To start off with this week’s discussion I want to pick up at the previous theme of biochar quality.
When standing next to your charcoal fire in your flushing garden with a nice matured steak on standby to “braai” as soon as the fire is ready, you can easily ask yourself: why can’t I use charcoal to improve my garden soil? That is if your head works like mine about soil.
First of all, you will get a reaction and it will most probably be positive when mixing charcoal with your garden soil. All the qualities that you will find in biochar, will also be present in charcoal. Christoph Steiner, a research scientist at the University of Georgia, says the difference between charcoal and biochar lies primarily in the end use. “Charcoal is a fuel, and biochar has a nonfuel use that makes carbon sequestration feasible,” he explains. “Otherwise there is no difference between charcoal carbon and biochar carbon.”
The fact that charcoal can still burn in your “braai” fire, means that there is still volatiles present in the charcoal that can have a negative impact on soil microbes and the reaction of minerals over a period of time. The total carbon content as well as the total “storing” capacity for microbes and nutrients is also lower in charcoal than in biochar.
So, when standing next to your charcoal fire, “braai” your steak to perfection on it when ready, but use biochar to mix into your soil with compost, manures, organic matter or fertilizer to build a healthy, productive soil in order to cultivate your plants to perfection.
As mentioned before, a good quality biochar will increase the water holding capacity of your soil, create a sustainable environment for microbes to multiply and minimise the loss of certain nutrients by volatilisation and leaching. But it will also stabilize imbalances in the soil profile to optimise plant growth and production.
You don’t want to compromise these and other advantages of biochar by adding an inferior product to your precious natural recourse – soil.
Hennie du Plessis (083 787 0432)