At Four Oaks Farm in north Topeka, we take optimum nutrition, climate change and sustainable living seriously. We're not just talking about extreme weather, climate change and health, we're doing something about the truly huge challenges facing us all. So, we convert biomass into charcoal ("biochar") to add to soils to grow high quality "nutrient-dense" food that's "carbon-negative."
Thus, we sequester carbon out of the air into soil to grow crops with superior health and foods with superior nutrition, whle we make our small contribution to reverse climate change. Just one of many ways we are preparing for our impending shift to a sustainable society. We're exploring farming methods, food production systems, quality standards, cooking methods, and eating habits that are the foundation of sustainable communities and culture in the 21st Century.
We invite you to join us, as we learn, practice and build this new way of life. Bring your family. Bring your curiousity and enthusiasm to meet new people, learn new ways to live, eat and heat. Our commitment is to demonstrate and teach truly 21st Century ways of living on the Earth and in nature.
Four Oaks Farmer
"Are we having fun yet?"
Eventually, a biochar-making burner will heat our 40x100-foot greenhouse to permit a 12-month growing season, and provide on-farm energy and fuels. One goal to reduce our carbon footprint is to produce and consume more of our food locally, and minimize transportation, packaging, storage, fertilizers, and other fossil-fueled processes. Another goal is to cut health care costs by assuring our families eat the freshest, best tasting, most nutritious food science and love can grow.
"TLUD" means "Top-Lit Up-Draft", a new controlled combustion technology to gasify biomass. A container is filled with nicely packed biomass—in our case, smaller stems out of a brushpile. Air vents are cut in the bottom of the container. A hole and chimney is installed on the top. A fire is lit evenly across the upper end of the biomass. Biomass will burn slowly from top to bottom, like a cigar.
However, a TLUD is a "gasifier." The only air to feed the fire is sucked up from the slots in the barrel bottom, and that is just enough to gasify the biomass. But carbon burns at the highest temperature, and there's not enough oxygen to ignite and burn the carbon. So, as flames descend from top to bottom, carbon is left behind unburned. Thus, a TLUD leaves a trail of charcoal above the descending fire.
|Four Oaks Farm
TLUDs are simple and cheap to fabricate, easy to operate. We'll use our TLUD to burn the brushpile into biochar for a spring garden. We'll also test a TLUD to turn leaves into biochar, but leaves can pack too tight to allow adequate air flow. Ideally, TLUDs burn wood chips and pellets best, but until we get a chipper/shredder, we'll be breaking up brush by hand.
TLUDs with 1 and 5-gallon burners are scaled for a kitchen cookstove. Imagine a biomass burner making biochar in every kitchen in Kansas. Everyday, to cook food, each household creates a few ounces of biochar to regenerate soil, and doesn't burn fossil fuel. We'll build a few TLUD cookstoves in Four Oaks' kitchen to develop a design that's practical and functional.
Four Oaks Farmdog
There's excitement to build and use a biochar-making cob pizza oven to make fire-roasted vegetables. And on a small trailer, we can wheel it to events for live demos and fresh roasted, nutrient-dense vegetables.
Next, we'll build a nested kiln and retort with 55 and 30-gallon barrels. Instead of direct burning, biomass is sealed in an oven to bake from outside. Without air, biomass can't ignite and burn, but breaks down as temperature rises. "Pyrolysis" uses heat to cause chemical disassembly.
Initially, above 200 degrees, white water vapor boils out. Above 400 degrees, hydrogen, methane and carbon monoxide are expelled—all flammable gases. As temperature rises further, vapors and liquids are distilled out, including organic acids. Eventually, dense resins coke out, leaving only char and tar in the retort.
A retort can process a wider range of materials, allows capture instead of combustion of off-gases, and is more efficient than a TLUD. A retort burner allows us to explore producing gas and liquid biofuels on the farm, and develop a controlled combustion heater for our greenhouse. Properly installed, a heat exchanger can generate high temperature water for soil heat and other uses.
|Four Oaks Farmhouse
In soil, biochar isn't an inert ingredient, or a fertilizer, or food source. Yet, biochar transforms soil from inert chemicals into a living matrix of nutrients and biology in functional, symbiotic communities.
First, charcoal is ideal to filter water because its microscopic micropore sponge soaks up water, cations and anions. This keeps soil moist, while minimizing nutrients lost by leaching.
Then, microbes move in. They have water, food, shelter, empty space. Microbes don't eat biochar; they live in it. Long-term permanent. Properly made biochar is super-stable in soil for at least 1000 years.
Plants grow better in this living soil, are healthier, with higher nutrient levels and greater disease and pest resistance. Exactly how biochar makes plants grow better is still a mystery being investigated by science, but the nearly universal result is larger, stronger plants with far more roots.
|Rachel, Vern & Lavetta
Learning for Life Farm Team
Microbes successfully created, managed and optimized soil fertility for at least one billion years. Their service made life possible for larger life forms could evolve and live on Earth. The 21st Century Green Gevolution is this shift from chemistry to biology. Biological agriculture inoculates and enlivens these symbiotic soil food webs, and manages them to optimize these microbial functions and services, such as nitrogen fixation.
Biochar not only makes it possible to achieve this transformation of soil, agriculture and food quality. Biochar makes it easy. And it's carbon-negative, so biochar in soil lowers carbon dioxide, methane and nirous oxides in the atmosphere to reduce our perilous planetary greenhouse gases.
Four Oaks Tree Hugger
So, considering the unnaturally warm, dry winter weather, we plan on making a lot of biochar at Four Oaks Farm while we get our greenhouse ready for planting. Come on over and help sequester carbon and learn how to grow nutrient-dense, carbon-negative foods. We're making a sustainable future happen now.
Four Oaks Community Farm meetings
are the first Tuesday of every month:
|April 3, May 1, June 4,
July 3, August 7, September 4,
October 2, November 6, December 4
The next meeting on February 7 at The Learning for Life Center will begin to develop an organization, plan a month of farm workdays, discuss a financial structure, review our recent soil tests, and assemble our seed orders. Future meetings will be at Four Oaks Farm.
A Model for Urban Agriculture