Abstract:
Crop production is the business of maximising profit in growing crops for food, feed and fibre, while ensuring environmental sustainability. Profit maximisation implies reduction in the cost of field operation while environmental sustainability requires that the soil be left in state in which it serves the next generation optimally. Unfortunately, tillage that is meant to prepare the soil for improved crop production has been described as the single most expensive factor in crop production, and yet leaves the soil in an undesirable condition of compaction in the long run owing to the heavy machineries used, thereby negating the principle of sustainability. A lot of research has gone into proffering solutions to these problems but most have not considered the contribution of implement weight to the problem. It is generally believed that higher implement weight aids tool soil penetration. This work therefore aims at studying the actual effect of implement weight on the depth of cut of the disc plough in a gravelly sandy soil. A two factor Latin Square with repeated treatment of weight was used to study the effects of weight on depth of cut using ANOVA. Factors considered were tilt angle (α1=16°, α2=22°, α3=26°,), disc angle (β1=37°, β2=40°, β3=43°) and weight (λ1=253.1kg, λ2=327.7kg, λ3=370.4kg). The implement was powered by a 47.7kW (64 hp) tractor, weighing 2757 kg. Results obtained showed that there was insufficient evidence to prove that implement weight had significant effect on the depth and width of cut of the disc plough. Disc angle was significant on width of cut at 5% only while tilt angle was significant on both depth and width of cut, even at 1%. It may be concluded therefore that varying the weight of the disc plough may not significantly affect its depth and width of cut, and that depth and width of cut are affected by tilt angle while disc angle only affected the width of cut. It is recommended from this result, that ploughs with lighter weight be designed so as to be pulled by smaller tractors to reduce energy requirement and soil compaction
