Week-end Wrap – Political Economy – August 6, 2023
Amazon dark earth boosts tree growth as much as sixfold (press release)
[Sao Paulo Research Foundation, via Naked Capitalism 8-2-2023]
The researchers found the microbiota (bacteria, archaea, fungi and other microorganisms) in ADE to be highly beneficial to plant growth. Addition of ADE to the soil boosted the growth of the three tree species they analyzed. Seedlings of Brazilian cedarwood (Cedrela fissilis) and Yellow poinciana (Peltophorum dubium) grew to between twice and five times normal height in soil with 20% ADE, and three to six times with 100% ADE, compared with growth in control soil. Ambay pumpwood (Cecropia pachystachya) did not grow at all in control soil (soil without ADE) but flourished in 100% ADE.
The dry mass of Brachiaria forage grass increased more than threefold in soil with 20% ADE compared with control soil, and by more than a factor of eight in 100% ADE.
“The bacteria in ADE convert certain molecules in the soil into substances that can be absorbed by plants. Using a very rudimentary analogy, you could say the bacteria act as miniature ‘chefs’ by transforming substances that can’t be ‘digested’ by plants into substances they can profitably metabolize,” said Anderson Santos de Freitas, first author of the article. He is a PhD candidate at CENA-USP and co-author of the podcast Biotec em Pauta.