Trees integrated with crops in time and space help nutrient cycling on farms by increasing the supply and availability of nutrient in the crop root zone and reducing nutrient losses. An analysis to determine the nutrient composition of two indigenous multipurpose shrubs (
Uvaria chamae p.
beauv and
Icacina trichantha oliv) of Akwa Ibom State, Nigeria, was conducted in the lowland rainforest agro-ecological zone. The roots and leaves of the shrubs were collected from the three agro-ecological (mangrove, freshwater swamp and lowland rainforest) zones and analysed for nutrient contents including the soils. Nitrogen content was determined using Kjeldahl method while phosphorus and potassium were determined by flame photometry method. The results indicated a great variability in the nutrient composition of the two species. Nitrogen content in the leaves and roots of
Icacina trichantha was 2.78% and 1.17% while that of
Uvaria chamae was 1.85% and 0.65% respectively. The percentage phosphorus composition in the roots of
Icacina trichantha was 0.09% while that of
Uvaria chamae was 0.07%. Whereas in the leaves sample,
Uvaria chamae had phosphorus content of 0.10%, the percentage composition of potassium in Uvaria chamae was 0.09% while
Icacina trichantha had 0.05% respectively. In the roots,
Icacina trichantha and
Uvaria chamae had 0.11% and 0.09% potassium content respectively. The two indigenous multipurpose shrubs contained essential nutrient sources for growth and high crop yield. It is therefore recommended that farmers could intercrop these species with food crops in their farmland to improved soil fertility.
Keywords: Evaluation, indigenous, multipurpose shrubs, agroforestry, Nigeria