SEMINAR: Soil&Water Seminar, Aug23:

The Soil&Water Seminar at 1pm on Tues, Aug 23rd will be given by Winthrop Professor Bob Gilkes. All welcome!

TITLE: “Amazonian Indian Black Earths, black carbon and a little bulldust”

ABSTRACT: Indian black earths(IBE) in the Amazon basin are small inliers of very fertile, black soils in a landscape dominated by infertile highly weathered pale coloured and red soils(mostly oxisols ,ultisols and inceptisols). Several theories have been proposed for the origin of IBE and all agree that they represent the effect of long term land management practices by pre-Colombian societies. Some workers consider that the various forms of black carbon in the IBE provide chemical, physical and microbial benefits that enabled productive agriculture on these soils. This is an attractive concept for proponents of biochar for use as a soil ameliorant and as a mechanism for sequestering atmospheric carbon.

In this talk I will examine an alternative explanation for the properties and distribution of IBE and relate it to recent work in SEE on the nature of biochar and ash created from tropical and local plant species. I will propose that IBE are a consequence of the agricultural and fishing activities of communities that adapted to the diverse soils and seasonal flooding regime of the Amazon Basin in the period ca.2400-1525BP.