Composting for a More Sustainable Palm Oil Waste Management: A Systematic Literature Review
Table 5
The analysis results on physicochemical parameters and macro- and micronutrient content of palm oil waste compost.
Parameter
Physicochemical
Moisture
75
8
−0.946 [−1.440; −0.452]
<0.001
93.40% (<0.001)
0.039
pH
95
8
0.968 [0,520; 1.415]
<0.001
48.54% (0.015)
0.001
C-organic
135
8
0.926 [0.572; 1.280]
<0.001
92.90% (0.003)
0.001
N-total
135
8
2.19 [1.762; 2.616]
<0.001
93.35% (<0.001)
<0.001
C/N ratio
120
8
0.407 [0.029; 0.785]
0.035
82.28% (<0.001)
0.001
Macro- and microcomponents
P
125
8
0.698 [0.321; 1.076]
<0.001
60.51% (0.118)
<0.001
K
125
8
0.847 [0.464; 1.230]
<0.001
35.41% (0.242)
<0.001
Ca
70
8
−57.6 [−67.191; −48.072]
<0.001
0% (0.557)
ns
Mg
95
8
−0.212 [−0.641; 0.217]
ns
34.46% (0.267)
ns
S
18
8
−0.33 [−1.34; 0.68]
ns
10.18% (0.355)
0.155
Fe
24
8
0.99 [−1.32; 3.30]
ns
83.66% (0.033)
0.005
Zn
18
8
5.64 [2.36; 8.91]
<0,001
52.94% (0.047)
0.013
Mn
18
8
1.33 [−2.20; 4.85]
ns
88.75% (0.007)
0.008
Cu
24
8
3.38 [0.64; 6.12]
0.016
76.45% (0.003)
<0.001
Description: N = number of samples used in the study; k = number of studies used in the analysis; SMD = standardized mean difference is a summary of each study with the effect size; = value; I2 = inconsistency (heterogeneity test); Egger’s = publication bias test; ns = not significant.
