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Submitted to: Soil Science Society of America Journal
Publication Type: Book / Chapter Publication Acceptance Date: 7/24/2016 Publication Date: 11/23/2016 Citation: Sainju, U.M. 2016. Net global warming potential and greenhouse gas intensity. In: Black, C.A., editor. Methods of Soil Analysis. Vol. 1. Madison, WI: Soil Science Society of America. p. 1-9. doi:10.2136/methods-soil.2015.0036. Interpretive Summary: Methods for measuring net global warming potential (GWP) and greenhouse gas intensity (GHG) account for all sources and sinks of GHG emissions are lacking. Sources of GHG include CO2, N2O, and CH4 emissions and CO2 emissions associated with farm operations, N fertilization, and other chemical inputs. Sinks of GHG include soil C sequestration and crop residue returned to the soil. This book chapter discusses methods of measuring net GWP and GHGI using two methods: In the soil organic C (SOC) method, GWP and GHGI are calculated by using N2O and CH4 emissions as well as CO2 emissions from farm operations, N fertilization, and other chemical inputs as GHG sources and C sequestration rate ('SOC) as GHG sink. In the soil respiration method, soil respiration (excluding root respiration) is included as another GHG source and previous year’s crop residue returned to the soil instead of 'SOC as GHG sink in addition to the above parameters. Advantages and drawbacks of each method of measuring GWP and GHGI are also discussed. This chapter will serve as an important tool for measuring GWP and GHGI in agroecosystems. Scientists, students, environmentalists, and other interested parties will benefit for using this method to measure net GHG emissions from agroecosystems which is a significant contributor of global GHG emissions. Technical Abstract: Various methods exist to calculate global warming potential (GWP) and greenhouse gas intensity (GHG) as measures of net greenhouse gas (GHG) emissions from agroecosystems. Little is, however, known about net GWP and GHGI that account for all sources and sinks of GHG emissions. Sources of GHG include CO2, N2O, and CH4 emissions and CO2 emissions associated with farm operations, N fertilization, and other chemical inputs. Sinks of GHG include soil C sequestration and crop residue returned to the soil. This chapter discusses methods of measuring net GWP and GHGI using two methods: In the soil organic C (SOC) method, GWP and GHGI are calculated by using N2O and CH4 emissions as well as CO2 emissions from farm operations, N fertilization, and other chemical inputs as GHG sources and C sequestration rate ('SOC) as GHG sink. In the soil respiration method, soil respiration (excluding root respiration) is included as another GHG source and previous year’s crop residue returned to the soil instead of 'SOC as GHG sink in addition to the above parameters. Advantages and drawbacks of each method of measuring GWP and GHGI are also discussed. |
