Please note: I have a few posts about Biochar in addition to this one.

CLICK HERE to see my post about how to make your own biochar / charcoal.

CLICK HERE to see my post about putting the contents of your water filters (which typically contain biochar / charcoal) into your compost pile.

It took me a while to understand why biochar is so beneficial. At first glance, it doesn't seem like something that should be so good for your soil, but I'd been assuming biochar was the same thing as ash. But biochar has some amazing benefits ash doesn't have!

Basically, ash is what's created when wood is subjected to temperatures that are so extreme, it gets burned up to the point where that wood no longer has a structure. But biochar is the form that burnt wood holds before it turns to ash and completely crumbles into dust.

Because biochar has been able to maintain its structure (a bunch of tiny, microscopic holes), that makes it a very beneficial place for microbes to live and thrive!

Everyone wants a place where they can live and thrive, right? Well, it's the same thing for microbes as it is for humans!

All those tiny holes in biochar give the soil the ability to soak up and retain water (just enough so the soil is most but not soggy). When you are able to have good soil aeration, it can breathe, and you have healthier plants!

Image source: https://www.artofit.org/image-gallery/86553624083329191/biochar-a-brief-overview-biomass-charcoal-and-biochar-ash-and-biochar-charging-of-biochar/

This was a really helpful description, from researchgate:

https://www.researchgate.net/post/Role-BioChar-as-soil-enhancer-soil

Paul Reed Hepperly

University of Puerto Rico System

When soils are compacted as in compressed clay soil the water will not penetrate and the aeration will be poor. These conditions do not permit optimization of crop growth for most plants. The ability of soil carbon to improve water percolation into the soil and its retention and recycling is well established. The ability of carbon in the form of soil organic matter or biochar will increase the biological capacity of the soil also. As Anoop commented a major advantage of biochar is its persistence which gives long term advantage from an infrequent application. Carbon which is in the soil does not contribute to Carbon in the air and if carbon deposit outweighs decomposition the global climate change potential from greenhouse gas enrichment will be able to be reversed. Take a look at the wood material cover section when this material is pyrolyzed it created a carbon skeleton which is replete with spaces which although a great increase in porosity of the amended soil medium and increased cation and anion exchange. The honeycomb aspect allows protected sites for the development of bacterial colonies and fungal hyphae. The habitat of the biochar creates a niche and is involved in nutrition. Pyrolysis products can actively lime the soil to allow greater microbial action. I hope this slide will help you envision what we like to refer to as biochar as soil reef. A reef is the biggest productivity potential since the action of the reef is to habor beneficial flora and fauna. Researchers suggest biochar may be doing something similar in the soil as reef organisms affect marine productivity.