This is not the first time I am hearing of it, but this concept is counterintuitive to me because it involves combustion, which I associate with carbon emissions. On our hillside we are working to regenerate quality soil on what once was a fertile, productive coffee farm. When the sun rises over what we planted this year to help prepare the soil for next year’s coffee planting, I have been considering what we need to do differently during the dry season. October is the last month of rainy season, so we are almost there. It is clear that we need all the good ideas we can find in this effort. This seems worthy of consideration:
At high applications levels, researchers found that biochar can not only soak up a lot of carbon, but also reduce the need for irrigation by almost 40%.
Biochar – the charcoal product used to enrich agricultural soil and trap carbon—may have a hidden commercial benefit for farmers: it could lock moisture in the soil and save on gallons of costly irrigation.
The coarse, black material, made by combusting wood, grass, and other organic materials under low-oxygen conditions, helps to sequester carbon in the soil. Biochar’s major benefit in this regard is that it doesn’t easily decompose, meaning it can become a reliable long-term carbon sink. Its application to farmland soils is recognized as one way to turn agriculture into a force for climate mitigation, helping it redress some of its immense emissions damage so far.
Biochar also reduces the need for fertilizer by enriching the soil, and gives soils the capacity to soak up excess water, which can cut the risk of runoff that strips vital topsoil off the land.
But while experts have been aware of these environmental benefits for some time, the researchers on the new BCG Bioenergy study say that not as much attention has been devoted to how these advantages could translate to benefits for farmers – especially considering that they’re the ones who need to be motivated to spread biochar on their land. That’s where their research comes in.
They examined several studies which explored how biochar increases the water-holding capacity in the soil: that’s a measure of how sponge-like soil is—or in other words, how much water it preserves for plants to slurp up, later on. This meta-analysis revealed that adding biochar to sandy soils, in particular, has notable benefits. They also showed that larger particles of biochar, instead of a finely-crushed medium, made soil more absorbent, partly because it makes the ground more porous and available for storing water.
Read the whole article here.