Effects of biochar and poultry manure on soil properties, growth, quality, and yield of cocoyam (Xanthosoma sagittifolium Schott) in degraded tropical sandy soil

Abstract

Use of biochar (B) and poultry manure (PM) as soil amendments can improve the productivity andsustainability of tropical agriculture. Our fieldwork is the first research on the agronomic use of B andPM for the growth of cocoyam in sandy soil of the humid tropics. In this study, the effects of B, PMand their mixture were investigated on soil properties, mineral and nutrient concentrations, growth,and corm and cormel yields of cocoyam during the 2017 and 2018 cropping seasons. The experimentconsisted of 4 × 2 factorial combinations of B (0, 10, 20, and 30 Mg ha−1) and PM (0 and 7.5 Mg ha−1).In both years, the application of B and PM either alone or in combination improved soil physical and chemicalproperties, plant nutritional status, growth, and corm and cormel yields of cocoyam. The combination of30 Mg ha−1 B and 7.5 Mg ha−1 PM (B30 PM7.5) gave the highest corm and cormel yields of cocoyam.Pooled over the 2 years, application of B at 30 Mg ha−1 and PM at 7.5 Mg ha−1 (B30 PM7.5) significantlyincreased corm yield of cocoyam by 47 and 66%, respectively, when compared with sole PM at 7.5 Mg ha−1and B at 30 Mg ha−1. Lowest corm and cormel yields were obtained for the unmanure control. The com-bination of 30 Mg ha−1 B and 7.5 Mg ha−1 PM is recommended for soil fertility management and cocoyamproduction in the rainforest agroecology of SW Nigeria.