DEVELOPMENT AND PERFORMANCE EVALUATION OF A PROTOTYPE POWER TILLER INCORPORATED WITH SPRAY GUN IRRIGATION SYSTEM

Abstract

A relatively low-cost power tiller with a portable irrigation system was designed and simulated using AutoCAD and Autodesk Inventor software and manufactured with locally available materials and components. Its main components include a frame, a CG 125 motorcycle engine, a mouldboard plough, a water pump, two caged wheels, and a reel. The performance of the tilling unit and irrigation system was evaluated on a 14 m by 19 m plot of land. Microsoft Excel was used to analyse the data collected, especially in the calculation of averages and plotting graphs of the PPTISGIS performance parameters. AutoCAD2022 and Autodesk Inventor 2023 were used for modelling and simulation. The parameters measured were speed of operation, wheel revolutions, width and depth of furrow and time. The operating speeds recorded were 0.278 m/s, 0.556 m/s, and 0.833 m/s and the fuel consumption was found to be 25.75 L/ha. The percentage of wheel slip was directly proportional to speeds ranging from 5.03% at 0.278 m/s to 13.04% at 0.833 m/s, giving an average of 9.57%. The theoretical and effective field capacities were 0.889 ha/h and 0.7 ha/h respectively, resulting in a field efficiency of 78.74%. Using a sprinkler with a 6 mm diameter nozzle (circular) for the irrigation system, the pressure was 2.5 bar, pump speed was 1700 rpm, discharge rate was found to be 1.125 L/s, with an application rate of 4.42 mm/h. The coefficient of uniformity was calculated as 76.93%, which fell within the acceptable range of 60% to 90%. The cost-benefit analysis indicated that if the power tiller works for 100 days per year at a discount rate of 28.99%, the benefits to be generated over the period would be enough to offset the initial investment and related costs. Generally, the performance of the developed power tiller with an irrigation system is satisfactory and recommended for use by smallholder farmers. Key words: pressure, performance, sprinkler, tilling, uniformity