| Popis: |
Research information on the effects of biochar and poultry manure on the growth, yield, and concentrations of nutrients in edible portions of sweet potato is rare, as essential nutrient concentrations in crops can affect human health. The objective of this study was to examine the synergistic effects of biochar (B) and poultry manure (PM) on leaf nutrient concentrations, root storage minerals, sweet potato growth, and yield. The field experiments were conducted in the forest-savanna transition zone of southwest Nigeria at two degraded sites (Owo - site A and Obasooto - site B). The treatments each year consisted of four levels of biochar (B): 0, 10.0, 20.0 and 30.0 t ha-1 and three levels of poultry manure (PM): 0, 5.0, and 10.0 t ha-1, which were combined in a 4 × 3 factorial layouts to form a total of twelve treatments. The twelve treatments were factorially arranged in a randomized complete block design with three replications. Data collected on sweet potato leaves, storage roots, growth, and yield were analyzed over two growing seasons (2019 and 2020). The results showed that the sole application of B and PM, as well as their combined application, improved the growth, yield, and nutritional quality parameters of sweet potatoes. As B and PM applications increased from 0 to 30.0 t ha-1 and 0 to 10.0 t ha-1, respectively, leaf nutrient concentrations, root storage minerals, growth, and sweet potato yield increased. In both years, there were significant interactions of B and PM (B × PM) on all the sweet potato variables that were determined, indicating the potential of B in enhancing PM use efficiency. It was found that the highest application rate of 30.0 t ha-1 B and 10.0 t ha-1 PM gave the highest leaf nutrient concentrations, root storage minerals, growth, and yield of sweet potato at both sites. The study indicated that B in combination with PM has the potential to improve the growth, yield and nutrient content of the edible portions of sweet potato for human health in severely degraded soils. |
