Book of Abstracts
11th IFOAM Scientific Conference
11-15 August 1996, Copenhagen, Denmark
1Tumbi Agricultural Research Institute, P.O. Box 306, Tabora Tanzania. 2Ministry of Agriculture, Department of Research and Training, P.O. Box 2066, Dar es salaam, Tanzania.
Maize is the major food crop in Tabora region of Tanzania. Soils in the region are sandy and low in nutrients. Fertilizers which most farmers cannot afford due to high prices are needed. Alley cropping has increased yields substantially in some countries in Africa. Alley cropping research in Tanzania has concentrated on Leucaena leucocephala. Species like Acacia julifera, Acacia leptocarpa and Senna siamea which are adapted to Tabora conditions have not been tested.
The objectives of this trial was to evaluate the suitability of Leucaena leucocephala, Senna siamea, Acacia julifera and Acacia leptocarpa for alley cropping under Tabora conditions. The trial was laid out on a sandy soil; Haplustalf (USDA) at Tumbi Agricultural Research Institute, Tabora, Tanzania.
The experimental design was complete randomized block with four replications. Plot size was 12m x 10m. Treatments were Leucaena leucocephala, Senna siamea, Acacia leptocarpa, Acacia julifera and a control with no trees. Trees were established in the first year of the experiment by seedlings which were planted in double rows at a spacing of 1m x 0.5m. In the second year the trees were pruned to one metre height and prunings incorporated into plots. Maize was sown plots at a spacing of 1m x 0.5m making alleys of 12m x 5m on both sides of the tree rows. At harvesting stover and maize grain was recorded.
For three consecutive cropping seasons, significant (P) differences in maize yield between treatments and the control were obtained. The order of performance was; Leucaena leucocephala Senna siamea Acacia leptocarpa Acacia julifera. Leucaena leucocephala and Senna siamea appeared suitable for alley cropping in Tabora. Due to the incidence of the leucaena psyllid (Heteropsylla cubana) which attacks Leucaena leucocephala, resistant species like Leucaene pallida and Leucaena diversifolia should be used. Acacia julifera and Acacia leptocarpa are less suitable due to their relatively poor coppicing ability.
Kang, B.T and G.F Wilson (1987): The development of Alley cropping as a promising Agroforestry Technology. In. Steppler, H.A and Nair, P.K.R. (eds). Agroforestry - a decade of development. Nairobi: ICRAF. p. 227-243.