Evaluation of Physicochemical Properties of Sandy-Textured Soils under Smallholder Agricultural Land Use Practices in Sarawak, East Malaysia
Table 4
Surface and subsurface soil physicochemical properties at various agricultural land uses.
Soil physicochemical properties
Secondary forest (SF)
Rubber (R)
Oil palm (OP)
Pepper (P)
n = 6
n = 7
n = 9
n = 4
Surface soil (0–10 cm)
pHw
4.59 ± 0.15a
4.53 ± 0.07a
4.57 ± 0.14a
4.76 ± 0.20a
pHk
3.52 ± 0.24a
3.59 ± 0.26a
3.49 ± 0.18a
3.86 ± 0.11a
EC (µS·cm−1)
26 ± 3a
27 ± 5a
38 ± 5b
26 ± 7a
Total C (g·kg−1)
18.0 ± 3.1a
16.3 ± 4.9a
19.5 ± 7.3a
19.6 ± 4.5a
Total N (g·kg−1)
1.20 ± 0.19a
0.99 ± 0.34a
1.37 ± 0.35a
1.30 ± 0.40a
C/N
15.1 ± 2.1a
16.7 ± 2.0a
13.9 ± 2.1a
15.4 ± 2.0a
CEC (cmolc·kg−1)
4.13 ± 0.56a
3.80 ± 0.68a
4.42 ± 0.99a
4.70 ± 0.68a
Exch. K+ (cmolc·kg−1)
0.11 ± 0.01a
0.09 ± 0.02a
0.08 ± 0.03a
0.10 ± 0.02a
Exch. Mg2+ (cmolc·kg−1)
0.13 ± 0.03a
0.10 ± 0.01a
0.13 ± 0.06a
0.19 ± 0.10a
Exch. Ca2+ (cmolc·kg−1)
0.43 ± 0.10ab
0.27 ± 0.04a
0.30 ± 0.18ab
0.52 ± 0.13b
Exch. Al3+ (cmolc·kg−1)
0.46 ± 0.36a
0.30 ± 0.16a
0.39 ± 0.21a
0.55 ± 0.08a
Sum of basesa (cmolc·kg−1)
0.70 ± 0.10ab
0.49 ± 0.08a
0.68 ± 0.23ab
0.92 ± 0.32b
Effective CECb (%)
1.16 ± 0.34ab
0.79 ± 0.21a
1.08 ± 0.32ab
1.47 ± 0.30b
Al saturationc (%)
35.9 ± 18.2a
8.3 ± 1.6a
35.7 ± 14.2a
38.3 ± 8.4a
Available P (mg·kg−1)
3.7 ± 2.0a
8.3 ± 1.6a
19.4 ± 10.6a
65.9 ± 29.7b
Clay (%)
15.9 ± 7.9a
10.0 ± 2.3a
11.1 ± 4.6a
13.8 ± 1.8a
Silt (%)
11.9 ± 2.0a
9.3 ± 4.4a
10.8 ± 9.1a
13.2 ± 7.6a
Sand (%)
72.2 ± 8.4a
80.7 ± 5.7a
78.1 ± 7.9a
73.0 ± 7.0a
Bulk density (g·mL−1)
1.05 ± 0.10a
1.09 ± 0.16ab
1.23 ± 0.07ab
1.26 ± 0.06b
Hardnessd (mm)
12 ± 4a
13 ± 2a
15 ± 1a
20 ± 3b
Subsurface soil (30–40 cm)
pHw
4.95 ± 0.21ab
5.07 ± 0.19ab
5.19 ± 0.10b
4.83 ± 0.23a
pHk
3.94 ± 0.20ab
4.29 ± 0.18b
4.00 ± 0.24ab
3.83 ± 0.32a
EC (µS·cm−1)
11 ± 2a
12 ± 2a
12 ± 2a
23 ± 7b
Total C (g·kg−1)
6.8 ± 3.1a
12.3 ± 5.7a
8.4 ± 4.1a
10.6 ± 1.4a
Total N (g·kg−1)
0.40 ± 0.14a
0.48 ± 0.15a
0.54 ± 0.14a
0.46 ± 0.10a
C/N
16.6 ± 4.8a
25.1 ± 6.0a
15.4 ± 5.3a
23.8 ± 6.7a
CEC (cmolc·kg−1)
1.67 ± 0.83a
1.91 ± 0.56a
1.82 ± 0.71a
2.00 ± 0.69a
Exch. K+ (cmolc·kg−1)
0.02 ± 0.01a
0.02 ± 0.01a
0.02 ± 0.01a
0.04 ± 0.02a
Exch. Mg2+ (cmolc·kg−1)
0.08 ± 0.02b
0.06 ± 0.02ab
0.04 ± 0.03a
0.07 ± 0.01ab
Exch. Ca2+ (cmolc·kg−1)
0.28 ± 0.01ab
0.24 ± 0.03ab
0.19 ± 0.07a
0.36 ± 0.16b
Exch. Al3+ (cmolc·kg−1)
0.49 ± 0.36a
0.37 ± 0.20a
0.43 ± 0.20a
0.60 ± 0.17a
Sum of basesa (cmolc·kg−1)
0.48 ± 0.03ab
0.37 ± 0.05ab
0.30 ± 0.13a
0.51 ± 0.17b
Effective CECb (%)
0.96 ± 0.37a
0.74 ± 0.23a
0.73 ± 0.18a
1.10 ± 0.26a
Al saturationc (%)
44.3 ± 18.9a
47.0 ± 12.4a
57.5 ± 20.0a
53.9 ± 11.3a
Available P (mg·kg−1)
1.4 ± 1.0a
6.2 ± 3.1b
3.1 ± 1.6ab
4.3 ± 2.0ab
Clay (%)
13.6 ± 8.8a
11.8 ± 4.1a
13.1 ± 5.5a
15.2 ± 3.8a
Silt (%)
16.6 ± 3.2ab
10.2 ± 3.7a
13.0 ± 7.3ab
22.4 ± 9.7b
Sand (%)
69.8 ± 9.5ab
78.0 ± 6.3b
73.9 ± 7.9ab
62.5 ± 9.2a
Bulk density (g·mL−1)
1.64 ± 0.09a
1.47 ± 0.15a
1.56 ± 0.12a
1.55 ± 0.07a
Hardnessd (mm)
17 ± 2a
18 ± 2a
20 ± 2a
19 ± 1a
Values are means ± standard deviation; values in the same row followed by different letters indicate significant differences at 5% levels using Scheffe’s multiple comparison test. aSum of exchangeable K+, Mg2+, Ca2+, and Na+; bsum of exchangeable bases and exchangeable Al; cexchangeable Al in percent of ECEC; dmeasured using Yamanaka-type push cone penetrometer.