Abstract:
Maize production in Ghana is limited by several factors including inadequate use of improved varieties and soil fertility amendments. Two on-farm experiments were conducted during the major and minor cropping seasons of 2017 in the Eastern and Central regions of Ghana in the semi-deciduous forest zone and coastal savannah zone respectively, to evaluate the effect of goat manure (5 t ha-1), inorganic fertilizer (NPK; 250 kg ha-1 + Urea; 125 kg ha-1) and their combination on phenology, growth and yield of three maize varieties (Omankwa, Obatanpa, Ahomatea). Also investigated using focus group discussion and questionnaire were the factors influencing the adoption of sustainable maize production practices. Net benefit for introducing each treatment was evaluated using the partial budgeting approach. Application of the different soil amendments resulted in significant variations in growth and yield parameters for all the maize varieties with seasonal effects. The sole inorganic fertilizer produced significantly (P < 0.001) higher plant growth and grain yields in the major cropping season. Application of 50% inorganic fertilizer + 50% goat manure significantly (P < 0.001) out-performed either the goat manure alone, inorganic fertilizer alone or the control for all the varieties in the minor cropping season. Omankwa out-performed Obatanpa for grain yield and net benefit in the two agro-ecological zones (AEZ). This study has ascertained the use of improved maize varieties and appropriate soil fertility management as sustainable strategies in maize production and recommends the application of 50% inorganic fertilizer + 50% goat manure for sustainable maize production in smallholder farms in both AEZs. Adoption of sustainable maize production practices is however influenced by socio-cultural, socio economic, technical and biophysical factors.
