Multiple purpose tree use by farmers using indigenous knowledge in subhumid and semiarid northern Nigeria

Published online: 04 April 2012The northern Guinea savanna is generally known to be suitable for the production of annual crops of short-to-medium duration but is threatened with soil degradation because of inadequate organic inputs. Trees can be one important source of organic supplement to crop fields. Farmers' preferences for trees are related to a myriad of needs which vary in different environments. A survey was undertaken in Bauchi and Kaduna States of northern Nigeria to determine the extent of farmer knowledge in identifying niches for agroforestry trees. A total of 190 farmers were interviewed in Bauchi State and 154 farmers in Kaduna State. In Bauchi State, the preferred location for most trees was first bush fields (21 species or 64%), then compound fields (12 species or 36%), and village fields (6 species or 18%). There was more than one preferred location for some tree species. The 33 species in Bauchi State have important uses ranging from human food (42% of species), animal feed (12%), medicinal and windbreak/shading (both 9%), and live fencing and tools (both 6%). In Kaduna State important uses for a high proportion of the 12 species were medicinal and human food (both 50%), fuelwood (42%), and tools (33%) while the preferred location was in bush fields. In Kaduna State use of trees for soil improvement appeared stronger than in Bauchi State, especially with Parkia biglobosa. Descriptive and principal component analysis (PCA) further showed that in Bauchi State, compound fields are preferred for trees producing human food and shelter, while bush fields are used for trees producing animal feed and tools. In Kaduna State, trees producing food are preferred on all field types while field borders, woodlots and isolated trees were favored over hedgerows. This indigenous knowledge and preferences are essential when designing agroforestry systems in the sub-humid/semi-arid regions of northern Nigeria