Biochar is not a new concept in agronomy. For thousands of years, humans have used it to amend soils to improve water-holding capacity and fertility.
Today’s farmers, though, may also be looking to biochar to remediate other challenges around their fields and livestock facilities. Kim Slezak is a forest products specialist with the Nebraska Forest Service. She works with the Great Plains Biochar Initiative, a partnership among the NFS, Kansas Forest Service, Wilson Biochar Associates, and High Plains Biochar LLC whose purpose is to improve biochar education and market development in the Great Plains.
Here are six things Slezak says farmers should know about biochar and how it may be useful on their farms and ranches.
1. Source material matters. Biochar is charcoal produced from plant materials. Slezak says making biochar from dead woody materials from forest or pasture cleanup is ideal. It’s a way to turn that biomass into a value-added product that still sequesters carbon. Hard orsoft woods are both fine, she says, and biochar is one way to repurpose invasive eastern red cedars. She warns against making biochar from walnut trees, though, due to the allelopathic, or growth-suppressing, properties that can carry over into your crop field. There’s a reason the ground under walnut trees is so clear, she says, and that property of walnut trees isn’t exactly conducive to improving your soil fertility.
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2. It can increase soil water-holding capacity. Farmers who are concerned about stretching their available water resources might want to explore using biochar as a soil amendment. Some soils respond better than others to added biochar, Slezak says. Farmers should look to the Natural Resources Conservation Service Web Soil Survey or talk with their local NRCS office to get more advice for their individual soil needs, she advises.
3. It can reduce your fertilizer bill. The U.S. Biochar Initiative (USBI) expains that biochar captures carbon, and when it’s introduced to some soils, it can improve soil organic matter and boost the carbon cycle. In order to get the best return, though, Slezak warns that you should use “charged” or “inoculated” biochar rather than raw biochar. “Raw biochar is what you get after the initial burn,” she explains. “Charged biochar is what you get when you mix that charcoal with manure or compost and let it set for a couple of weeks before you apply it to your soils. You can even float biochar in a lagoon so it can soak up those nutrients before you apply it.”
4. Apply it at any time. Biochar can be applied any time that you would normally be doing fieldwork, Slezak says. Incorporating it into the soil is best, she says. But if you can’t do that because of no-till systems, you might consider applying it when you apply your dry fertilizer. Some people also make a slurry of extra-fine biochar and lagoon water and apply that through liquid fertilizer applications.
. You can make your own. The simplest way to make biochar at home is to use a burn pit, for the pyrolysis process, Slezak says. “You make a pile out of your wood in the pit,” she says. “Then, start a fire at the top of the pile. The heat from that fire at the top makes a cap that holds embers and gases and creates a cleaner burn. Then, just before the pile reaches the ash stage, quench the fire with either water or soil, and you have your biochar.” There are also kilns that you can make that provide more control over your pyrolysis. You can find plans at wilsonbiochar.com.
6. It’s a manure management tool. Slezak says adding a layer of biochar in cattle pens can bind manure, making it easier to remove that manure from the pen without taking too much soil with it. This combination can then be further composted or applied to fields, bringing the benefits of biochar and manure to soils.
The Great Plains Biochar Initiative will have more resources available for farmers and ranchers at nf.unl.edu/great-plains-biochar-initiative. More information is also available at the USBI site, biochar-us.org.
