Green manure and fodder crops accepted in Tanzanian banana cultivation
Plantains, otherwise known as cooking bananas, are an important food cropin Tanzania and require fertile soil for a good harvest. For around fourcenturies now, banana-growing land has been enriched by supplements of manurefrom cattle grazing on nearby pastures. The strongly increasing populationpressure in recent decades has led to a decrease in pastureland and,consequently, manure, causing a reduction in banana harvests. Green manurecrops such as herbaceous legumes provide a solution embraced by local farmers,writes Frederick P. Baijukya in his doctorate thesis at Wageningen University
In his research, Frederick Baijukya examined agronomical andsocio-economic aspects of the integration of leguminous plants into theagricultural system and reached some encouraging conclusions. His study beganwith making an inventory of changes in land use via geographical informationsystems, interviews with local growers and historical documentation. Inaddition, field tests involving various legume varieties were carried outtogether with farmers to determine which species were the most suitable.
Local farmers had various reasons for legume cultivation,including weed suppression, increasing harvests and improving the availabilityof cattle feed. Models were computer-designed, allowing Baijukya to proposeoptimal solutions tailor-made to the objectives of individual farmers.
As a consequence of evolutions in the agricultural system, therole of livestock has also changed. Traditional free-ranging cattle areincreasingly being replaced by dairy stock (crossed with Dutch varieties) thatstay in sheds all year round. The cattle are mostly fed food crop remains, andtheir manure is used for soil improvement.
The agricultural system inTanzaniacan be compared to the traditional farming on sandy soils in the Dutch ofDrenthe. Originally infertile, the soils here were also enriched by man inorder to become suitable for farming.
According to Baijukya, local farmers view green manure andfodder crops with favour, and there is already a large demand for legume seeds.His research has generated new practical insights that will provide solutionsfor a sustainable continuation of traditional banana cultivation inTanzania.
Research into the role of legumes in African agriculture willbe expanded within the framework of the EU project AfricaNUANCES, andBaijukyas study will be extended to eight African countries.
NOTE FOR THE EDITOR
Frederick P. Baijukya defended his thesis Adapting to change in banana-basedfarming systems of northwest Tanzania on 8 november 2004 at 16.00 atWageningen University. For more information and visual material, contact: EdwinLuijks, tel. +31 (0) 317 483915, e-mail edwin.luijks@wur.nl.Questions concerning content Dr. Nico de Ridder, e-mail Nico.deRidder@wur.nl, tel. +31 (0) 317 483073