Integrated Soil Fertility Management: Impact of Mucuna and Tithonia Biomass on Tomato (Lycopersicon esculentum L.) Performance in Smallholder Farming Systems
Many views, paradigms and concepts have been advocated in recent decades on soil fertility and soil conservation across the globe in order to provide sustainable solutions to the rising food and nutrition insecurity while preserving the natural resource base. Meanwhile, food and nutrition security in Sub-Saharan Africa (SSA) is mainly achieved through smallholder farming systems that are characterized by poor and declining soil fertility, which often leads to low crop yields and low income. Hence, a field trial was established to evaluate the impact of integrated soil fertility management (ISFM) practices on tomato yield and the farm-scale income in smallholder farming systems. The ISFM trial comprised a control with no input, mineral fertilizer, and organic treatments comprising sole Mucuna and Tithonia biomasses as well as their combination (Mucuna + Tithonia). Generally, tomato performance was better with organic plant biomass amendments, with significantly higher (P < 0.001) tomato yield for Mucuna + Tithonia and sole Tithonia, followed by sole Mucuna and mineral fertilizer compared to the control. Meanwhile in comparison to the control, Mucuna + Tithonia and sole Tithonia recorded 3.5 and 3.4 t ha−1 more yield, respectively, which was about twice the additional yield for sole Mucuna and mineral fertilizer with 1.8 and 1.5 t ha−1, respectively (Tukey’s HSD, P < 0.05). Similarly, the farm-scale income increased significantly (P < 0.001) for organic plant biomass, and it was most pronounced for Mucuna + Tithonia and sole Tithonia, followed by sole Mucuna and mineral fertilizer, as compared to the control (Tukey’s HSD, P <0.05). A positive Spearman Rank Correlation was recorded between the ISFM treatments and tomato yield or the farm-scale income (r = 0.76, P < 0.05), and between tomato yield and the farmscale income (r = 0.99, P < 0.05). These results imply that smallholder farmers in SSA can effectively use the combination of Mucuna + Tithonia biomass materials or their sole applications as basal mulch to improve tomato production. Thus, these organic amendments could be an alternative and sustainable integrated soil fertility management strategy to boost tomato production and farm-scale income without jeopardizing the sustainability of the environment. However, this requires more efforts to adapt the different ISFM techniques to the specific needs of smallholder farmers, coupled with effective dissemination strategies that facilitate knowledge transfer and technology adoption.