Soil Fertility Evaluation for Coffee (Coffea arabica) in Hai and Lushoto Districts, Northern Tanzania

Abstract

The aim of this study was to evaluate the soil fertility status of selected coffee growing districts of Northern Tanzania and recommend immediate and long term soil management intervention strategies. The study was conducted in Hai and Lushoto Districts, between May and September, 2011. A total of 116 soil augerings and 10 soil profiles were described, and soil samples analyzed for the key fertility parameters. These were evaluated qualitatively by assigning scores against the requirements of Arabica coffee, and quantitatively by calculating the total soil-available nitrogen, phosphorus and potassium. Spatial assessment of the total soil-available nutrients was done using ArcView GIS 3.2 and ArcGIS 9.3. Soil fertility was found to be considerably low in the study areas, much lower in Lushoto than in Hai. Limitations common to both districts are low P and micronutrients, while the additional ones specific for Lushoto are low cation exchange capacity and exchangeable K. Spatial interpretation revealed interesting trends, which could be explained from the topography of the area and/or the farming practices common in the area. The results are discussed in this paper, and recommendations on appropriate integrated soil fertility management strategies are put forward.