Table 4.
Nitrous oxide emission factor (EF) and emission intensity (EI) (mean ± standard deviation) of the top-dressed N fertilization during two maize harvest seasons (2016/17 and 2017/18), as affected by the combination of N fertilization (0 or 150 kg ha-1) and intercrop with B. brizantha (B) or B. humidicola (H).
| Treatments | EF |
EI |
||
|---|---|---|---|---|
| 2016/17 | 2017/18 | 2016/17 | 2017/18 | |
| ------- % ------- | --- kg CO2 eq. t-1 of grain --- | |||
| M0 | – | – | 14.5a ± 2.49 | 21.0c ± 6.28 |
| MB0 | – | – | 11.9a ± 1.32 | 51.1a ± 18.1 |
| MH0 | – | – | – | 25.0c ± 8.22 |
| M150 | 0.06 | 0.22 | 13.11a ± 3.38 | 24.1c ± 13.9 |
| MB150 | 0.07 | 0.18 | 12.17a ± 2.60 | 36.6b ± 9.64 |
| MH150 | – | 0.23 | – | 21.0c ± 3. 43 |
M: maize monocrop; MB and MH: maize intercropped with B. brizantha and B. humidicola, respectively; 0 and 150 subscripts indicate the 0 and 150 kg ha-1 of N applied to the maize crop. Different letters after means denote significant differences between treatments in the columns for the LSD test (p ≤ 0.05).