56 RES. AGR. ENG., 51, 2005 (2): 56–62 The mouldboard plough has always been the basic tillage implement on the farm. Although historic, it is still useful and widely employed for primary tillage. It cuts the soil slice, lifts it over the surface of the mouldboard and inverts it, burying the surface growth and crop residues to leave a clear surface for subsequent cultivation (BRASSINGTON 1987). Animal traction is an appropriate, afford- able and sustainable technology that is still im- portant throughout Eastern and Southern Africa. Therefore, animal traction technology in terms of draught power requirements is a crucial area of research and development. The animal-drawn mouldboard plough is widely used for primary till- age in the developing counties of Africa. This is due to its low cost and the availability of working animals such as oxen, cows, donkeys, horses and mules. Generally the mouldboard plough works well as a low speed soil inverting implement and improvements in the design can be obtained mainly by reducing draught and wear. It was estimated that the friction component of draught contributes about 30% of the total draught for ploughs work- ing at a speed of 3 km/h (O’CALLAGHAN, MCCOY 1965). According to BETKER and KUTZBACH (1989) draught forces in animal-drawn ploughs vary from 850 N to 2,000 N depending upon the type of the soil and its moisture content. On the other hand the continuous pull available from work oxen is usu- ally taken to be 10% of animal’s body weight (INNS 1990). So that a pair of oxen with a combined body mass of 800 kg would produce a pull of about 800 N. Consequently continuous operation of an imple- ment would be beyond the capacity of an ordinary draught animal pair. In this regard an investigation was undertaken to evaluate the draught require- ment of enamel-coated animal-drawn mouldboard plough and compare its performance with similar uncoated plough under comparable working con- ditions. LITERATURE REVIEW The draught requirements of an animal drawn mouldboard plough is affected by the following fac- tors: the type of soil, soil moisture, speed of plough- ing (which normally does not vary significantly), depth and width of the furrow slice, type of the mouldboard used, as well as soil-to-metal friction characteristics of the soil-engaged components. By reducing the soil-to-metal friction, the draught re- quirement of the plough can be reduced consider- Draught requirements of enamel coated animal drawn mouldboard plough I. A. LOUKANOV 1 , J. UZIAK 1 , J. MICHÁLEK 2 1 Department of Mechanical Engineering, University of Botswana, Gaborone, Botswana 2 Department of Applied Mathematics and Informatics, Masaryk University, Brno, Czech Republic ABSTRACT: he power requirement of tillage implements is an important design consideration particularly for animal-drawn implements where the power is limited. he paper presents the possibility of reduction in the draught requirements of animal-drawn mouldboard plough by using enamel coating on the soil-engaged components such as the mouldboard, share and the landside. Trials were conducted to compare enamel-coated Maun Series single mouldboard plough (manufactured by Zimplow Limited, Bulawayo, Zimbabwe) with similar uncoated plough, both animal-drawn, under comparable working conditions. Experiments were done at 25% and 32% d.b. soil moisture content on a red clay soil in Zimbabwe. he parameters measured in evaluating the draught performance of both ploughs were the tractive effort (pull), speed of ploughing, depth and width of ploughing, and soil conditions (i.e. soil moisture content, soil bulk density and soil penetration resistance). It was found that for similar working conditions the enamel coating reduced the specific draught by 20 to 26% depending upon soil moisture content. Keywords: enamel coating; uncoated plough; enamel-coated plough; actual draught and specific draught