1 Research on N 2 O Emissions from Agricultural Soils California Air Resources Board November 13, 2008

2 A Kyoto greenhouse gas (GHG) The Kyoto six: CO 2, CH 4, N 2 O, HFCs, PFCs, and SF 6 Global Warming Potential (GWP) 310 (IPCC, 2001); 298 (IPCC, 2007) Background concentration in the atmosphere ~275 ppbv in 1750, ~290 ppbv in 1950, currently ~310 ppbv Increases largely caused by increased nitrogen fertilizer use What is N 2 O

3 AB 32 Signed into law on September 27, 2006 Aggressive targets for reducing GHGs Early Action items 44 Early Action measures Measure 31: Collaborative Research to Understand How to Reduce GHG Emissions From Nitrogen Land Application Scoping Plan

4 California Greenhouse Gas Inventory California 2004 GHG Inventory (538 MMT CO 2 E) California N 2 O Inventory (15.4 MMTCO 2 E )

5 N 2 O Inventory Estimation Methods IPCC Tier 1 approach (Emission Factor, EF) Current California method for estimating agricultural soil N 2 O emissions N 2 O Emissions = Activity x EF = Soil N Inputs x EFs IPCC Tier 2 approach (disaggregated EFs) Considering site specific information IPCC Tier 3 approach: modeling/measurement 5

6 Summary of N 2 O Literature Data Y=0.01X Current CA default

7 Overview of N 2 O Research Nitrogen fertilizer management has been an important research topic Nitrogen fertilizer efficiency Leaching/runoff controls Limited data on N 2 O emissions Process models are more reliable for predicting emission trends, but less for predicting magnitude N processes in the field are highly variable

8 N 2 O Research Gaps Need California specific N 2 O emission data for baseline emissions inventory estimates Need to improve model applicability, validity, and reliability Criteria pollutants (NO x ) Indirect emissions, other sources

9 Planned Research Projects (08-09) Funding Agency CECCDFAARB Funding$500,000$150,000$300,000 Title N 2 O Emissions from the Application of Fertilizers in Agricultural Soils Measuring and Modeling Nitrous Oxide Emissions from California Cotton, Corn and Vegetable Cropping Systems Field Study of N 2 O Emissions from Selected California Cropping Systems Investigator Will Horwath (UCD), Johan Six (UCD), Dave Goorahoo (CSU Fresno), and Bill Salas (Applied Geosolutions) et al.

10 Stakeholder Involvement Coordinated through San Joaquin Valley Agricultural Technical Committee Three public workshops held Dates: May 21, September 9, and October 20, 2008 Attended by growers, researchers, fertilizer industry representatives, and state and local agencies Focus: N 2 O research priorities and technical issues Follow up meetings Further technical discussion on projects Kick off meeting Update meetings: quarterly progress reporting

11 Summary N 2 O is an important GHG Nitrogen fertilizer application is the major source of N 2 O emissions from agricultural soil management Research on baseline N 2 O emissions from nitrogen fertilizer use is underway in California Additional funding is needed to address criteria pollutants (NO x ) and other emission sources