Abstract

The choice of Neolamarckia cadamba for reforestation and agroforestry programs in Nigeria could be constrained with lack of basic knowledge on the species-management in relation to its sensitivity to water and growth on low fertile soil. Hence, growth of the species as influence by watering regimes and bamboo biochar was evaluated. Treatments involved three watering frequencies (watering thrice a week, twice a week and once a week) and five levels of biochar (0, 1, 2, 3, and 4 tons/ha) combined in a factorial arrangement. These were laid out in a randomised complete block design with five replicates. Municipal-waste compost was basally applied at 160 kg N/ha. Growth in terms of shoot length, stem girth, number of leaves, dry matter and relative growth rate were evaluated. The results showed that not significant (p ˃ 0.05) highest growth was obtained from seedlings watered thrice a week with 4 tons of biochar/ha in stem girth (10.67 mm), total dry matter (23.15 g/pot), allocated biomass in stem (7.44 g/pot), leaves (9.51 g/pot) and shoot (16.95 g/pot), shoot RGR (0.022 g/g/day) and total RGR (0.025 g/g/day). Main effect of biochar was only significant (p ≤ 0.05) at 4 tons/ha on stem girth (9.38 mm), higher than control and other rates. These results indicated that with adequate nutrient-supply from organic source like compost and proper soil-management such as biochar inclusion, N. cadamba seedlings could survive and grow well under low or high watering frequency in the range of once to three times a week (420 mm to 1260 mm rainfall/ha respectively).

Key Words: Biochar, Municipal-waste, Neolamarckia cadamba, Reforestation and Soil