News & Events

Geography colloquium: A political ecology of soil nutrient depletion in fields of African farmers

Friday, December 15, 2017, 3:30PM - 4:30PM


Matthew Turner

University of Wisconsin Madison


Guggenheim Geography room 205

1475 Central Campus Mall, CU Boulder main campus

Full title

Alternatives to sustainability science: A political ecology of soil nutrient depletion in the fields of African farmers


Assessments of the sustainability of smallholder agriculture in Africa have focused on soil fertility decline. The forms in which these scientific assessments take are shaped by disciplinary traditions, development prerogatives, and assumptions about the social “drivers” of environmental change. The dominant approach in Africa today creates nutrient budgets for land areas spanning a wide range of scales: from farmers’ fields, village territories, districts, nations and continents. After critically assessing these approaches, I present empirical work that provides an alternative understanding of the causes of soil fertility variation across village territories in western Niger. The management history, yields, and soil fertility parameters of 181 fields in two village territories were analyzed along with the characteristics of the households managing and owning them (livestock and land wealth, labor, tenure security, cropped area). I show that the heterogeneity of soil fertility is socially produced with the distribution of certain macronutrients (nitrogen and phosphorus in particular) affected differently by settlement history and contemporary differences in wealth and power. This runs counter to standard ideas of homogeneous landscapes shaped by ubiquitous population-induced scarcity and land tenure insecurity. In this case, soils provide a potent vehicle for social differentiation – the rich, through their cattle, are literally harvesting nutrients from common pastures and the fields of the poor and accumulating them on their fields. The implications of these findings for rural development and resource management are discussed.

Co-sponsored by IBS Population Program and IBS Environment and Society Program.


Free and open to the public.