Association between Soil Fertility and Growth Performance of Planted Shorea macrophylla (de Vriese) after Enrichment Planting at Rehabilitation Sites of Sampadi Forest Reserve, Sarawak, Malaysia

Table 2

(a) Means and standard deviation of surface soil physicochemical properties at rehabilitation sites (SM96, SM97, SM98, and SM99) and secondary forest (SF). (b) Means and standard deviation of subsurface soil physicochemical properties at rehabilitation sites (SM96, SM97, SM98, and SM99) and secondary forest (SF).

(a)

Age-since-planting/soil physicochemical properties		Rehabilitation sites				Secondary forest
		SM96; (18 years)	SM97; (17 years)	SM98; (16 years)	SM99; (15 years)	SF; (30 years)
Surface soil, 0–10 cm depth
pH (H2O		4.69 ± 0.12	4.67 ± 0.09	4.72 ± 0.08	5.20 ± 0.06	5.29 ± 0.26
pH (KCl		3.92 ± 0.08	3.63 ± 0.56	4.07 ± 0.05	4.31 ± 0.07	4.16 ± 0.15
E	(µS cm^−1)	120.0 ± 13.3	163.2 ± 32.9	165.7 ± 51.0	193.6 ± 10.6	188.2 ± 25.2
SO	(%)	6.63 ± 1.71	8.54 ± 1.51	8.91 ± 2.06	8.52 ± 0.83	9.30 ± 1.40
Total	(g kg^−1)	38.5 ± 9.9	49.6 ± 8.8	51.7 ± 12.0	49.4 ± 4.8	53.9 ± 8.1
Total	(g kg^−1)	2.16 ± 0.67	2.55 ± 0.38	2.99 ± 1.01	2.91 ± 0.80	3.05 ± 0.50
C/N ratio		18.27 ± 2.89	19.54 ± 3.00	18.22 ± 4.55	17.74 ± 3.46	17.78 ± 1.43
CE	( kg^−1)	11.8 ± 2.8	9.7 ± 1.6	9.5 ± 1.6	8.4 ± 3.0	10.2 ± 1.2
Exch. Ca^2+	( kg^−1)	0.52 ± 0.17	0.48 ± 0.25	0.68 ± 0.25	0.26 ± 0.28	0.54 ± 0.43
Exch. Mg^2+	( kg^−1)	0.33 ± 0.07	0.35 ± 0.17	0.24 ± 0.09	0.30 ± 0.04	0.38 ± 0.20
Exch.	( kg^−1)	0.15 ± 0.04	0.12 ± 0.02	0.18 ± 0.03	0.17 ± 0.03	0.32 ± 0.03
Exch. A	( kg^−1)	2.54 ± 0.82	4.03 ± 0.40	1.35 ± 0.19	1.56 ± 0.24	1.40 ± 0.41
SU	( kg^−1)	1.45 ± 0.23	1.35 ± 0.42	1.36 ± 0.35	0.84 ± 0.32	1.77 ± 0.62
ECE	( kg^−1)	3.99 ± 1.01	5.38 ± 0.40	2.71 ± 0.51	2.40 ± 0.44	3.16 ± 0.65
Base saturation	(%)	12.6 ± 2.3	14.3 ± 4.8	14.1 ± 1.6	11.5 ± 6.4	17.2 ± 5.5
Available	(mg P kg^−1)	14.0 ± 2.1	13.6 ± 1.5	6.3 ± 1.0	2.4 ± 1.1	5.5 ± 1.2
Al saturation	(%)	62.9 ± 5.1	75.0 ± 6.7	50.4 ± 4.4	65.8 ± 7.6	44.5 ± 13.6
	(%)	29.0 ± 8.8	36.9 ± 5.8	41.2 ± 7.2	40.3 ± 6.7	45.9 ± 1.9
	(%)	21.8 ± 5.9	33.8 ± 4.2	5.1 ± 2.7	6.8 ± 3.3	6.4 ± 2.1
Sand	(%)	49.1 ± 11.9	29.3 ± 7.1	53.7 ± 7.4	53.0 ± 9.1	47.7 ± 2.6
Bulk density	(g mL^−1)	1.08 ± 0.07	0.92 ± 0.13	1.01 ± 0.09	0.93 ± 0.08	0.90 ± 0.04
Particle density	(g mL^−1)	2.52 ± 0.16	2.49 ± 0.15	2.32 ± 0.18	2.83 ± 0.65	2.42 ± 0.09
Moisture content	(%)	3.0 ± 0.9	4.4 ± 0.5	3.6 ± 0.5	4.0 ± 0.7	4.0 ± 0.2

Values in the same row indicate means ± standard deviation, : electrical conductivity, ; soil organic matter, C: total carbon; N: total nitrogen; : cation exchange capacity; of exchangeable bases (Ca, Mg, K, and Na); ; effective CEC, sum of exchangeable bases and exchangeable Al. are significant at 5% and 1% levels, respectively, among the rehabilitation sites.

