Neco 2018 Agricultural Science Question 5

A farmer has 2 hectares of land on which he intends to practice mixed cropping of maize and cowpea. Soil test results show that the soil currently contains 60 kg of available nitrogen (N), 20 kg of available phosphorus (P) and 30 kg of available potassium (K) per hectare. The recommended fertilizer applications per hectare are: - Maize: 120 kg N, 60 kg P₂O₅, 40 kg K₂O - Cowpea: 30 kg N (to be supplied by biological fixation), 20 kg P₂O₅, 20 kg K₂O The farmer will allocate 1.2 ha to maize and 0.8 ha to cowpea. Seed rates are 25 kg ha⁻¹ for maize and 10 kg ha⁻¹ for cowpea. Market prices are ₦150 per kg of maize and ₦200 per kg of cowpea. Fertilizer costs are ₦30 per kg of N, ₦25 per kg of P₂O₅ and ₦20 per kg of K₂O. Expected yields are 4 t ha⁻¹ for maize and 1.5 t ha⁻¹ for cowpea. No other costs are considered.