Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study finds crop performance matters when evaluating greenhouse gas emissions

06.09.2011
Measuring the emission of greenhouse gases from croplands should take into account the crops themselves.

That's the conclusion of a study in the Sept.-Oct. issue of the Journal of Environmental Quality, which examined the impact of farm practices such as tillage on the greenhouse gas, nitrous oxide. Expressing emissions per unit of crop yield rather than on a more conventional per area basis produced very different results, says the study's leader, Rod Venterea, research soil scientist with the United States Department of Agriculture's Agricultural Research Service.

In particular, his team found that total nitrous oxide emissions were not significantly affected by tillage practices when expressed on an area basis. When they were calculated per unit yield of grain, however, emissions were significantly greater under no-tillage compared with conventional tillage. A byproduct of many agricultural systems, nitrous oxide is a potent greenhouse gas (GHG) with a heat-trapping potential more than 300 times that of carbon dioxide.

The findings have important implications for how the greenhouse gases generated by agriculture are reported, evaluated, and potentially mitigated. Nitrous oxide emissions were slighter higher under no-till on a per area basis in the study, Venterea explains, but not high enough to differ statistically from those under conventional tillage. "But when we added in the fact that no-tillage also reduced yields, the effect of tillage did become significant," he says. "The point is that you need to look at both nitrous oxide emissions and yield together."

While previous studies have shown that practices like fertilizer and tillage management can affect nitrous oxide emissions, relatively few have reported the effects of these practices on crop performance at the same time. In addition, GHG emissions are commonly expressed with respect to area of field: for example, kilogram nitrous oxide emitted per hectare. Recent research has suggested that expressing GHG emissions per unit of yield may be more meaningful, although few studies have actually done that.

To see how yield-scaled calculations might change the picture on emissions, USDA-ARS researchers in collaboration with University of Minnesota colleagues measured the effects of tillage and nitrogen (N) fertilizer management on nitrous oxide emissions, grain yields, and crop N uptake over three consecutive growing seasons in Minnesota. The experiment was conducted in research plots used for corn and soybean production, which were maintained under either no-till or conventional tillage for 18 years.

When the scientists calculated nitrous oxide emissions per unit yield of grain or grain N, they found that emissions under no-tillage were 52 and 66% higher, respectively, than with conventional tillage. In other words, for this cropping system and climate, Venterea says, no-till practices would generate substantially more nitrous oxide than would conventional tillage for the same amount of grain. The effect was due to lower yields under no-till, combined with slightly greater area-scaled nitrous oxide emissions.

Reduced yields under continuous no-till management in parts of the upper Midwest and other regions have been attributed to lower soil temperatures in spring, which may inhibit plant development. In other geographic regions, though, no-till can actually increase yields.

"So, for these other regions, expressing GHG emissions on a yield-basis could reveal benefits to no-till management that otherwise might not be quantified," Venterea says.

The study was funded by the USDA National Institute for Food and Agriculture (NIFA) and the Foundation for Agronomic Research.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at https://www.agronomy.org/publications/jeq/abstracts/40/5/1521.

The Journal of Environmental Quality is a peer-reviewed, international journal of environmental quality in natural and agricultural ecosystems published six times a year by the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Soil Science Society of America (SSSA). The Journal of Environmental Quality covers various aspects of anthropogenic impacts on the environment, including terrestrial, atmospheric, and aquatic systems.

The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.

Sara Uttech | EurekAlert!
Further information:
http://www.agronomy.org

More articles from Agricultural and Forestry Science:

nachricht Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

nachricht New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>