The assessment of agricultural mechanization in Uganda: Perspective engineering options and strategies

The goal of this four-part study was to assess technical constraints of agricultural mechanization in Uganda and providing engineering interventions. The prevalent hand power farming should be supplemented separately or in combination with either draft animal or engine power mechanization. In the first part, optimization model based on minimizing an objective cost function subject to timelessness and draft power constraints was developed. This model is useful in selecting small tractors suitable for developing countries. The emphasis, however, should be on draft animal power.;The second part focused on draft animal power. An interactive computer program projecting labor and draft animal demand throughout the season was developed. This package, adaptable for each agricultural zone, is useful to farmers for advance planning through extension services. Furthermore it was concluded that the following engineering research is needed: characteristic performance of traction animals; adaptive design of draft animal implements and equipment suitable for local traction animals; and draft animal-operator ergonomics. These research priorities necessitate a system for testing traction animals. Therefore there is a need to develop an inexpensive dynamometer for that purpose.;The third part was concerned with the design and development of a mobile traction animal dynamometer system. The system consisted of: a loading cart for creating tractive loading; and instrumentation for measuring mechanical and physiological parameters of the draft animal. The resistive torque on the rear wheels, with appropriate ballast, is created by actuating a chain driven band brake. Instrumentation consisted of telemetric bi-polar heart rate monitors and veterinary rectal probes complete with a digital thermometer.;The last part of the study was to evaluate the prototype system with preliminary test of characteristic performance of a pair of Shorthorn oxen. The team exerted drawbar pull equivalent to 5, 10, 15 and 20 percent of their nominal weight. At the end of a specified work-cycle for each level of pull, the physiological parameters were measured. The speed of the team ranged from 1.5 to 1.2 m/s. When the animals exerted drawbar pull exceeding 14 percent of their body weight an accelerated increase in the rate of change of the heart rate occurred.