When you buy biochar, we supply you with a small pouch of inoculant powder. This is a blend of beneficial bacteria and fungi as well as a little bit of seaweed and humic acid. Following the instructions, add the powder to water and mix. Then soak your biochar in this liquid for a few minutes and apply to soil. Biochar works best when added to soil at a rate of 10-20% by volume.
Biochar is like a battery, and to get the best out of it it should be mixed with nutrients and microbes - a process known as charging (or inoculating / activating). If you were to add it ‘raw’ then it would steal nutrients from your plants for the first few months and then once it is charged it will start to give it back.
Other Ways to Activate Biochar
Many gardeners also claim to have had great success soaking the biochar in a compost tea. This is how we activated our biochar when we tested it on 4000 plants at our local plant nursery. To do this all, take your finished compost and mix it with some water. Then add your biochar and the liquid compost soak in. For optimal results, you can try adding a bit of sugar to the compost tea, and oxygenate it for 12 to 24 hours before adding the biochar. This will increase the populations of the beneficial microbes.
Biochar is like a sponge. If you don't charge it up with nutrients first, it will temporarily steal them from your soil instead.
Alternative soaks can be liquid seaweed or any other diluted organic liquid feed. You could use liquid fertiliser and water, without any microbes. However you won't get such great results as it's the microbes who produce the essential nutrients for the plant.
Another easy way to charge your biochar is to mix it at a rate of 10% to finished compost. Over about a two week period the nutrients and microbes will enter into the biochar, so the process is a little slower than those outlined above.