The Impact of Nickel Mining on Soil Properties and Growth of Two Fast-Growing Tropical Trees Species

Table 1

Chemical properties of soils from natural forest and post-nickel mining land. Different letters within row indicate significant difference () by t-test. Mean ± standard error are shown (n = 15).

Chemical properties	Natural forest		Postmining land		Change (%)
pH (H2O)	5.02 ± 0.10	b	6.31 ± 0.05	a	+1.29 (26)
pH (KCl)	4.66 ± 0.10	b	6.31 ± 0.07	a	+1.65 (35)
Total carbon (g/kg)	40.20 ± 0.25	a	2.90 ± 0.05	b	−37.30 (93)
Total nitrogen (g/kg)	2.60 ± 0.02	a	0.057 ± 0.01	b	−2.54 (98)
C/N (ratio)	15.84 ± 0.29	b	65.12 ± 8.72	a	+49.28 (311)
Available P (mg P2O5/kg)	12.30 ± 0.02	a	11.00 ± 0.02	b	−1.30 (11)
CEC (cmol kg^-1)	8.23 ± 0.67	a	3.15 ± 0.71	b	−5.08 (62)
Ca (mg/kg)	5.85 ± 0.93	a	0.86 ± 0.29	b	−4.99 (85)
Mg (mg/kg)	7.32 ± 0.81	a	6.27 ± 1.18	a	−1.05 (14)
K (mg/kg)	10.84 ± 6.23	a	5.25 ± 5.25	a	−5.59 (52)
Na (mg/kg)	0.81 ± 0.19	a	0.21 ± 0.08	b	−0.6 (74)
Fe (mg/kg)	2.12 ± 0.09	a	38.30 ± 18.73	a	+36.18 (1707)
Ni (mg/kg)	3.30 ± 0.33	a	3.17 ± 0.45	a	−0.13 (4)