Table 6.

Light fraction organic nitrogen (LFON) (g 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	0.057 ± 0.010b	0.051 ± 0.010b	0.049 ± 0.012c	0.044 ± 0.003b
	RF1	0.062 ± 0.009b	0.070 ± 0.014a	0.117 ± 0.016a	0.068 ± 0.005a
	R2	0.077 ± 0.013a	0.085 ± 0.014a	0.077 ± 0.009b	0.068 ± 0.013a
	RF2	0.078 ± 0.005a	0.069 ± 0.003a	0.077 ± 0.005b	0.051 ± 0.004b
10–30 cm	R1	0.016 ± 0.003c	0.011 ± 0.002c	0.020 ± 0.004d	0.020 ± 0.003c
	RF1	0.021 ± 0.005c	0.019 ± 0.002c	0.026 ± 0.004d	0.019 ± 0.005c
	R2	0.024 ± 0.004c	0.023 ± 0.006c	0.024 ± 0.004d	0.022 ± 0.007c
	RF2	0.025 ± 0.004c	0.021 ± 0.003c	0.027 ± 0.002d	0.020 ± 0.005c

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.