Table 2 Details of coefficients used for the assessment of indirect nitrous oxide (N 2 O) emission
Primary factor | Break-up of primary factor | Details | Coefficient or value | Remark | |
|---|---|---|---|---|---|
IPCC emission factor | Indian emission factor | ||||
N2O(G) (N2O emission from volatilization of applied nitrogen fertilizer and animal manure and its subsequent atmospheric deposition as NOx and NH4) | NFERT | The total amount of synthetic fertilizer consumed annually [17] | -- | -- | -- |
The value of FracGASF, T, N(T), Nex(T), and FracGASMweresame as in Table 1. | -- | -- | -- | -- | |
EF4 [kg N2O-N kg-1 NH4-N and NOx-N deposited] | Emission factor for N2O emission from atmospheric NH3 and NOx | 0.01 [19] | 0.005 [8] | -- | |
N2O(L) (N2O produced from leaching and runoff of applied nitrogen fertilizer and animal manure) | NFERT | The total amount of synthetic fertilizer consumed annually [17] | -- | -- | -- |
The value of T, N(T), and Nex(T), are same as in table 1. | -- | -- | -- | -- | |
FracFUEL-AM | Animal manure burnt for fuel | 52.5% [22] | 52.5% [22] | IPCC manual suggests using official statistics of the nation or expert survey [19]. | |
FracPRP-AM | Fraction of animal manure that is deposited on to the soil by grazing animal | Not used in this study | Not used in this study | No data available. | |
FracCOLLEC | Loss during the collection of dung | 30.0% [23] | 30.0% [23] | -- | |
FracFEED-AM | Fraction of animal manure used as feed | 0.0% | 0.0% | Taken as zero, as animal manure is hardly used as feed in India [8]. | |
FracCONST-AM | Fraction of animal manure used in construction | 2.0% [22] | 2.0% [22] | IPCC manual suggestsuse of official statistics of the nation or expert survey [19]. | |
FracLEACH | Fraction of nitrogen lost through leaching | 30.0% [19] | 10.0% [8] | IPCC manual uses default value of 30%for FracLEACH. This default value was largely based on mass balance studies comparing agricultural N inputs to N recovered in rivers. The IPCC manualsuggests the N that is deposited away from agricultural land, a lower value of FracLEACH may be more appropriate based on regional or national studies [19]. Bhatia et al. [8] used an Indian emission factor of 10% based on the studies by Singh et al. [30] and Patel et al. [31]. | |
EF5 [kg N2O-N kg-1leached and run off] | The emission factor for depositing N from leaching and run-off. | 0.025 [19] | 0.005 [8] | -- | |