Testing innovations through multisite trials to bridge the gap between research and real-world farming in Northern Ghana

Maize yield optimisation requires a dual-pronged approach: improve variety selection to leverage genetic potential and precision fertilisation to address nutrient deficiencies. A simplified fertiliser recommendation framework, expressed in bags per unit area, bridges the knowledge gap between scientific guidelines and farmer application. However, this affects the rate of nutrients applied per area because of availability and farmers’ preferred fertiliser types. This study examined the disparity between recommended fertiliser rates and farmer practices to determine the impact on maize varieties. The study combined four recommended fertiliser rates (NP2O5K2O ha-1) – 100-40-40 (T1), 100-60-60 (T2), 83.75-25-12.5 + 37.5S+ 5Mg + 0.75Zn (T3) and T3 + 2.5Zn (T4) with three maize varieties – two hybrids (SC719 and Wang-Basig) and an OPV (Sanzal-Sima). A multi-site study was conducted in Ghana, encompassing 12 locations: six in the Upper West Region, five in the Northern Region, and one in the Savannah Region. The fertiliser treatments showed minimal differences in growth parameters, with isolated significant effects observed for plant height (T2 > T1 at week eight) and leaf area (T3 > T1 at week four). However, grain yield was substantially improved in T2, T3, and T4 relative to T1, with no treatment differences within these T2, T3 and T4. Yield and economic optimisation were achieved with T4, T2, and T3 for SC719, Sanzal-Sima, and Wang-Basig, with yields of 4694.7 kg/ha, 4653.4 kg/ha, and 4077.9 kg/ha. SC719 outperformed Wang-Basig in growth, yield and profitability but not Sanzal-Sima. Wang-Basig and Sanzal-Sima had comparable yields. The findings demonstrate the substantial contribution of zinc to maize productivity and profitability, as evidenced in T4. Optimum zinc application emerges as a critical factor in maximising maize production efficiency. The findings also underscore the need for a suitable local hybrid and a site-specific fertiliser recommended for agroecology. The study recommends T4 and SC719 as the best combination to boost maize productivity in the Guinea Savannah zone. By validating the effectiveness of these combinations across diverse soils and conditions, the trials identified farmer-preferred options alongside research-based recommendations. The multisite trials, therefore, generate evidence for developing site-specific fertiliser and variety advisories, providing a foundation for advisory services that move beyond blanket recommendations and align with national commitments.

Amankwaa-Yeboah, P.; Ofosu-Ampong, K.; Masoud, J.; Jizorkuwie, A.B.; Wilson, M.; Ampadu-Boakye, T.; Abera, W.