Evaluating the effect of site-specific soil information on farmer input choices and the relationship between poverty and soil quality in Tanzania

DESCRIPTION: Poor soil quality and the associated low crop productivity is linked to the pervasive rates of poverty and malnutrition ensnaring much of Africa. One challenge is that farmers, in particular small-scale farmers, do not know the status of their soils. Despite considerable soil variation across farmers and fields, governments generally set a single fertilizer application recommendation for a region or country. While uniform recommendations can improve yields up to a point, obtaining higher yields will require a targeted approach that makes efficient use of environmental and economic resources.

In Sub-Saharan Africa, laboratories that conduct soil tests and make recommendations are lacking, and the costs are beyond the reach of most farmers in the region. Without such soils information it is not possible to make recommendations specific to farmers’ soils and growing conditions. Given that soil quality has been shown to have an inverse relationship with farmer wealth, site-specific diagnoses and recommendations may be of particular use to poorer farmers.

Research supported by the Feed the Future Innovation Lab for Assets and Market Access will test whether better information about soil quality helps farmers apply inputs more effectively and increase yields. The project will employ a randomized control trial to evaluate how this information impacts production input decisions, yields and the welfare of farming households in the Morogoro district of Tanzania.

OUTCOMES: This study explores why farmers may not use information about soil quality to enhance production investments. The results will show how SoilDoc helps farmers in making soil management decisions, which farmers respond to the new information and to what degree, when the information is most beneficial, and links between adoption, yields and poverty. These results will help to design large-scale efforts to improve farming productivity through information about soil quality.