Fresh and Composted Paper Sludges Sustain Soil Productivity
Table 2
Residual effects of applications of fresh and composted paper sludges, and N fertilizer on soil water-stable aggregates in 2004.
Treatments
Aggregates (%)
mm
5 mm
2–5 mm
2–1 mm
1–0.25 mm
Frequency ()
Control
29.42
23.35
2.79
5.92
2.62
N fertilizer (160 kg N ha-1)
32.35
21.03
2.13
3.05
2.89
FDS
34.94
23.04
2.36
3.20
3.13
CDS
36.78
26.35
1.96
2.79
3.0
FDS 120 kg N ha-1
30.12
26.53
3.10
4.36
2.96
CDS 120 kg N ha-1
32.32
26.07
2.07
2.94
2.92
Frequency ()
Control
27.15
21.42
6.01
8.99
2.51
N fertilizer (160 kg N ha-1)
32.99
21.78
1.92
2.99
2.95
FDS
36.33
22.57
2.99
3.67
3.16
CDS
36.15
23.24
2.52
3.03
3.22
FDS 120 kg N ha-1
31.84
21.72
3.25
4.49
3.10
CDS 120 kg N ha-1
31.71
25.68
3.07
1.75
3.07
ANOVA F values
Treatments
Frequency
0.56
0.29
1.99
0.24
0.75
Treatments Frequency
0.99
1.71
2.47
1.34
0.67
Contrasts
(1) Control versus others
(2) N fert. versus FDS and CDS
0.00
2.20
2.89
0.30
(3) FDS versus CDS
0.48
0.12
1.35
(4) versus
2.14
0.69
3.36
0.33
(5) versus
0.03
2.30
2.23
0.10
. and .01 probability levels of statistically significant difference, respectively. , mean-weight diameter (unit: mm) of soil aggregates. , : fresh paper sludges alone or with N fertilizer, respectively. , CDSN: composted paper sludges alone or with N fertilizer, respectively. , : Single and triple: one application in 2000, and three successive applications in 2000, 2001, and 2002, respectively.
