Table S1 Main equations and default values used to calculate GHG emissions

Emission inventory* / Method / Equation / Default value
Annual change in organic carbon stocks in mineral soils / Tier 2 / Equation 2.25 / D = 1 year; calculation to the depth of 40 cm;
Enteric fermentation emissions from a livestock category / Tier 2 / Equations 10.21, 10.3, 10.4, 10.6, 10.14, 10.15, and 10.16 / Ym= 6.5%; Cfi = 0.370; Ca = 0; C = 1.0; DE% = 55%;
CH4 emissions from manure management / Tier 2 / Equations 10.22, 10.23, and 10.24 / Bo = 0.1; MCF = 0.5%;
N2O emissions from manure management / Tier 2 / Equation 10.25 for direct emissions;
10.26, 10.27, 10.28, and 10.29 for indirect emissions; / EF3 = 0.01; FracGasMS = 45%; EF4 = 0.01; FracleachMS = 5%; EF5 = 0.0075;
N2O emissions from managed soils / Tier 2 / Equation 11.1 for direct emissions;
11.8 for nitrogen mineralized in mineral soils;
11.9, and 11.10 for indirect emissions; / EF1 = 0.01; EF4 = 0.01; EF5 = 0.0075; FracGASM = 0.2; FracLEACH-(H) = 0.3;
CO2 emissions from urea production / Tier 2 / Equation 3.3 / TFR (GJ(NCV)/tNH3) = 37.5%; CCF (kg/GJ) = 15.3;
COF (ts CO2/tNH3) = 2.104;
CO2 emissions from urea fertilization / Tier 1 / Equation 11.13 / EF (t of C/t of urea) = 0.20

*All calculations of GHG emissions from the agro-ecosystem were made according to the 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories.

Note: Cfi = a coefficient which varies for each animal category; Ca = a coefficient corresponding to animal’s feeding situation; DE% = digestible energy expressed as a percentage of gross energy; Ym = methane conversion factor, percentage of gross energy in feed converted to methane; C = a coefficient with a value of 0.8 for females, 1.0 for castrates, and 1.2 for bulls; Bo = methane-producing capacity of the manure; MCF = default methane conversion factor; EF3 = emission factor for direct N2O emissions from manure management system; FracGasMS = percent of managed manure nitrogen for livestock category T that volatilizes as NH3 and NOxin the manure management system S; EF4 = emission factor for N2O emissions from atmospheric deposition of nitrogen on soils and watersurfaces; FracleachMS = percent of managed manure nitrogen losses for livestock category T due to runoff andleaching during solid and liquid storage of manure; EF5 = emission factor for N2O emissions from nitrogen leaching and runoff; EF1 = emission factor for N2O emissions from nitrogen inputs； FracGASM = fraction of applied organic nitrogen fertilizer materials (FON) and of urine and dung nitrogen deposited bygrazing animals (FPRP) that volatilizes as NH3 and NOx, kg N volatilized； FracLEACH-(H) = fraction of all nitrogen added tomineralized in managed soils in regions where leaching/runoffoccurs that is lost through leaching and runoff；TFR = total fuel requirement for fuel type; COF = carbon oxidation factor of the fuel type; CCF = carbon content factor of the fuel type; EF = emission factor.

????et al.Chinese Science Bulletin | Jan??? 2009 | vol. 54 | no. ? | ?-? 1