A FIELD MACHINERY CAPACITY SELECTION MODEL FOR TILLAGE OPERATIONS IN NIGERIA
Keywords:
Farm mechanization, Field machinery cost models, Minimum-cost tillage machinery selection, Field machine capacity.Abstract
A machinery size selection model and annual cost model were developed for heavy tillage implements. The model
development was based on differential calculus as in Hunt-Wilson’s least-cost tillage width model. Field processing
labour cost was considered and the Hunt-Wilson model’s need for prior arbitrary width-dependent machinery
capacity input for width selection circumvented. The model was validated with data from tillage operations of the
machinery hiring unit of Anambra State Ministry of Agriculture Awka, Nigeria. The capacity based machinery size
selection will assist in decision making on tillage implement selection model; including comparison of machinery
alternatives within and across various power sources. A plough capacity of 0.8956 hectare per hour which translates
to 2.5997 m was predicted for processing the 675 ha farm simulated by the developed model. This capacity was
considered adequate when compared with the lower 1.8385 m width required on the basis of available suitable field
operation period. The smallest plough width of 1.7587 m predicted by the Hunt-Wilson model was seen as less than
adequate. Finally based on the pieces of equipment available readily in the local market, 3 pieces of 0.310 hectare
per hour was chosen to provide the needed plough capacity. Their combined capacity of 0.930 hectare per hour
translates to a width of 2.999 m. The corresponding annual machinery cost per hectare was predicted as N5,542.72