(b)

Age-since-planting/Soil physicochemical properties		Rehabilitation sites				Secondary forest
		SM96; (18 years)	SM97; (17 years)	SM98; (16 years)	SM99; (15 years)	SF; (30 years)
Subsurface soil, 30–40 cm depth
pH (H2O		5.01 ± 0.05	5.04 ± 0.05	5.35 ± 0.16	5.29 ± 0.05	5.38 ± 0.05
pH (KCl		3.91 ± 0.06	3.72 ± 0.04	4.27 ± 0.05	4.33 ± 0.06	4.48 ± 0.05
	(µS cm^−1)	52.7 ± 7.0	54.6 ± 2.9	47.5 ± 7.9	122.3 ± 1.9	132.9 ± 13.3
	(%)	3.88 ± 0.90	4.03 ± 0.74	4.44 ± 0.85	4.70 ± 0.84	5.97 ± 0.89
Total	(g kg^−1)	22.6 ± 5.2	23.4 ± 4.3	25.8 ± 4.9	27.3 ± 4.9	34.6 ± 5.1
Total	(g kg^−1)	0.95 ± 0.44	1.06 ± 0.17	1.07 ± 0.29	1.34 ± 0.30	1.61 ± 0.41
C/N ratio		26.25 ± 8.03	22.10 ± 3.40	24.70 ± 3.97	20.62 ± 3.28	22.00 ± 2.95
CE	( kg^−1)	7.8 ± 2.3	7.3 ± 1.4	7.0 ± 1.4	7.7 ± 1.7	9.3 ± 0.9
Exch. Ca^2+	( kg^−1)	0.13 ± 0.05	0.17 ± 0.07	0.43 ± 0.19	0.02 ± 0.02	0.07 ± 0.05
Exch. Mg^2+	( kg^−1)	0.12 ± 0.04	0.15 ± 0.10	0.11 ± 0.07	0.11 ± 0.01	0.14 ± 0.07
Exch.	( kg^−1)	0.06 ± 0.02	0.06 ± 0.01	0.08 ± 0.02	0.11 ± 0.02	0.25 ± 0.06
Exch. A	( kg^−1)	2.72 ± 1.18	4.30 ± 0.66	1.30 ± 0.30	1.56 ± 0.17	1.81 ± 0.23
	( kg^−1)	0.65 ± 0.19	0.76 ± 0.16	0.86 ± 0.30	0.32 ± 0.04	0.89 ± 0.30
ECE	( kg^−1)	3.37 ± 1.33	5.06 ± 0.76	2.16 ± 0.44	1.88 ± 0.16	2.69 ± 0.38
Base saturation	(%)	8.6 ± 2.4	10.4 ± 1.5	12.6 ± 4.1	4.3 ± 0.9	9.5 ± 3.0
Available	(mg P kg^−1)	5.9 ± 1.5	3.7 ± 0.4	2.6 ± 1.3	3.3 ± 1.9	0.9 ± 0.3
Al saturation	(%)	79.0 ± 7.6	85.0 ± 2.3	60.5 ± 9.4	82.9 ± 3.0	67.6 ± 8.9
Clay	(%)	31.2 ± 6.9	37.7 ± 6.4	36.1 ± 8.6	36.5 ± 5.8	48.1 ± 2.5
	(%)	25.8 ± 5.8	30.9 ± 2.8	8.7 ± 7.5	8.7 ± 3.5	4.9 ± 1.1
	(%)	43.0 ± 7.0	31.4 ± 8.7	55.2 ± 13.2	54.9 ± 3.8	47.0 ± 2.9
Bulk density	(g mL^−1)	1.32 ± 0.14	1.11 ± 0.04	1.36 ± 0.12	1.35 ± 0.18	1.13 ± 0.19
Particle density	(g mL^−1)	2.50 ± 0.15	2.53 ± 0.09	2.40 ± 0.14	2.68 ± 0.14	2.62 ± 0.27
Moisture content	(%)	2.6 ± 0.9	3.7 ± 0.7	2.8 ± 0.6	3.3 ± 0.7	3.7 ± 0.4

Values in the same row indicate means ± standard deviation, : electrical conductivity, ; soil organic matter, C: total carbon; N: total nitrogen; : cation exchange capacity; of exchangeable bases (Ca, Mg, K, and Na); ; effective CEC, sum of exchangeable bases and exchangeable Al. are significant at 5% and 1% levels, respectively, among the rehabilitation sites.