A survey of reliability of tillage equipment in Osun State, Nigeria

Abstract

Reliability of tillage equipment in Osun State, Nigeria was investigated by using Weibull function. Frequencies of breakdown and time of failure of the implements were collected and analyzed using Weibull method. Results obtained showed that harrows were the most reliable followed by ridger and the plough respectively. Disc blade, disc gang and bearing failed in use while other components show no fault. The study showed that actual efficiency of operation was very low compared to the theoretical efficiency designed by the manufacturer. Theoretical efficiency of plough, harrow and ridger were 46%, 22% and 71% respectively. Overall Weibull parameters for plough were (α = 28.49 and β= 6.0 with t50 = 26.85), for harrow, the disc blade had the highest parameters of α = 22.36 and β = 8.80 with t50 = 21.45 but the bearing showed the least α = 11.47, β = 9.30 and t50 = 11.03. Overall harrow parameters were (α = 22.42, β = 8.30 and t50 = 21.45). Mast and spacer spool showed no faults at all. The top link hitch point had the highest parameters of α = 93.36, β = 5.35 and t50 = 87.49. The least α parameter was ‘bearing’ with α = 14.54, β = 1.04 and t50 = 10.22. Overall ridger parameters were (α = 24.29, β = 6.0 and t50 = 22.81). Harrow showed low incidence of breakdown, hence, it was more reliable than ridger and plough.  Variation in the theoretical and actual field efficiency and capacity were due to many factors such as travel time to the field, down time on the field and competence level of operator, terrain, soil conditions and vegetation as most of the implements were designed to suite working conditions of the temperate countries. Repair and maintenance of facilities affected the reliability of the implements. Lack of genuine spare parts, few or lack of special repair and maintenance tools and improper record keeping habits account for the observed reliability. Efficiencies of these implements were affected by the period of operation per day, speed of operation and effective width of implements.

Key Words: Tillage, equipment, reliability, Soil conditions, Implement breakdown