Improving Maize Productivity under Rain-Fed Conditions through the Combined Use of Inorganic and Organic Fertilizer in Malawi

Integrated soil fertility management was promoted on-farm during the 2018/2019 cropping season in Thyolo, Phalombe, Mulanje and Zomba districts of southern Malawi, in purposively selected extension planning areas (EPAs). Sixty farmers, fifteen from each district were involved. Trials were established in farmers’ fields with smallholder farms as replicates and extension EPAs as blocks. The following were the treatments; Maize + 92 kg N ha-1 + 46 kg of P ha-1; Maize + 3 tons of compost manure ha-1; and Maize + 46 kg N ha-1 + 23 kg P ha-1 + 1.5 tons of compost manure. Grain yield data were collected at harvest. The data were analyzed in Genstat Discovery Edition 4 and were subjected to ANOVA at 95% level of confidence. Means were separated by the least significant difference (LSD0.05). No significant differences (>0.05) in Maize grain yields were observed between the treatment with Maize + 46 kg N ha-1 + 23 kg P ha-1 + 1.5 tons of compost manure and the treatment with Maize + 92 kg N ha-1 + 46 kg of P ha-1 in all the districts. Maize grain yields were significantly lower in plots treated with the full rate of manure (3 tons of compost manure ha-1) in Thyolo, Mulanje and Zomba district. Higher maize grain yields were registered in Phalombe (3,867-4,838 kg ha-1), followed by Thyolo (1,764-2,374 kg ha-1) and Zomba (740-1,120 kg ha-1). The trials confirmed that applying a combination of organic and inorganic fertilizer to maize, increase grain yields.