Biochar as an alternative growth medium for tree seedlings in the Guinea Savanna Zone of Ghana

A good planting medium is required for raising tree seedlings in the nursery, however Guinea savanna soils are generally poor in nitrogen and organic matter. This poses a challenge in accessing fertile soil for tree nurseries in Northern Ghana. The experiment was conducted in the Nyankpala campus to explore the potential of plant biochar as growth media for raising tree seedlings. Growth media prepared from six different biochar formulations (Groundnut Husk Biochar; Rice Husk Biochar; Wood Biochar; Groundnut Husk Biochar + Soil; Rice Husk Biochar + Soil; Wood Biochar + Soil) and control (untreated topsoil) were each replicated in three seed boxes. Seed boxes were arranged in a Completely Randomized Design with 50 Khaya senegalensis seeds sown in each box. Percentage seed emergence did not vary significantly between treatments (p > 0.05) although Groundnut Husk Biochar recorded a marginally higher emergence (65.71%). Similarly, Groundnut Husk Biochar recorded a significantly higher plant height (10.23 cm) in the second week after planting (p < 0.05) as well as mean number of leaves (6.02) in the sixth week after planting (p < 0.05). In general, Groundnut Husk Biochar had the greatest effect on initial growth performance of K. senegalensis and could therefore be explored as a growth medium for raising tree seedlings in Northern Ghana.   Key words: Biochar, growth media, Khaya senegalensis, plant height, soil.