific</td>
			<td style="width:135px;">SB99-1</td>
			<td style="width:419px;">for pH sensor calibration</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Buffer solution, pH 7</td>
			<td style="width:109px;">Fisher scientific</td>
			<td style="width:135px;">SB108-1</td>
			<td style="width:419px;">for pH sensor calibration</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Buffer solution, pH 10</td>
			<td style="width:109px;">Fisher scientific</td>
			<td style="width:135px;">SB116-1</td>
			<td style="width:419px;">for pH sensor calibration</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Silicon sealant</td>
			<td style="width:109px;">Hach</td>
			<td style="width:135px;">00298HY</td>
			<td style="width:419px;">For sealing sensor battery cover water tight</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:149px;">All purpose cleaner</td>
			<td style="width:109px;">Sunshine Makers Inc</td>
			<td style="width:135px;">Simple green</td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Wipes</td>
			<td style="width:109px;">Kimberly-Clark</td>
			<td style="width:135px;"></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">L-bracket</td>
			<td style="width:109px;"></td>
			<td style="width:135px;"></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:149px;">Telsbar post</td>
			<td style="width:109px;">Unistrut Service Company</td>
			<td style="width:135px;"></td>
			<td style="width:419px;">Secure sensors and sondes in the stream</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Steel wire</td>
			<td style="width:109px;"></td>
			<td style="width:135px;"></td>
			<td style="width:419px;">supend sonde and PT sensor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Carabiner</td>
			<td style="width:109px;"></td>
			<td style="width:135px;"></td>
			<td style="width:419px;">supend sonde and PT sensor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Allen wrench</td>
			<td style="width:109px;"></td>
			<td style="width:135px;"></td>
			<td style="width:419px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:149px;">Copper wire mesh</td>
			<td style="width:109px;">Bird B Gone</td>
			<td style="width:135px;"></td>
			<td style="width:419px;">Rodent and bird control copper mesh roll</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:149px;">Adhesive Tape</td>
			<td style="width:109px;">Agri Drain Corporation</td>
			<td style="width:135px;"></td>
			<td style="width:419px;">Tile tape, works in wet and cold weather</td>
		</tr>
	</tbody>
</table>

continuous instream monitoring of nutrients and sediment in agricultural watersheds

Pollutant concentrations and loads in watersheds vary considerably with time and space. Accurate and timely information on the magnitude of pollutants in water resources is a prerequisite for understanding the drivers of the pollutant loads and for making informed water resource management decisions. The commonly used &#34;grab sampling&#34; method provides the concentrations of pollutants at the time of sampling (i.e., a snapshot concentration) and may under- or overpredict the pollutant concentrations and loads. Continuous monitoring of nutrients and sediment has recently received more attention due to advances in computing, sensing technology, and storage devices. This protocol demonstrates the use of sensors, sondes, and instrumentation to continuously monitor in situ nitrate, ammonium, turbidity, pH, conductivity, temperature, and dissolved oxygen (DO) and to calculate the loads from two streams (ditches) in two agricultural watersheds. With the proper calibration, maintenance, and operation of sensors and sondes, good water quality data can be obtained by overcoming challenging conditions such as fouling and debris buildup. The method can also be used in watersheds of various sizes and characterized by agricultural, forested, and/or urban land.

In the Aryal and Reba (2017) publication, this protocol was used to study the transport and transformation of nutrients and sediment in two small agricultural watersheds6. Additional outcomes from this protocol are described below.
Rainfall-runoff Water Quality Relationships:
The strength of continuous monitoring is that users can choose a fine tim...

Watch this Scientific Journal Video about Continuous Instream Monitoring of Nutrients and Sediment in Agricultural Watersheds at JoVE.com

Continuous Instream Monitoring of Nutrients and Sediment in Agricultural Watersheds

With the advancement of technology and the rise in end-user expectations, the need and use of higher temporal resolution data for pollutant load estimation has increased. This protocol describes a method for continuous in situ water quality monitoring to obtain higher temporal resolution data for informed water resource management decisions.

Pollutant concentrations and loads in watersheds vary considerably with time and space. Accurate and timely information on the magnitude of pollutants in ...

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Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. ...

The Hawaii Protocol for Scientific Monitoring of Coffee Berry Borer: a Model for Coffee Agroecosystems Worldwide

Coffee berry borer (CBB) is the most devastating insect pest for coffee crops worldwide. We developed a scientific monitoring protocol that is aimed at ...

The Plant Infection Test: Spray and Wound-Mediated Inoculation with the Plant Pathogen Magnaporthe Grisea

The Plant Infection Test: Spray and Wound-Mediated Inoculation with the Plant Pathogen Magnaporthe Grisea

Plants possess a powerful system to defend themselves against potential threats by pathogenic fungi. For agriculturally important plants, however, current ...

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Denitrification is the primary biogeochemical process removing reactive nitrogen from the biosphere. The quantitative evaluation of this process has ...