Comparison between the performance of a movable boards ditch opener and conventional ditch opener in cultivated and uncultivated soils Part 1: The draft force

The draft force of the movable boards ditch opener (MB) was compared with that of the conventional ditch opener (CD). The parameters of the experiments were three operating depths (30, 40 and 50 cm), three angles between the boards of MB (45, 60 and 75º), the angle of the boards of CD was constant (65º), three wings widths of the foot of MB whereas, one share width (35cm) for CD and two soil types (cultivated and uncultivated soils). The texture of soils was silty clay. The results showed that MB can penetrate the soil to the required depth easily and its draft force requirements were lower than that for CD for all operating depths, angle between the boards and in the cultivated and in uncultivated soils. Whereas, CD could not penetrate the soil more than 25cm in the uncultivated soil that its draft force higher than that for MB for operating depth of 30 and 40 cm and for all angles between the boards but the contrary occurred with operating depth of 50cm. The draft force requirement of MB increased slightly with the angle between the boards but it MB increased considerably with increasing wings width of the foot. However, the wings of MB required less draft force than the share of CD which its width was 35 cm (constant width). MB surpassed CD in the field performance, it required less draft force and it could penetrate the soils easily.