Ameliorative Potential of Biocharcoal on Sodium Azide Toxicity in African Yam Bean (<i>Sphenostylis stenocarpa</i> Hochst. Ex. A. Rich) Harms.

Abstract

The study focused primarily on evaluating the ameliorative potential of biocharcoal on sodium azide toxicity (35 ppm) in African yam bean (Sphenostylis stenocarpa Hochst. Ex. A. Rich) Harms. A field experiment was conducted using river sand and mixtures of biocharcoal from Pentaclethra macrophylla, represented by 0 (100 % river sand, control), 25, 50, 75 and 100 % biocharcoal added to ameliorate the toxic effects of sodium azide on African yam bean. Morphological parameters measured include germination percentage, number of leaves and secondary roots, percentage seedling emergence, shoot height, number of branches and number of leaves were recorded. The effect of biocharcoal on the toxicity of sodium azide to soil pH, conductivity, nitrogen, phosphorus, potassium contents and microbial community were also recorded. The growth of African yam bean was significantly improved by the application of the biocharcoal as higher plant height, number of leaves, percentage seedling emergence and number of branches were observed when compared with control. Soil conductivity, potassium and phosphorus were significantly higher in the treatments with biocharcoal. No positive effect on soil nitrogen content was observed. Biocharcoal addition adversely affected soil microbial community. Biocharcoal proved to have ameliorative potential however more work is needed to understand the mechanism by which it operates.