Biochar, a product of burning a lot of wood at very high temperatures, helps produce nutrients for garden and house plants and field crops.
It looks like charcoal but biochar isn't for cooking up burgers on the grill. It is a fire produced product that helps soil become much more productive. And it lasts a long, long time.
Trisha Jackson, a Pratt Community College physical science instructor, makes biochar and shared its uses with members of the Master Gardeners at a "Lunch and Learn" session at the Pratt County Extension Office on Jan. 17.
Biochar is a product of burning wood at very high temperatures then drowning it with water before it becomes ash. The final product is very light weight, can absorb a lot of water, makes fertilizer go further and helps soil become much more productive, Jackson said.
It can be used to improve soil quality by producing nutrients from microorganisms. It can draw nutrients from compost, food scraps and even old pottery shards. It even works with manure. In fact, the more biochar mixed with manure, the more it draws out the nitrogen and the less and less the odor until it finally disappears. The effect is immediate.
Biochar feeds soil constantly and can be used in fields, gardens, house plants with equal success. Plants respond at different rates but the change is dramatic. It helps fertilizer go further and improves sandy soil because it holds the moisture.
Biochar can even be used to clean out ponds. Just put it in a jute bag, throw it in a pond and ti will clean the pond. It's even safe to use with fish.
While other soil additives have to be renewed every year, biochar, if done correctly, will last for thousands of years. A five to 10 percent mixture is the optimum level and will last for generations.
Because biochar is so efficient, it doesn't take much to get the job done. A handful of biochar can cover an entire football field.
There are couple of methods to produce biochar. Dig a pit, Jackson's was four feet deep, have lots and lots of wood ready to burn then start a fire at the bottom and keep feeding it wood.
"I think the pit method is best for soil amendment," Jackson said.
Another method is to burn above ground and start with a large pile of wood and let it burn down. This produces a very hot fire and flames can get higher than a two story house so plan accordingly. If someone lives in town, they can make biochar using a backyard fire pit.
Whatever way is used, temperature is critical to make good biochar, Jackson said.
In the pit method, start the fire and add an abundance of wood until the fire begins to smoke. Hold off on adding more wood until the flame catches up then add more wood. Repeat this process until the wood is burned down and the fire is a deep orange-red color. This is a critical moment in making biochar. The fire needs to be above 500 degrees and the color of the fire is the indicator it is the right temperature.
Almost any wood will work to make biochar but it is critical that the wood is very, very dry. Most wood in Pratt County will make good biochar. But it doesn't have to be just regular wood. Bamboo works very well and even corn husks. Trees that have been cut down because of pine beetles are also very good for biochar.
Pieces need to be about three inches in diameter for maximum quality. Wood contains gases and in this process, once the fire gets going, it doesn't need oxygen because the fire releases the gases and the fuels the fire.
Although biochar resembles coal that is used in grills, that type of charcoal doesn't have the protein levels of biochar.
Once the wood, and it takes a lot of it, is burned down and the color is correct, drown the fire with lots of water to set the characteristics of the fire. This stops the burning process at the coal stage.
If the process is done correctly, adding biochar to soil will help produce "happy soil organisms."