Table 2.
Cereal yields (t ha−1) and estimated total annual (on-site) emissions of greenhouse gases (kg C-equivalent ha−1) from irrigated rice-wheat systems in the Indo-Gangetic Plain in terms of carbon equivalents (from Grace et al. 2003).
| treatments | no fertilizer | recommended fertilizer | recommended+ FYM |
|---|---|---|---|
| rice yield (t ha−1) | 3.74 | 5.67 | 6.41 |
| wheat yield (t ha−1) | 1.71 | 3.97 | 4.60 |
| conventional tillage and resides retained (kg C-equivalent ha−1) | 3496 | 4721 | 7137 |
| conventional tillage and residues burnt (kg C-equivalent ha−1) | 3953 | 5510 | 8032 |
| no tillage and residues retained (kg C-equivalent ha−1) | 2966 | 4362 | 6724 |
Carbon equivalent calculated based on CO2 released during all agricultural operations. A global warming potential of 21 and 310 was used for CH4 and N2O, respectively. FYM, farmyard manure.