Characterising Productivity Factors Affecting Maize (Zea mays) Production in a Smallholder Crop-Livestock System

Socio-economic factors can influence decisions and the intensity of management practices, which when appropriately considered could bridge yield gaps. The study aimed to investigate factors affecting maize (Zea mays L.) production in a smallholder crop-livestock system. Social and management analyses were performed to ascertain the factors influencing maize productivity using interviews and questionnaires. The study was conducted in two main maize-producing regions of Eswatini, the Highveld at Mankayane and Middleveld at Luve. Additionally, on-farm trials were established for two cropping seasons to evaluate maize response to three fertiliser regimes: cattle manure only, cattle manure plus inorganic fertiliser, and inorganic fertiliser only and lastly to determine the most economic fertiliser regime. Each fertiliser regime was replicated six times. Weed biomass and maize yield were collected from a 5 m × 1 m quadrat. Moreover, economic analysis for each fertiliser regime was performed using partial budgets comprising fertiliser and weed management costs. The social and management analyses showed that maize yield was strongly associated with household size (p < 0.05), land area cultivated (p < 0.05) and herbicide application timing (p < 0.05) indicating the effect of these factors on yield. On-farm trials revealed that the inorganic fertiliser only regime resulted in a significantly (p < 0.05) higher maize yield compared to manure only and manure plus inorganic fertiliser regimes in both study areas. Weed biomass was significantly (p < 0.05) lower in the inorganic fertiliser only regime at Mankayane compared to the manure only and manure plus inorganic fertiliser at both localities. The economic analysis showed that the manure only fertiliser regime had low costs that vary and high net benefits indicating that manure has the potential to improve soil conditions, reduce environmental impacts, and increase profits.