GHGMP Feature Articles

Test kits to measure soil impact on GHG changes

New tools helps measure the greenhouse gas difference

Test kit

Agriculture researchers, agronomists and other extension specialists now have access to relatively simple tools that will make it easier to measure changes in greenhouse gas emissions brought about by improved crop and livestock management practices.

Being able to measure and quantify changes in gas emissions will provide tangible evidence to the frontline forces that improved production practices do make a difference.

One of the four types of monitoring kits being worked on by a Nova Scotia researcher is a Soil Greenhouse Gas Monitoring Kit, that can be used to properly collect gas samples in the field for later analysis in the lab.

The kit can be used by a trained technician, for example, to collect gas samples to measure how much carbon dioxide, methane or nitrous oxide - three common greenhouse gases - is released after various demonstration treatments.

"The value is that people involved in research and demonstration projects will be able to collect gas samples as the work is being done," says Dr. David Burton, research chair in climate change at the Nova Scotia Agricultural College in Truro. "Now we will not only be able to say a certain practice makes a difference in greenhouse gas emissions, we will be able to quantify it."

The kits are being developed in a collaborative effort between Burton and Dr. David Lobb, Associate Professor, Department of Soil Science, University of Manitoba.

Four kits

The four kits in this project include the greenhouse gas monitoring kit, a Soil Quality Monitoring Kit, which was actually developed by the U.S. Department of Agriculture (USDA), a Soil Environment Monitoring Kit, with components similar to a weather station, and a Soil Carbon Monitoring Kit. The gas monitoring kit, the soil quality kit, and the environment monitoring kit are completed and ready for use. Burton hopes to have the carbon monitoring kit ready later this year.

Test kit in use

The field test kits are being developed as part of the federal Greenhouse Gas Mitigation Program (GHGMP) for Canadian Agriculture. It's a national program designed to demonstrate a wide range of good production practices, through hundreds of on-farm demonstration projects in different agricultural sectors, all aimed at reducing greenhouse gas emissions.

With all these demonstrations being done, it was felt it would be beneficial to have the tools available to make a range of measurements.

The $91,500 project received funds from the GHGMP beef sector, which is administered by the Canadian Cattlemen's Association, the GHGMP soil and nutrient management sector, administered by the Soil Conservation Council of Canada, and the Agriculture and Agri-Food Canada Scientific Working Group associated with the program.

"We know different management practices will reduce the level of greenhouse gas emissions, but it is important to be able to measure those differences," says Burton. "Our goal was to develop reliable monitoring kits that can be used by demonstration coordinators or soil conservation staff in the field."

The idea is to simplify the testing process. "We're talking about kits that fit in a tool box and are carried out to the field," he says. "The kits have either the components to produce test results right in the field, or at least enable the technician to collect proper samples for analysis." And you don't have to be a researcher to use the kits either, adds Burton. "They are designed so anyone with training in agricultural science can follow the procedure."

The soils kit

The USDA-designed Soil Quality Monitoring Kit is being recommended for use in Canada, rather than reinvent the wheel here, says Burton.

"The USDA has developed a useful tool box kit that can be used to measure soil quality features right in the field," he says. "It's a good system. So we're advising people to check out the USDA Web site to either buy or build their own kits." The kit includes tests to measure soil respiration, water infiltration rate, soil pH, soil nitrate, electrical conductivity (salt concentration), earthworm activity, and tests for other soil characteristics.

Details on the USDA-designed kit can be found on the Internet at: www.soils.usda.gov/sqi/soil_quality/assessment/kit2.html.

With the USDA soils kit in mind, Burton and colleagues launched the project to develop similar field kits to be used to measure greenhouse gas emissions and other soil quality characteristics.

The GHG kit

The Soil Greenhouse Gas Monitoring Kit, developed over 2003 and 2004, has been tested at four sites across Canada. Several of the mobile kits are in the hands of GHGMP project co-ordinators in Alberta, Manitoba, New Brunswick, P.E.I. and Nova Scotia for use during the 2005 field season.

The information obtained from the kits will answer some of the key questions about how effective management changes are in reducing greenhouse gas emissions, says Burton. A complete gas analysis cannot be made in the field, but with proper samples and support information being collected in the field and sent to university-based testing labs, reports can be generated in short order.

With basic training a field technician can collect gas samples to be analyzed for carbon dioxide, nitrous oxide and methane gas levels. All three are greenhouse gases produced by activities in soils, and thus are impacted by farming practices.

Carbon dioxide is released through the burning of fossil fuels such as gasoline, and through tillage, which releases carbon sequestered in the soil to the atmosphere. Methane is released as a result of anaerobic fermentation, such as occurs in the rumen of cattle and in liquid manure storage systems. Small amounts of methane are continuously being consumed by the soil. Nitrous oxide is released primarily from soils after nitrogen fertilizer application, though some is also released from manure and fossil fuel burning.

"Our goal is to keep the testing simple," says Burton. "A person can take the kit out to a field, collect gas samples every 10 minutes for half an hour and send those samples to a lab for analysis." Several Canadian universities, as well as some private labs, have the capability to complete the analysis and produce a report within a couple of weeks.

The kits include the chambers needed for collecting samples, as well as tools for collecting other readings, such as soil moisture and soil temperature. Computer spreadsheets and presentations are also being developed to assist in the data analysis and interpretation.

"These kits are designed to measure treatment effects," says Burton, noting they are not as extensive as testing involved in research projects. "We want to measure the difference between no-till and conventional tillage, or the difference between different manure application rates and techniques. We're looking for a comparison of two different management approaches, so we need an analysis that shows which treatment is resulting in more greenhouse gas production."

Carbon kit

The Soil Carbon Monitoring Kit should be ready by the fall of 2005. This kit will make it possible to get a reading on soil organic matter right in the field. The level of organic matter directly relates to the amount of stored carbon.

"Initially we thought about making a kit to collect samples that could be sent for analysis," says Burton. "But in discussions with a number of people across the country, it was felt that some type of field test for organic matter was preferred."

While a reliable field testing method is available, Burton hopes to develop a different process that doesn't rely on toxic chemicals. "We have a test in mind that would use a common, safe, drugstore product, but we have to do more field testing to get the process right," he says. "However, I am quite confident we'll be able to make this work.

"This will be a neat process," he adds. "People will be able to take it with them on a demonstration field day, for example, and complete the test for soil organic matter right there in the field."

The kits will be tested over the next few years to ensure they produce accurate, reliable results and are user friendly.