ABSTRACT

A study was conducted in the three agro-ecological (mangrove forest, freshwater swamp forest and lowland rainforest) zones in Akwa Ibom State, Nigeria to identify the various agroforestry components of homegardens, ascertain management practices and sources of knowledge of the homegardens, obtain information on species richness, species diversity and species similarity indices of homegardens. Single-factor experiments with three replications per vegetation zone were used to study the socio-economics and ecology of homegardens in 2005 and 2006. Using multi-stage random sampling technique, 30% sampling intensity of the Local Government Areas in each agro-ecological zone in Akwa Ibom State was utilized. For socio-economic study of homegardens, well-structured (pre-tested) questionnaires were administered to 100 households per randomly selected LGA. The questionnaires involved data on income generation, fertilizer input, gender roles, source of management knowledge, impact of Agricultural Development Project/other donor agencies, component crops and animals and agroforestry practices. Closed traverse survey method was adopted to determine the area of each sample homegarden. Species richness, species diversity and species similarity indices were computed in homegardens. Fisher’s least significant difference (F-LSD) at p<0.05 was applied to separate differences between treatment means. 79.70% of the respondents were males. About 94.20% had formal education at various levels. 65.20% of respondents have practised homegardening for 21-40 years. Indigenous knowledge was the major source of knowledge of homegardens in the study areas. Female gender was the major source of labour in the management of homegardens in Akwa Ibom State. Problems of homegardens were in the following significant order: lack of improved planting stock > inadequate funds > animal pests/diseascs > land scarcity > fertilizer input > planting time > plant pests/diseases > storage facilities. Household wastes (92.70%) respondents are major the sources of soil nutrients in homegardens. Snailery is the major (p<0.05) animal production system in homegardens ofAkwa Ibom State. Household income generation in homegardens was xiv generally highest during the dry season (January - March; November - December). Lowland rainforest and mangrove forest ecosystems had significantly (p><0.05) the highest and least mean incomes generated per household respectively. Lowland rainforest ecosystem had higher time concentration index (TCI) (20.78) than similar TCI of homegardens in mangrove (9.36) and freshwater swamp forest (9.63) ecosystems. Lowland rainforest (0.95ha) and mangrove forest (0.19ha) had the highest and least homegarden sizes per household respectively in Akwa Ibom State. In 2005, the volumes oftimber ha’1 in homegardens in the three ecological zones were statistically similar. The similar timber volumes ha’1 per household of the mangrove and lowland rainforest ecosystems in 2006 were significantly greater than that of the freshwater swamp forest. 94% and 6% households practised agrosilvopastoralism and agrisilviculture respectively. In 2005 and 2006, the same number of plant species were identified and enumerated in the homegardens of mangrove forest (53), freshwater swamp forest (81) and lowland rainforest (102) ecosystems. The following species diversities indices in homegardens per vegetation zone were respectively obtained in 2005 and 2006: mangrove forest ecosystem - 1.99 and 1.89; freshwater swamp forest — 2.99 and 2.77; lowland rainforest — 3.22 and 3.62. In 2005 and 2006, the following Menhinick’s species richness indices per vegetation zone were obtained respectively: mangrove ecosystem — 1.96 and 1.76; freshwater swamp forest — 2.20 and 1.75; lowland rainforest - 2.64 and 2.21. Sorenson’s similarity indices for homegardens between vegetation zones were as follows: mangrove forest and freshwater swamp forests ecosystems — 46%; mangrove forest and lowland rainforest ecosystems - 36%; freshwater and lowland rainforest ecosystems - 65%. The number of plants ha’1 per life-form across the three vegetation zones were significantly (p><0.05) as follows: shrubs (460) > arable crops (324) > trees (178) = climbers (167) > palms (47).