Land Suitability for Crop Diversification and Yield Potential of a Drained Swamp Area in NW -Tanzania

Abstract

To meet the increasing demand for food, land use planning in NW-Tanzania recently focuses on swampy valley bottoms which arc considered to have the highest production potential. Land development also aims at crop diversification for nutrition improvement and self-sufficiency. Locally drainage projects are required to enable dry-season crop production. 1be pilot project data of the Bigombo Valley Development Project are used to calculate the actual and potential lowland suitability according to the parameter method suggested by SYS et al. (l991 and 1993) for 9 different food crops. Local food crop priorities disagree strongly with the climatic suitability. Landscape and soil suitability is calculated for three different soil wetness levels. The potential land suitability for all crops is only marginal at the sub-optimal wetness level but moderate to very suitable at the optimum drainage level. When fully reclaimed, this land is very suitable for potatoes, beans and soybeans while moderately suitable for onions, green peppers, cabbage, tomatoes, sweet potatoes and maize.
The quantitative assessment of five food crops according 10 the FAO-AEZ method (FAD (919) confirms their suitability ranking except for potatoes. By relating the estimated figures to yield data for maize, the magnitude of the management factor is assessed, being similarly crucial for the crop production potential as soil wetness conditions.