The experiment was conducted at the fields of Agricultural College, University of Basrah,
Qarmat-Ali campus to study the effect of three tandem disc harrow depth (10, 15,and 20cm) and four
forward speed (0.20,0.38,0.46,and 0.60 m/sec) and interaction between them on the tandem disc harrow
energy requirements and soil pulverization ability . A split block in a R.C.B.D. design was used . The
results showed , increasing the tandem disc harrow forward speed from 0.20 to 0.60 m/sec increased the
draft force, pulverization efficiency and specific and equivalent energies by 16%,33%, 42% and 88%
respectively . While the mean weight diameter (Pulverization index) decreased by 23% (Improve
tandem disc harrow performing) . The increasing on depth of tandem disc harrow from 10 to 20 cm
increased the draft force and mean weight diameter (Pulverization index) significantly by 36% , 12%
respectively . While it decreased the specific , equivalent energies and pulverization efficiency by 32% ,
47% and 22% respectively. While the interaction between the forward speed and the depth of tandem
disc harrow have significant effect on the draft force, specific, equivalent energies, pulverization
efficiency , draft power and mean weight diameter (Pulverization index) where the tandem disc harrow
depth from 10 cm and forward speed 0.6 m/sec achieved highest mean weight diameter (Pulverization
index) value was 27.89 mm while tandem disc harrow depth 20 cm forward speed 0.20 m/sec achieved
lower mean weight diameter (Pulverization index) value was 329.89 mm. |