Fresh and Composted Paper Sludges Sustain Soil Productivity
Table 5
Direct and residual effects of applications of fresh and composted paper sludges, and N fertilizer on yield and N uptake of silage corn (2001 to 2003) and barley (2004).
Treatments
Growing seasons (year)
2001
2002
2003
2004
2001
2002
2003
2004
Yields
N uptake
Silage corn
Barley
Silage corn
Barley
Mg ha-1
kg ha-1
Frequency (single application)
Control
8.5
6.4
10.6
2.4
81.1
47.5
125
37.37
N fertilizer (160 kg N ha-1)
13.6
12.0
14.0
2.5
149.4
122.9
163
38.08
FDS
11.1
8.9
14.4
2.8
118.5
78.5
173
43.51
CDS
8.4
7.1
11.8
2.8
72.2
54.1
137
43.59
FDS + 120 kg N ha-1
14.1
13.0
14.2
2.8
137.0
128.8
166
44.6
CDS + 120 kg N ha-1
13.2
11.8
13.9
3.1
117.4
104.6
164
47.3
Frequency (triple application)
Control
8.8
7.0
12.4
2.4
88.8
55.6
139
37.13
N fertilizer (160 kg N ha-1)
14.7
12.4
13.6
2.3
166.5
128.7
163
34.37
FDS
10.7
8.7
14.2
3.3
116.3
75.8
165
51.37
CDS
8.5
7.3
13.4
2.8
74.9
59.8
151
43.9
FDS + 120 kg N ha-1
14.5
12.5
14.1
3.1
144.5
123.4
164
48.56
CDS + 120 kg N ha-1
14.3
12.8
14.6
2.7
128.7
126.7
176
43.36
ANOVA F values
Treatments
1.16
1.52
3.33
Frequency
1.4
0.6
0.39
0.06
1.6
1.9
0.00
0.10
Treatments × Frequency
0.4
0.4
0.39
0.97
0.2
0.9
1.22
0.74
Contrasts
(1) Control versus others
0.01
2.35
(2) N fert. versus FDS and CDS
0.00
0.02
(3) FDS versus CDS
1.81
1.23
1.17
0.86
(4) versus
0.03
0.21
0.10
0.05
(5) versus
3.93
0.26
3.96
0.18
. and .01 probability levels of statistically significant difference, respectively. , : fresh paper sludges alone or with N fertilizer, respectively. , : composted paper sludges alone or with N fertilizer, respectively.
