dc.description.abstract | The geometry of four ploughs was characterised by
taking various angular and linear measurements of the
salient features of the plough body based on the method
described by Boer (1966). Two of the ploughs were Kenyan
manufactured, (Bukura Mk. II and victory plough) while the
other two ploughs were manufactured by a company in
Holland, (Rumptstad: winding and cylindrical bottoms).
The specific resistances in sand of the four ploughs
were evaluated as a measure of plough performance under
three different soil conditions (blocks). The performance
of these ploughs was evaluated between the speed range:
0.49 m/s to 1.04 m/s this is the speed that draught animals
would be expected to operate at. The soil condition was
characterised with respect to the following parameters:
soil bulk density, soil moisture content, adhesion,
coefficient of soil-metal friction, cohesion, internal
angle of friction and the soil particle size distribution.
The performance of the ploughs was modeled using the
technique attributed to Goryachkin (1927). The average
modeling results from the three blocks compared well with
the average results obtained experimentally .. | en |