Optimum Combination of Farm Enterprises among Smallholder Farmers in Umuahia Agricultural Zone, Abia State, Nigeria

Farm households in Umuahia Agricultural zone of Abia State engage in crop farming with few of such farmers combining their semi-commercial farm business with livestock enterprises most of which are poultry and non-ruminants. A representative sample of thirty farmers drawn from a sampling frame from Umuahia Zonal office of Abia State Agricultural Development Project was used to solve a gross margin maximization problem for an average farmer in the area. Results showed that one sole crop farm enterprise, two crop mixtures and two of the selected livestock enterprises should be produced to maximize gross margin in the prescribed combination. The extent to which land availability, labour use and wage rate affected gross margin was tested for sensitivity analysis; land availability when increased by 25 % resulted to 13.48 % increase in the gross margin, labour use when increased by 25 % led to an increase of N15,159.90, representing about 3.04 % of N499,229.90 obtained as the optimum gross margin while wage rate when reduced by 50 % resulted to increase of about 6.16 % in the original plan. Land I (Arable land), human labour I (land preparation and planting), human labour I (2nd weeding), human labour I (harvesting) and human labour II (feeding) were the limiting factors of production for attainment of the objective function out of the 14 resource constraints in the model. The study recommends that more arable land and labour saving technologies should be employed in farm production and also calls for