A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1988

In an effort to reduce the energy requirements of the tillage tools in a farming operation, a study was conducted to investigate the effect of enamel coating on floats and the mouldboard plough, under controlled laboratory conditions in Bangkok clay soil at different soil moistures and travel speeds. The Friction characteristics of enamel improved the scouring and reduced the Draft requirements of both the enamel coated floats and mould boardplough. A reduction of 30 to 50 % in drag of floats was recorded in Teflon and Enamel coated floats under dry and wet soils (14 - 31 %, soil m. c.). In puddled saturated soil, a 11 - 30 % decrease in drag was observed for enamel and Teflon coated floats respectively. The overall performance of the enamel coated float was better than other coatings namely; Teflon, Zinc and Mild- steel at all moisture levels. Qualitative observations indicated enamel to be more resistant to abrasion than Teflon and Zinc and Enamel showed better scouring qualities operating in dry soils, ( 16% m.c. db) showed a decrease in draft of 19- 22% for the speed range of 1 - 3 km/hr. In wet unsaturated soils (21 & 31 %), 3 to 28% reduction in plough draft was noticed in the same speed range. Puddled saturated soil (51 & 58% m.c. db) also gave 3 to 28 % reduction in draft in the same speed range (1 - 3 Km/hr.). In saturated soils, low travel speed gave higher reduction (28%) in plough draft. In wet soils the scouring of the enamel was much better than the uncoated one. A cyclic nature of the plough forces was observed.