Effects of Incorporating Biochar into the Soil Using Power Tiller and Ox-Plough

Existing knowledge about biochar is derived from trials where biochar incorporation into the soil is done by hands, a practice too tedious to scale-up to commercial levels. To enhance scalability, biochar incorporation needs to be integrated into conventional mechanised tillage systems. This study aimed at assessing the effects of incorporating biochar by power tiller and ox-plough on soil water retention, maize growth and yield. A 2 x 3 factorial experiment was conducted in a split-plot design with biochar incorporating method as a main plot factor and biochar level as subplot factor, on ferralsols of central Uganda. Incorporation methods were by power tiller and ox-plough with hand mixing in planting basins as a control, while levels of biochar were 0 and 10 t ha-1 application rates. Data was analysed using two-way ANOVAs in Minitab for significant differences among incorporation methods. Results showed that incorporating biochar by power tiller significantly increased water retention effect of biochar by 27.5% (p < 0.05), while no significant effect was observed (p ≥ 0.05) when incorporated by ox-plough, compared to hand mixing. No significant difference on growth and yield was observed (p ≥ 0.05) as a result of incorporating biochar by power tiller and ox-plough instead of hands in planting basins. These findings suggest that biochar incorporation can be scaled-up, to commercial levels, through the use of power tiller and ox-plough, without negative effects on biochar performance. It is recommended that promotion of biochar technology encompasses the use of power tillers and ox-ploughs to enhance scalability.