Abstract

A predictive model for the determination of optimum fuel consumption of a tractor during ridging operation has been developed. The model development involved field experimentations to determine the various parameters affecting tractor fuel consumption, like draught, speed, depth of cut, soil moisture content, cone index and width of cut. The field investigations were carried out at the farm of Rivers State Agricultural Development Programme in Port Harcourt, Nigeria. The field experimental design adopted was the Factorial in Randomized Complete Block Design (RCBD). It consisted of 9 experimental treatments with three replications. The experimental land area was 160 m by 32.5 m (5200 m2), which was sub-divided into three blocks of 9 plots each, measuring 50 m by 2.5 m, with an inter-plot spacing of 1 m provided for different treatment options. The experimental fuel consumption was determined from measuring the actual amount of fuel used by the tractor per unit time. The model equation was then formulated using the Buckingham pi theorem. The model showed that tractor fuel consumption during ridging is directly proportional to the draught, ridging speed, height of ridge and moisture content; and inversely proportional to the penetration resistance and width of cut. The model was validated by graphical comparison and with root mean square error and paired t-Test. The results obtained showed that there was no significant difference between the measured and predicted values at 95 and 99% confidence limits; and the model can accurately predict tractor fuel consumption during ridging operations using a disc ridger.

Key words: Buckingham pi theorem, disc ridger, fuel consumption, predictive model, ridge height, ridging operation, ridging speed, tractor.