Precision Fertiliser Application and Its Economic Returns for Maize Production in Kaduna State

This study examines precision fertiliser application approaches and their economic returns compared to blanket fertiliser recommendations for maize production in Kaduna State, North West Nigeria. Blanket fertiliser recommendations applied uniformly across diverse farm soils are increasingly recognised as economically inefficient and environmentally suboptimal. Precision fertilisation based on soil testing, crop nutrient requirements, and yield-goal targeting offers the potential for improved agronomic and economic performance. This study evaluates three fertiliser management approaches over two growing seasons across 18 farmer field demonstration sites in Zaria, Kachia, and Lere local government areas: blanket NPK recommendation, soil test-based variable rate recommendation, and an omission plot-derived site-specific management approach. Soil samples from each site determine baseline fertility status. Maize grain yield, nitrogen, phosphorus, and potassium use efficiency, input cost, gross margin, and return on fertiliser investment are computed for each approach at each site. Findings reveal that site-specific fertiliser management improves nitrogen use efficiency by 32 percent and gross margin by 28 percent above blanket recommendations across sites, primarily by identifying phosphorus and potassium deficiencies that blanket N-focused recommendations miss. Sites with inherently high soil phosphorus require no phosphorus addition, generating significant input cost savings. The study concludes that precision fertiliser management delivers significantly superior economic and agronomic outcomes in Kaduna State. It recommends a soil testing service programme linked to extension advisory on site-specific recommendations.

Keywords: precision fertiliser, maize production, Kaduna State, soil testing, nutrient use efficiency.