The contribution of maize cropping in the Midwest USA to global warming: A regional estimate
Agricultural soils emit about 50% of the global flux of N2O attributable to human influence, mostly in response to nitrogen fertilizer use. Recent evidence that the relationship between N2O fluxes and N-fertilizer additions to cereal maize are non-linear provides an opportunity to estimate regional N2O fluxes based on estimates of N application rates rather than as a simple percentage of N inputs as used by the Intergovernmental Panel on Climate Change (IPCC). We combined a simple empirical model of N2O production with the SOCRATES soil carbon dynamics model to estimate N2O and other sources of Global Warming Potential (GWP) from cereal maize across 19,000 cropland polygons in the North Central Region (NCR) of the US over the period 1964-2005. Results indicate that the loading of greenhouse gases to the atmosphere from cereal maize production in the NCR was 1.7Â Gt CO2e, with an average 268Â t CO2e produced per tonne of grain. From 1970 until 2005, GHG emissions per unit product declined on average by 2.8Â t CO2eÂ ha-1Â annum-1, coinciding with a stabilisation in N application rate and consistent increases in grain yield from the mid-1970's. Nitrous oxide production from N fertilizer inputs represented 59% of these emissions, soil C decline (0-30Â cm) represented 11% of total emissions, with the remaining 30% (517Â Mt) from the combustion of fuel associated with farm operations. Of the 126Â Mt of N fertilizer applied to cereal maize from 1964 to 2005, we estimate that 2.2Â Mt N was emitted as N2O when using a non-linear response model, equivalent to 1.75% of the applied N.
If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- G. Robertson & Peter Grace, 2004. "Greenhouse Gas Fluxes in Tropical and Temperate Agriculture: The need for a Full-Cost accounting of Global Warming Potentials," Environment, Development and Sustainability: A Multidisciplinary Approach to the Theory and Practice of Sustainable Development, Springer, vol. 6(1), pages 51-63, March.
When requesting a correction, please mention this item's handle: RePEc:eee:agisys:v:104:y:2011:i:3:p:292-296. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Shamier, Wendy)
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If references are entirely missing, you can add them using this form.
If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.
Please note that corrections may take a couple of weeks to filter through the various RePEc services.