SOIL CARBON AND CLIMATE CHANGE NEWS
From Kansas State University's:
Consortium for Agricultural Soils Mitigation of Greenhouse Gases (CASMGS)
http://soilcarboncenter.k-state.edu
Charles W. Rice, K-State Department of Agronomy, National CASMGS Director
(785) 532-7217 cwrice@ksu.edu
Scott Staggenborg, K-State Department of Agronomy (785) 532-7214 sstaggen@ksu.edu
Steve Watson, CASMGS Communications (785) 532-7105 swatson@ksu.edu
November 10, 2011
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New Reports Explore Greenhouse Gas
Mitigation Opportunies in U.S. Agriculture
Two reports from the Technical Working Group on Agricultural Greenhouse Gases (T-AGG) were released in November 2011 that explore the spectrum of greenhouse gas (GHG) mitigation opportunities in agriculture in the U.S. The principal authors are Lydia P. Olander, with the Nicholas Institute at Duke University, and co-invesigator Alison J. Eagle.
T-AGG was formed to provide basic information on GHG mitigation opportunities in agriculture. The T-AGG assessment covers a wide range of agricultural practices for principal cropping systems in the United States. It provides a roadmap and resource for programs and initiatives that are designing protocols, metrics, or incentives to engage farmers and ranchers in large-scale efforts to enhance GHG mitigation on working agricultural land in the United States.
The T-AGG assessment identified 28 agricultural land management activities likely to be beneficial for GHG mitigation. Five have relatively high mitigation potential due to land use changes and are applicable in only some regions.
* Switch to short-rotation woody crops
* Convert cropland to pasture
* Setaside cropland or plant herbaceous buffers
* Replace annuals with perennial crops
* Restore wetlands
Fifteen tend to have lower mitigation potential, do not shift land use, and are applicable in many U.S. regions.
* Switch to no-tillage
* Switch to other conservation tillage
* Eliminate summer fallow
* Use winter cover crops
* Diversify annual crop rotations
* Incorporate perennials into crop rotations
* Reduce fertilizer N application rate by 15%
* Adjust rice water management to reduce CH4
* Manage species composition on grazing land
* Switch fertilizer N source from ammonium-based to urea
* Switch to slow-release fertilizer N source
* Change fertilizer N placement
* Change fertilizer N application time
* Use nitrification inhibitors
* Plant rice cultivars that produce less CH4
The remaining eight have significant data gaps and need additional research. These activities include increased cropping intensity, agroforestry, histosol management, and rotational grazing for soil C sequestration or conservation, as well as irrigation improvements and improved manure application for N2O emission reduction. Rotational grazing on pasture lands is particularly interesting. While the C sequestration potential from this practice seems positive, its broader impact on the efficiency of livestock production and the potential for broader mitigation effects is even more promising.
For 14 other activities, mitigation potential was uncertain, low, or negative. Six of these activities may deserve additional attention as they have been little studied or studies have yielded variable results. Seven of these activities have low or negative net GHG mitigation potential. The final activity, biochar application, may have significant potential, but research on the magnitude of this potential and on life-cycle implications is needed.
The two reports released in November are:
1. “Greenhouse Gas Mitigation Opportunities for Agricultural Land Management in the United States”
For complete details, see:
http://nicholasinstitute.duke.edu/ecosystem/t-agg
-- Steve Watson, CASMGS Communications
-- Steve Watson, CASMGS Communications