Performance evaluation of an ox-drawn ridging plough in a soil-bin.

An ox-drawn ridging plough was developed using the Godwin-Spoor narrow tine soil force prediction model. The plough was evaluated in a sandy loam soil in the soil-bin at Cranfield University, Silsoe. The objectives were to compare predicted with measured draught and vertical forces, and cross-sectional area of soil disturbance respectively. The experiments were arranged in a randomised complete block design with two blocks including ploughing to the right and left within the soil bin. The plough was run at a speed of 0.7m/s at depths between 0.10 and 0.25m at 0.05m intervals. Each run was replicated eight times. The main instrumentation employed was the extended octagonal ring transducer for soil force measurement. A profile gauge was used for taking soil profiles. The measured draught force was 19.9% greater than the predicted force. This was in good agreement with the narrow tine force prediction theory, which suggests that predicted draught and vertical forces should be within 15 – 20% of measured values. The measured vertical force was 37.1% smaller than the predicted force. This was a less satisfactory measure of agreement between predicted and measured force and may be attributed to the complex geometry of the ridging plough compared with the plane shape of the simple tine as used in the Godwin-Spoor tine force model. The measured area of soil disturbed was 52.3% smaller than the predicted area. This was in good agreement with the area prediction approach.Journal of Science and Technology (Ghana) Vol. 27 (2) 2007: pp. 120-12