Land Evaluation And Suitability Assessment For Crops Produced In Butuguri Area, Butiama District In Mara Region, Tanzania

ABSTRACT

Land evaluation was conducted in Butuguri area, Butiama District, Mara Region to assess land’s suitability for cassava, maize and sorghum production. After reviewing literature and discussing with farmers and extension officers, five criteria for growing crops were selected which are: soil physical properties, soil chemical fertility, rainfall, temperature and topography. The Analytical Hierarchical Process was used to assign relative importance weights to the chosen criteria. Spatial information regarding the selected criteria were generated. Soil information was obtained by combining transects and free soil surveys after the preparation and confirmation of the base map. Climatic data were obtained from WorldClim and topographic data using Digital Elevation Map image (DEM). Seven soil units were mapped in Geographical Information System (GIS) after field and laboratory works. Soils were classified to four USDA soil orders: Inceptisols, Entisols, Alfisols and Mollisols. They were further classified to seven subgroups: Entic Haplustolls, Oxyaquic Haplustepts, Typic Kandiustalfs, Humic Dystrustepts, Typic Dystrustepts, Typic Ustipsamments and Vermic Ustorthents. In World Reference Base (WRB), soils were grouped into five Reference Soil Groups: Chernozems, Cambisols, Umburisols, Leptosols and Regosols and further classified into seven groups: Fractic Chernic Phaeozems (Colluvic, Novic), Ferralic Dolomitic Cambisols (Arenic, Aric), Cambic Acric Umbrisol (Arenic, Pachic), Skeletic Andic Cambisol (Aric, Ferric), Andic, Fragic Cambisol (Alcalic, Arenic), Gleyic Technic Leptosol (Arenic, Aric) and Brunic, Leptic Regosol (Arenic, Aric). Climate spatial information showed that the area has average temperature ranging between 21.1 oC and 22.2 oC, and annual rainfall ranging between 930 and 1160 mm. Topography spatial data showed the level, sloping to mountainous lands. The assigned weights indicated that soil’s physical and chemical fertility were the most important attributes for growing cassava and sorghum, while rainfall was the most important factor for growing maize. The resulting suitability maps established indicated that soil physical and chemical properties were the most limiting for production of the three crops, although rainfall, temperature and topography were the least limiting.