Minimizing nutrient leaching from maize production systems in northern Ghana with one-time application of...

Nutrient losses through surface runoff and leaching from agricultural lands could have negative effects on surface water and groundwater resources in northern Ghana. Nutrient management strategies that synchronize nutrient uptake with availability will increase nutrient recovery efficiency and minimize nutrient losses to the environment. From field trials conducted at three locations in northern Ghana during the 2016 and 2017 farming seasons, we evaluated the effectiveness of one-time application of multi-nutrient fertilizer briquettes in minimizing nutrient leaching losses from maize production systems. We compared six fertilization strategies: (i) farmer practice (FP); (ii) NPK fertilizer briquettes applied at the recommended N, P, and K rates (100% briquette); (iii) 75% briquette; (iv) modified farmer practice (MFP) with granular N, P, and K sources applied at the recommended rate (100% MFP); (v) 75% MFP; and (vi) Control, with no fertilizer applied. Across all locations and both seasons, maize grain yield resulting from the treatments followed this order: 100% briquette >75% briquette = 100% MFP > 75% MFP > FP > control. Concentrations of leachate N from the two briquette treatments were consistently similar to background levels throughout the sampling periods, with the FP resulting in the greatest leachate N concentrations, followed by its modifications. There were no significant treatment effects on leachate P and K concentrations. Therefore, for environmental sustainability, the one-time application of multi-nutrient fertilizer briquettes could be an ideal fertilizer management strategy for maize production in northern Ghana. In addition to the environmental benefit of decreased nutrient leaching, one-time application of multi-nutrient fertilizer briquettes could provide significant agronomic benefits of increased yields from increased nutrient retention in the soil and improved nutrient utilization by the maize plants.