Table 7.
Soil microbial biomass nitrogen (MBN) (mg kg−1) in rubber and rubber–Flemingia macrophylla plantations from June 2015 to January 2017 (mean ± SD, n = 3).
| Soil depth (cm) | Treatments | Jun 2015 | Jan 2016 | Aug 2016 | Jan 2017 |
|---|---|---|---|---|---|
| 0–10 cm | R1 | 18.2 ± 1.3d | 35.2 ± 14.1b | 21.2 ± 3.2c | 20.5 ± 4.6cd |
| RF1 | 28.8 ± 4.6bc | 42.5 ± 11.9ab | 44.1 ± 10.5b | 32.5 ± 5.4ab | |
| R2 | 24.0 ± 4.8c | 54.7 ± 10.2a | 38.6 ± 3.9b | 34.0 ± 1.4ab | |
| RF2 | 34.0 ± 3.2b | 55.2 ± 3.3a | 59.3 ± 7.1a | 36.1 ± 7.1a | |
| 10–30 cm | R1 | 5.3 ± 0.2e | 32.7 ± 3.4b | 17.1 ± 4.1c | 17.0 ± 6.2de |
| RF1 | 10.8 ± 3.3e | 36.6 ± 3.9b | 25.2 ± 1.7c | 12.3 ± 3.9e | |
| R2 | 30.4 ± 2.1b | 32.8 ± 5.9b | 49.4 ± 15.5ab | 27.1 ± 0.6bc | |
| RF2 | 37.1 ± 3.3a | 35.8 ± 6.4b | 45.8 ± 4.7b | 32.2 ± 0.6ab |
R1: rubber plantations established in 2006; R2: rubber plantations established in 1994; RF1: Flemingia macrophylla introduced to R1 in 2010; RF2: Flemingia macrophylla introduced to R2 in 2010. Values within a column followed by the same letter do not differ significantly at P ≤ 0.05.