Recently, the people of Minneapolis have taken it upon themselves to start improving the environment with biochar. The city was looking for a way to address many different urban challenges it was facing. Some of these challenges include improving health in minority communities, improving storm damage in the urban canopy, and decreasing disparity in access to locally grown foods. Minneapolis’s proposal was to purchase biochar as part of its environmental initiative. From research, they knew biochar is a powerful soil amendment so they wanted to test it for themselves.
After the proposal, the city moved forward with its plans. They established demonstration plots where one plot had no treatment, one plot had compost, and the last had compost and biochar. These plots were on the Mdewakanton Sioux land and in the Minneapolis urban core. After results were measured, it was clear which plot was the winner (see left). There is really no denying the incredible powers of biochar in the soil.
The City of Minneapolis has taken its use of biochar further by setting up five demonstration gardens to show the benefits of biochar in agricultural throughout the city. Each of the five gardens has a unique area of interest but all are setup to see how biochar can support a more productive crop.
To learn more about the five demonstration gardens visit Minneapolis.gov.
For more on the coordination with the Sioux Community gardens download this pdf report.
Urban scholar says
Biochar is touted as a carbon zero and sequestering carbon from the atmosphere. What is biochar, char sound familiar? Think charcoal. Yes biochar is another form of the material used to cook with. The manufacturing go biochar takes a great deal of energy to the get the process started. It eventually becomes exothermic, generates heat, but unless that heat is captured and return to the thermal manufacturing process the production of biochar generates carbon dioxide. The process of manufacturing results in the the existing carbon in the cellulose material to become slow released to the soil it is blended with. The organic decomposition is slowed down. Biochar does not collect carbon dioxide from the atmosphere. Biochar is not manufactured in your local community but out state and moved by diesel trucks to you. The manufacturing can use waste wood and other cellulose products or new timber. Either raw material is removing that material from other uses it may have been earmarked for previously such as wood much, pulp for the paper industry and biofuel plants to list just three general uses that previously existed. As soil amenity it is good to then soils that are thick and heavy that have poor drainage similar to how verimiculite has been used in the past. As a a material that promotes plant growth it s providing nutrients to plants for healthy growth as existing plant food and fertilizers do. What is not being shown is the forth plot of composted soil with require fertilizer. The effects produce greater yield as the fertilizer can be manufactured to supplement the what they native soil and compost are lacking.
Tony Marrero says
Quite a few things to consider in your post. Mostly, you have a lot of misconceptions about biochar.
Biochar truly is not like charcoal (see our post on The Difference Between Burning And Charring Biomass. There Is A Difference.)
Biochar can take a lot of energy to manufacturer but many kilns are returning the gases back into their kilns with a gasifier to make the process as efficient as possible.
Using biochar does not slowly release carbon into the soil. The biochar is made of carbon and will stay in the soil a long time. It retains water and creates a tidy home for micro-organisms to live and help natural processes return organic life to the soil.
It is true that biochar doesn’t collect carbon dioxide from the air. The removal of fallen trees and other biomass that would’ve decomposed and created more carbon dioxide is how we reduce the CO2 in the atmosphere.
The raw materials used for biochar are usually the waste materials from agricultural farming (i.e. corn stover) or cleared lumber. I’ve not heard of manufacturers that remove trees from a forest just to create biochar.
Adding fertilizer can be beneficial to soil. With patience, just adding biochar to the soil will slowly return it to a healthy environment for plants to thrive. Using fertilizer would be a quick jolt for that kind of growth but is not a long term benefit to soil as it typically needs to be replaced each season. Biochar reduces the need for fertilizer and fosters a more organic soil composition.