Indigenous African soil enrichment as a climatesmart sustainable agriculture alternative

© The Ecological Society of America www.frontiersinecology.org D some improvement in environmental outcomes, conventional agriculture continues to contribute to biodiversity loss, climate change, and the degradation of terrestrial and freshwater systems (Foley et al. 2011 ). A major global challenge is to develop sustainable, “climatesmart” agricultural systems that feed growing populations and adapt to climate change while maintaining lower carbon footprints and staying within critical ecological thresholds (Lal 2010 ; FAO 2011 ). Nowhere are these challenges greater than in subSaharan Africa (SSA), where agriculture supports the livelihoods of 750 million people and where average grain yields are the lowest of any region in the world (Conway and Toenniessen 2003 ). Most smallholder farmers in SSA practice lowinput subsistence agriculture and face a wide array of biophysical and climaterelated production constraints. To increase agriculture production and food security – while also contributing to climatechange mitigation – innovative, climatesmart soilmanagement practices must be developed to improve soil fertility. At present, such sustainable agricultural management strategies and models are largely lacking. One widely proposed approach is to recreate conditions that led to the formation of Amazonian Dark Earths (ADE), a legacy of preColumbian indigenous people in South America that has no known current analogs (Glaser and Birk 2012 ). Recorded use of these soils dates as far back as 5000 years before present (BP), with the majority forming between 1000–2000 years BP (Whitehead et al. 2010 ), yet they still aid in the sustainable intensification of smallholder agriculture. However, it remains unclear whether ADE were created deliberately for agriculture, or were merely a byproduct of settlement patterns and associated domestic activity; it is also uncertain whether it would be appropriate to replicate the use of such soils in contemporary Africa. In this multidisciplinary exploration in SSA, we examine the existence of indigenous soil enrichment practices capable of improving the fertility and carbonstorage capacity of highly degraded soils, and consider the potential that such anthropogenic soils have for mitigating climate change, improving livelihoods, and fostering resilience in the local population. RESEARCH COMMUNICATIONS RESEARCH COMMUNICATIONS