Biochar, 5 Ways We Can Utilize It


Biochar is a relatively new, yet old topic in gardening and permaculture communities. It is described by the USDA North West hub as such, “Biochar is a stable solid, rich in carbon that is made from organic waste material or biomass that is partially combusted in the presence of limited oxygen”. Biochar was arguably talked about a little too much in certain permaculture circles and a bit overhyped in the abilities it is able to perform in an environment. I will be the first to admit that biochar has a lot of crazy benefits, but it is by no means a magical cure for all of the issues which plague our land.

My first introduction to the topic of biochar occurred when I was in college. I was taking a permaculture design course and was introduced to the topic. I recall learning a lot about the benefits of biochar, but I do not recall learning about the limitations of biochar. Within the course I was fortunate enough to take in college I was granted the opportunity to make biochar via the trench method. I do not recall exactly how the method worked, but I do remember shoveling some dirt or material from one part of the trench to another.  

One of the reasons why various permaculture groups fell in love with the idea of biochar is partly due to the observed use of biochar in the Amazon by indigenous peoples and the realized benefits of their efforts. This observation lead permaculture groups to take initiative to bring that practice to their own homestead or eco-community for added potential benefits. Biochar is known to help improve soil health, raise soil pH, remove toxins from soil, improve soil moisture, and aid in soil sequestration which is a big deal now regarding climate change mitigation/suppression.

Despite my prior introduction to the use and creation of biochar, I still feel like I know very little in regards to the purpose and ideal application of the material in regards to soil conservation and overall land management. I hope to teach you what I have learned about the subject and possibly encourage appropriate use of the material in your personal landscape (depending on where you are reading this).

1. Improving Soil Health

Before moving on any further I do need to address the fact that the study of biochar and its impacts on the soil is not a complete consensus as of 2024, there is no true certainty in regards to the impacts of biochar amendments made on non-tropical agriculture based landscapes. Despite this information (or lack thereof) I do encourage everyone reading this blog do their own research and try to look into the latest information being put out on the subject.

It does not take a genius to understand that the addition of organic matter to the soil will typically improve the soil overtime. The various benefits of biochar can really help improve soil over time. Even though many people argue that biochar mainly shows its benefits in tropical soils, there is still new and emerging information showing the benefits of biochar in temperate locations. Based on the research I have looked into it may be beneficial to compare different variables of the biochar used in various regions. Some people argue that the size, shape, material composition, and temperature at which biochar is made can impact the benefits of the additive to the soil. Many of these ideas/concepts are relatively new and needs more research to show a clearer consensus.

Given the apparent benefit of biochar in the tropics it would be shocking if there was no real advantage of biochar application when observed/applied over a long time frame. A good example of the powers of biochar in the tropics is the terra preta do índio which translates from Portuguese as black soil of the Indians. It was discovered in the Amazon basin. Do note that the addition of biochar in of itself is not to be associated with fertilizer as it does not bring fertility on its own. It is the promotion of soil microbial diversity which creates fertility.

2. Raising Soil pH

You may be wondering how charcoal can alter the acidity of soil. The truth is that charcoal is naturally alkaline; the pH of charcoal varies depending on the material that the charcoal was created from. Typically charcoal tends to be on in the neutral or alkaline side of the pH scale with some exceptions. A similar example of this phenomenon is the use of wood ash for nixtamalizing corn rather than lye or calcium hydroxide (pickling lime) due to its alkaline pH.

In regards to the soil and nutrition it should be noted that in acidic and/or alkaline soils, the amount/types of nutrients available are different. This is due to the concept known as stoichiometry. This is why biochar is great in tropical environments as the soil is typically acidic. The addition of biochar/charcoal to the soil most likely neutralized the soil and freed up many nutrients for plant use. Many soils in temperate areas are already relatively neutral pH or alkaline the addition of biochar to the soil may be negligible in regards to pH.

3. Detoxing Land

Besides promoting fertility to the land, the addition of biochar/charcoal to the soil is known to help removing toxic materials such as heavy metals, pesticide/herbicide, etc. from the land. One of the scientific articles written by Fasih Haider et al. titled, “Biochar application for remediation of organic toxic pollutants in soils; an update”, which adds to the explanation of how biochar can interact with some of these soil contaiminants when they write, “…an antibiotic (sulfamethazine), a persistent hydrocarbon (phenanthrene), and a herbicide (isoproturon) were leached using wood-derived biochar, and the sorption results suggested that the addition of 5% biochar added to soil increased the partitioning coefficient factors by 20 for both isoproturon and sulfamethazine, and 2 for phenanthrene respectively (Yuan et al., 2019). Because of the graphitic and semiquinone structures, that may collect and donate electrons as well as free radicals created during the biochar synthesis process, biochar can stimulate the breakdown and redox reactions of organic molecules. P-nitrophenol, diethylphthalate, and 2-chlorobiphenyl can all be degraded by the free radical (Lan et al., 2022)”.

For those non-science folks, the main idea of this citation is that with the added 5% of biochar into the topsoil increased the rate at which a lot of these chemical pollutants breakdown since many already occurring, natural decomposition processes struggle to breakdown modern contaminants. Biochar is good at this due to the chemical composition of it and its ability to interact chemically with its surroundings. This is good and helps reduce the uptake of these chemicals by plants over time.

4. Improving Soil Moisture

Another great benefit of adding biochar to the soil is that it is able to hold water in the soil. This is important because it reduces the amount of water needed during times of drought and could help prevent further strain on our already limited freshwater supply above ground and in local aquifers/springs. Biochar does a good job at holding water due to the natural porosity and surface area though these variables tend to vary depending on the type of material the biochar is from.

From a gardening perspective it makes sense. All that charcoal really is at its core level is just burnt mulch to put in laymen terms. The use of mulch, especially wood mulch is already very common in backyard gardens/permaculture designs due to the added water holding capabilities and added weed suppression.

5. Carbon Sequestration

By now you are probably thinking that biochar is too good to be true and wonder why large scale growers haven’t given biochar a shot. I am right there with you! Lastly, one of the greatest benefits of biochar is its ability to sequester carbon. This is done by using current woody materials ad transforming them to a charcoal state. This makes them biologically unavailable and able to stay in the soil for hundreds of years. This is why in the Amazon you can still find some of these sites where indigenous people were using these methods.

If the same woody plant were to die and breakdown naturally it would usually off gas carbon dioxide which would have to be ingested by another plant. This is usually mitigated by the biochar process and puts the carbon back in the soil for a long time. It is basically a carbon bank/sink.


As I said in the introduction, biochar is one of those topics that is both new and old. The use of the additive has been noted to have occurred thousands of years ago, but only until recently has this idea been encouraged in modern agricultural practices. I understand why many producers are hesitant to jump in on the wagon due to the lack of scientific consensus for biochar use in various regions. I am confident that as time and research goes on; the benefits will begin to show itself regardless of region.

If you are able to learn to make charcoal or biochar on your own I deeply encourage you to do so. The process is not difficult and can save you a lot of money if you grill or would like to amend your own soil as to experiment with the wonderful material. I hope you learned something interesting and are excited for the future as I am.

Works Cited

“Biochar.” Biochar | USDA Climate Hubs, USDA, Accessed 4 June 2024.

Haider, Fasih, et al. “Biochar Application for Remediation of Organic Toxic Pollutants in Contaminated Soils; an Update.” Ecotoxicology and Environmental Safety, Academic Press, 28 Nov. 2022,

Leave a Comment

Your email address will not be published. Required fields are marked *