Effect of Biochar and Inorganic Fertilizer in Yam (Dioscorea rotundata Poir) Production in a Forest Agroecological Zone

Abstract

Yam production is characterized by low fertilizer input and annual shifting in search for fertile lands. This practice usually leads to reduction in the yield potential of the crop and destruction of the environment. Biochar additions through its ability to improve soil fertility and increase crop yields could be used to solve these problems. This study therefore investigated the effect of biochar and inorganic fertilizer application on yam production in a forest agro ecological zone in Ghana. A 4×3 factorial experiment in a randomised complete block design with three replications was used. The treatments consisted of four application rates of wood shaving biochar (0 t ha-1, 5 t ha-1, 10 t ha-1 and 15 t ha-1) and three inorganic fertilizer rates (0-0-0 N-P2O5-K2O kg ha-1, 30-30-30 N-P2O5-K2O kg ha-1 and 60-60-60 N-P2O5-K2O kg ha-1). No significant differences in soil parameters in response to the treatment were observed, with the exception of total N, where a decline was observed for all the treatments compared to the controls after harvest. Vegetative growth parameters of yam were not significantly influenced by biochar and inorganic fertilizer application. The number of seed yams per hectare was the only yield parameter that was significantly (p=0.05) decreased by biochar application. Dry matter, production was also significantly (p=0.05) increased by fertilizer application at 24 weeks after planting and at harvest. It is suggested that aged and higher rates of biochar would efficiently support yam production.