700 year-old indigenous African soil enrichment technique as a climate- smart global sustainable agriculture alternative
Cornell University, USA
We will speak about the results of global study conducted by Cornell University, Sussex University, University of Accra, and Aarhus Universities has for the first-time uncovered indigenous African soil enrichment technique practiced for centuries (700 year-old) by villagers in West Africa, which converts highly weathered, infertile, carbon-poor African soil into enduringly fertile farmland with carbon-rich dark earths in climate-smart manner, could be the answer to mitigating climate change and revolutionizing farming across Africa. We will describe to the global audiences for the first time about the role of indigenous people’s knowledge (often regarded as not worthy of scientific discovery) and how indigenous soil management system in West Africa, which targeted waste deposition transforms highly weathered, nutrient- and carbon- poor tropical soils into enduringly fertile, carbon- rich black soils, hereafter “African Dark Earths”. We will demonstrate that these soils developed by indigenous people store 200–300% more organic carbon and contain 2–26 times greater pyrogenic carbon or charred carbon, not managed by many conventional best practices. Pyrogenic carbon persists much longer in soil as compared with other types of organic carbon, making it important for long-term carbon storage and soil fertility. We will also show that in contrast with the nutrient- poor and strongly acidic ( pH 4.3–5.3) original soil, African Dark Earths exhibit slightly acidic ( pH 5.6–6.4) conditions ideal for crop plant growth, 1.4–3.6 times greater cation exchange capacity, and 1.3–2.2 and 5–270 times more plant- available nitrogen and phosphorus, respectively. We will show the results of anthropological investigations which revealed that African Dark Earths make a disproportionately large contribution to total farm household food consumption (26%) and income (24%) despite its limited spatial extent in some cases only 6%b of the total area. We will show radiocarbon (14C) data showing the recent development of these soils (115–692 years before present). We will also demonstrate how African Dark Earths developed by indigenous people provide a model for improving the fertility of highly degraded soils in an environmentally and socially appropriate way, in resource- poor and food- insecure regions of the world. The method is also “climate- smart”, as these soils sequester carbon and enhance the climate- change mitigation potential of carbon- poor tropical soils.
Dawit Solomon (Ph.D.)
Senior Research Associate/ School of Integrated Plant Sciences, College of Agriculture and Life Sciences,
Cornell University, 920 Bradfield Hall, Ithaca, NY, 14853, USA, Email: firstname.lastname@example.org
Summary of international and national experience: