Maize response to applied nutrients for West African savannas

Abstract Maize ( Zea mays L.) grain production increased by 428% in Burkina Faso and 82% in Nigeria during the past 20 years primarily due to increased production area. To improve profitability, yield ha −1 needs to be increased. Yield response functions for nitrogen (N), phosphorus (P), and potassium (K) and response to a Mg–S–Zn–B (MgSZnB) treatment were determined from results of 16 studies conducted in the Sudanian and Guinean savannas in 2014 and 2015. Mean grain yield with no fertilizer applied and mean response to the economically optimum N rate (EONR) were 0.82 and 2.18 Mg ha −1 in Burkina Faso and 3.35 and 0.48 Mg ha −1 in Nigeria. There was little response to P and K. The EONR ranged from 45 to >120 kg ha −1 for Burkina Faso, with higher EONR for Luvisol compared with Ferralsol soil. The mean EONR for Nigeria was only 24 kg ha −1 . The results indicated high profit potential for N application at the EONR in Burkina Faso, but less potential in Nigeria despite higher yields. Yield increases and net return to N could be increased by 72% for financially constrained farmers by applying the same amount of fertilizer N at 50% EONR to twice as much land. Yield was increased by 36% with compost and 40% with MgSZnB application in Burkina Faso but with no effects in Nigeria. The response to MgSZnB requires further investigation in Burkina Faso to optimize nutrient‐specific responses. Inconsistent responses to P indicate a new for more research.