7 ms·

Isn't soil basically just decomposed organic matter, i.e. a big carbon store? What fraction of a plant's carbon goes into the soil vs. into the air?

• masklinn 10y ago
  In most soils the carbon is eventually released by the decay process (through decompositor organisms), though some generally stays sequestered (witness terra preta for instance). Some soils like peats and taiga are strong sinks as they prevent complete decay of organic material, and thus release of the carbon (until they're burned away).
• ph0rque 10y ago
  By burying a plant, you could consciously make that fraction very close to 1. This is a way to fertilize the soil for future plants, and is called hugelkultur.
  • bunderbunder 10y ago
    Hugelkulture doesn't involve burying the plants very deeply though - I suspect that it's shallow enough that CO2 that's released during decomposition can easily make it back to the surface. Most the CO2 from fossil fuels comes from ancient bogs, where plants were prevented from decomposing for long enough that they could eventually turn into materials like coal and petroleum. In essence, they were a result of taking plant matter _out_ of the biosphere, which is sort of the opposite of hugelkultur's goal.
    • ph0rque 10y ago
      Hugelkultur is intended primarily to act as a long-term (5-20 year) fertilization and water absorption mechanism, so that other plants planted on top of the mound grow better. In that context, you will have a net-positive CO2 absorption (or, a net-negative CO2 release into the atmosphere).