Tillage Effects on Selected Soil Physical Properties in a Maize-Bean Intercropping System in Mwala District, Kenya
Table 4
Soil crust strength as influenced by time of measurement, tillage practices, and the cropping systems ( seasons).
Soil crust strength (MPa)
Short rains 2012
Long rains 2013
Short rains 2013
3 WAP
7 WAP
10 WAP
15 WAP
4 WAP
6 WAP
10 WAP
16 WAP
4 WAP
8 WAP
12 WAP
17 WAP
Tillage
H
1.034a
1.001
1.272
1.269
1.187a
1.553
1.574
1.469
1.187a
1.350
1.468
0.747ab
HTR
0.905b
1.007
1.088
1.124
1.133a
1.494
1.680
1.526
1.133b
1.282
1.462
0.672c
DP
1.111a
1.055
1.208
1.193
1.188a
1.475
1.708
1.472
1.188a
1.341
1.415
0.728bc
DPH
1.094a
1.023
1.255
1.217
1.136a
1.460
1.671
1.451
1.136b
1.301
1.417
0.769ab
OX
1.136a
1.025
1.256
1.234
1.175a
1.561
1.673
1.478
1.175ab
1.355
1.453
0.807a
SSR
1.111a
1.067
1.230
1.296
1.209a
1.568
1.705
1.519
1.209a
1.357
1.480
0.815a
LSD 5%
0.111
0.106
0.162
0.088
0.047
0.105
0.108
0.069
0.047
0.067
0.053
0.072
Cropping system
Sole bean
1.026
1.032
1.221
1.241
1.177
1.529
1.617b
1.479
1.177
1.314
1.441
0.756
Sole maize
1.086
1.006
1.208
1.204
1.161
1.530
1.713a
1.482
1.161
1.338
1.462
0.749
Intercrop
1.085
1.051
1.225
1.222
1.176
1.496
1.675a
1.496
1.176
1.340
1.445
0.765
LSD 5%
0.072
0.064
0.052
0.036
0.051
0.046
0.047
0.036
0.051
0.041
0.029
0.048
Significance levels
Tillage
0.005
0.741
0.218
0.012
0.018
0.165
0.160
0.193
0.018
0.129
0.085
0.007
Cropping system
0.171
0.369
0.794
0.131
0.773
0.245
<0.001
0.571
0.773
0.374
0.272
0.798
Tillage × cropping system
0.466
0.493
0.406
0.043
0.672
0.151
0.789
0.576
0.672
0.266
0.278
0.935
CV%
3.2
6.9
5.2
4.2
1.6
5.0
1.7
2.8
1.6
1.5
0.9
10.2
Tillage: H: hand hoeing only, HTR: hand hoeing with tied ridges, DP: disc ploughing, DPH: disc ploughing + harrowing, OX: ox-ploughing, and SSR: subsoiling-ripping. Different letters within the columns indicate significant difference at 5% probability level.