Coapplication of Chicken Litter Biochar and Urea Only to Improve Nutrients Use Efficiency and Yield of Oryza sativa L. Cultivation on a Tropical Acid Soil
Table 6
Effects of biochar and nitrogen fertilization on soil chemical properties in the field study.
Treatment
T1
T2
T4
T5
T6
T7
T8
Before
pHw
4.6a ± 0.16
4.6a ± 0.20
4.9a ± 0.20
4.9a ± 0.19
5.0a ± 0.14
4.7a ± 0.17
4.5a ± 0.11
4.9a ± 0.04
%
Organic matter
7.5c ± 0.65
8.3c ± 1.38
15.3a ± 1.55
13.0a ± 0.95
14.3ab ± 0.91
13.3a ± 0.25
14.5a ± 0.95
10.8bc ± 0.85
Total carbon
0.87c ± 0.07
0.96c ± 0.16
1.77a ± 0.18
1.51a ± 0.11
1.65b ± 0.11
1.54a ± 0.03
1.68a ± 0.11
1.25bc ± 0.10
Total N
0.04b ± 0.008
0.05b ± 0.013
0.11a ± 0.013
0.11a ± 0.013
0.09ab ± 0.013
0.09ab ± 0.007
0.07b ± 0.008
0.05b ± 0.007
mg kg−1
Available
0.88a ± 0.18
1.05a ± 0.20
2.10a ± 0.29
1.75a ± 0.20
1.75a ± 0.20
1.93a ± 0.34
1.40a ± 0.29
1.05a ± 0.35
Exchangeable
1.93d ± 0.18
3.33d ± 0.34
3.68cd ± 0.18
2.80a ± 0.08
2.98bc ± 0.15
2.98abc ± 0.18
2.28ab ± 0.22
1.58abc ± 0.18
Available P
1.14a ± 0.18
2.64a ± 0.21
3.60a ± 0.54
4.88a ± 0.82
4.03a ± 0.74
2.64a ± 0.49
3.34a ± 2.08
2.84a ± 0.64
Total P
68.03a ± 12.99
77.35a ± 6.39
77.06a ± 7.97
86.22a ± 8.08
74.02a ± 5.63
83.05a ± 8.31
76.94a ± 2.29
64.80a ± 4.64
cmol kg−1
Total K
2.89a ± 0.56
2.28a ± 0.17
1.76a ± 0.28
2.22a ± 0.81
1.92a ± 0.14
2.87a ± 1.12
2.65a ± 0.80
3.30a ± 1.14
Available K
0.40d ± 0.05
1.07ab ± 0.05
0.71bc ± 0.05
0.75bc ± 0.03
0.99ab ± 0.18
0.66cd ± 0.06
0.37d ± 0.06
1.01ab ± 0.12
CEC
2.88c ± 0.18
2.75c ± 0.36
6.65ab ± 0.68
5.93ab ± 0.22
5.55ab ± 0.54
7.25a ± 0.48
6.50ab ± 0.59
4.58bc ± 0.10
Exchangeable Acidity
1.10ab ± 0.04
1.06abc ± 0.13
0.73cd ± 0.05
0.74cd ± 0.05
0.55d ± 0.04
0.79bcd ± 0.09
0.68d ± 0.06
1.32a ± 0.07
Exchangeable Al3+
0.91a ± 0.06
0.71b ± 0.07
0.43d ± 0.04
0.40d ± 0.01
0.36d ± 0.03
0.52d ± 0.04
0.49bc ± 0.03
1.24cd ± 0.05
Exchangeable H+
0.19a ± 0.07
0.35a ± 0.06
0.30a ± 0.08
0.34a ± 0.06
0.19a ± 0.03
0.27a ± 0.05
0.19a ± 0.07
0.08a ± 0.02
Exchangeable Cu2+
0.0076a ± 0.0004
0.0069b ± 0.0002
0.0069b ± 0.0009
0.0060ab ± 0.0005
0.0052ab ± 0.0010
0.0032ab ± 0.0001
0.0067b ± 0.0002
0.0119ab ± 0.0006
Exchangeable Mn2+
0.44a ± 0.06
0.39a ± 0.07
0.37a ± 0.05
0.37a ± 0.06
0.40a ± 0.04
0.56a ± 0.05
0.33a ± 0.07
0.27a ± 0.07
Exchangeable Fe2+
1.88b ± 0.08
1.82a ± 0.07
0.15b ± 0.10
0.04b ± 0.01
0.06b ± 0.01
0.05b ± 0.02
0.08a ± 0.01
0.16b ± 0.01
Exchangeable Zn2+
0.0017a ± 0.0004
0.0018b ± 0.0009
0.0011ab ± 0.0003
0.0009b ± 0.0002
0.0023b ± 0.0011
0.0018ab ± 0.0012
0.0037b ± 0.0019
0.0068b ± 0.0008
Exchangeable Na+
5.21a ± 0.34
4.77a ± 0.21
4.49a ± 0.09
4.43a ± 0.08
4.68a ± 0.18
4.32a ± 0.15
4.87a ± 0.63
5.25a ± 0.39
Exchangeable Ca2+
17.70a ± 1.37
18.12b ± 1.23
19.41b ± 1.17
19.82ab ± 0.70
18.96ab ± 1.93
19.90ab ± 0.47
16.89b ± 1.85
26.39ab ± 2.76
Exchangeable Mg2+
14.79b ± 0.28
12.22a ± 2.01
11.23a ± 1.30
11.42ab ± 0.56
12.14ab ± 1.48
15.55a ± 1.31
13.23a ± 2.25
5.27a ± 0.93
Different letters within a row indicate significant difference between means of four replicates ± standard error using Tukey’s test at ≤ 0.05.