Table 2.
Gross nitrification rates and the ratios of N2O production to nitrification in the studied agricultural soils.
| Land-use | Gross nitrification rate | Relative contribution % | N2Ocd | N2Odn | PN2O ‰e | |
|---|---|---|---|---|---|---|
| mg N kg−1 d−1 | Cad | Cbn | μg N2O-N cm−2 d−1 | |||
| Sugarcane | 1.70 (0.50) | 3.30 (0.45) | 96.67 (6.8) | 0.80 (0.03) | 23.40 (0.34) | 0.030 (0.0016) |
| Vegetable | 5.42 (0.43) | 76.36 (9.2) | 23.64 (3.91) | 53.65 (7.03) | 16.63 (3.30) | 0.024 (0.0011) |
| Dairy Pasture | 3.84 (0.78) | 29.09 (4.1) | 70.90 (4.97) | 20.24 (1.22) | 49.85 (8.34) | 0.033 (0.0026) |
| Cereal cropping | 9.88 (2.30) | 28.74 (8.6) | 71.26 (1.82) | 134.34 (4.06) | 334.47 (6.63) | 0.260 (0.0189) |
a
The relative contribution by denitrification (Cd) to N2O production.
b
The relative contribution by nitrification (Cn) to N2O production.
c
N2O production from nitrification (N2On).
d
N2O production from denitrification (N2Od).
e
The proportion of nitrified N emitted as N2O (PN2O).
Values in bracket are standard deviations.