Effects of Biochar on the Growth of Vachellia etbaica and Faidherbia albida Planted in Tigray, Northern Ethiopia

In northern Ethiopia, considerable enrichment planting is essential to enhance the regeneration of dry forests. However, planted seedlings suffer high levels of mortality in arid climates. Biochar can enhance seedling survival and growth. Therefore, this study aimed to determine the effect of biochar (derived from Vachellia etbaica) on the survival of V. etbaica and Faidherbia albida seedlings. We planted V. etbaica and F. albida into soil treated with 1 kg of biochar per seedling and into soil without biochar (control) using a randomized complete block design. We analyzed the soil nutrients, plant growth, and plant elements. The application of biochar did not increase the nutrient levels in the soil. However, the total dry mass of V. etbaica and F. albida increased following biochar application. Moreover, the total contents of several nutrients were higher in the leaves of biochar-treated V. etbaica and leaves and roots of biochar-treated F. albida than in the controls. These results suggest that biochar can alter the chemical properties of soil, resulting in the accelerated uptake of nutrients. In conclusion, the application of biochar enhances the uptake of nutrients, thereby enhancing the growth of V. etbaica and F. albida.