The first question we often get when discussing tree health and biochar is, “What is biochar?” The answer is simple and complex. Biochar is a form of charcoal used as a soil amendment. The answer can’t stop there. All organic materials, from fallen trees to crop residues to animal manures, and everything in between, can be fired into biochar.
Each “biochar” will have different characteristics determined by the feedstock and the firing process, which makes it great for some applications and less suitable for others. When we’re talking about tree health, we’re usually talking about wood biochar. Follow this link for a deep dive into the characteristics of many different feedstocks:
There is a strong interest in biochar as a tool for the restoration of forests and as a tool for climate change mitigation. The lessons learned by the US Forest Service can be applied to agricultural and landscape tree health.
Key Takeaways
- The US Forest Service has done the research that can be applied at any scale
- Charged biochar aids in water retention and nutrient availability
- Raw biochar, uncharged, can be used for invasives species suppression
- Choose feedstock and charging materials wisely, and ask questions
- Trees have benefits that range from wildlife habitat to buffering from wind, erosion, pests, and disease
- For tree health, choose trees that are native to your climate and soil pH
- Charged biochar stabilizes landscapes at every scale, from national forests to your backyard
Biochar in Forestry: Healing Burned Landscapes
Before a fire has the opportunity to start, the forestry service reduces fire hazard by cutting down selected trees. This creates large amounts of waste biomass, called slash. In the past, this slash was burned, decreasing air quality and forest soils while emitting carbon dioxide and other greenhouse gases.
Research by the Forest Service has found that firing this slash into biochar is more climate-friendly and has major benefits for the forest understory, tree health, and soil health.
After a fire, the remains of trees are removed and fired into biochar. That process, pyrolysis, removes carbon dioxide from the atmosphere for thousands of years. It’s stored in the high-carbon biochar. When the forest biochar is charged with organic materials and then applied to the forest floor, the benefits begin to stack up. Wood biochar is about 80% carbon. Adding charged biochar to the burned-over soil increases the water-holding capacity, which means less runoff and leaching. That means better water quality downstream.
Charged biochar added to the forest floor increases the nutrient cycle, and there is a marked increase in the abundance of understory growth.
Forest ecosystems are fragile when recovering from a fire. Biochar, charged, has immediate benefits that include:
- Improved seedling survival
- Enhanced microbial activity and nutrient retention
- Long-term carbon storage in the soil
Many methods are used to charge biochar. Nutrients and biology are added to the biochar with compost blends, manure soaking, fertilizer solutions, and humates, among other organics. Charging brings the biochar to life.
Wood biochar and humates are valuable partners in soil and tree health
The Exception to Charging Biochar: Invasives Suppression
Biochar, if applied by itself, will tie up nutrients in the soil. After a forest fire, the first vegetation to sprout are usually invasive species. Forestry experiments have found that when the nutrients are tied up for a short period of time, the invasives are stunted, and natives have a chance to overtake the unwanted vegetation.
This knowledge can be applied to an agricultural system. If you have an extreme weed problem, applying a raw biochar product, such as NAKED Char, in the fall helps control weeds that would otherwise pop up after harvest.
Biochar Lessons for Homeowners and Land Stewards for Tree Health
Forestry insights can be applied to many smaller tree health projects. Homeowners, small-scale farmers, orchardists, and urban foresters all benefit from the National Forest Service research and application strategies.
Observe Before Acting
Choose your feedstock and charging materials wisely. Not all biochars are alike in performance for specific situations. Most biochars rebalance the soil pH after disturbance by human or fire activity. Aside from conifers like pines and spruces, the majority of trees native to temperate growing zones prefer a neutral pH of 6.5-7.5. Trees are adaptable, but the more extreme the pH, either acidic or alkaline, the more issues your trees will have.
Choose What Will Grow Easily in Your Location for Better Tree Health
The lesson of invasives vs natives is also valuable for sustainable home and urban tree health. Know your soil pH and climate zone. Planting trees that are native to your area is a major win for the environment (habitat for birds, pollen for bees) and easier for you to maintain.
When planting trees, shrubs, and perennials, add charged biochar halfway up the planting hole, in the mulch layer, as a foliar amendment, or soil drench. Fall is the perfect time to apply a biochar blend to your already established trees and any new plantings. You’ll give the soil microbiology a needed home and nutrients for the long winter.
Learn how Fall Nutrient Applications Prep Soil for Spring Success
Trees as Infrastructure: Windbreaks, Parks, and Public Spaces
Agricultural lands are suffering serious erosion issues because of the removal of windbreaks that began in the 1970s and continues to this day. Trees are removed for many reasons, including:
- Poor condition or age of trees
- Conflicts with modern farming equipment and field layouts
- Lack of incentives or support for maintenance
- Perceived loss of productivity from land taken up by trees
Although they are being removed on some agricultural operations, by others they are being recognized again for their ecological and agricultural benefits. There is growing interest in reviving tree planting programs for erosion control, wildlife habitat, and microclimate regulation.
Applying charged biochar once a year supports root development and drought resilience. In agriculture, a windbreak may make the difference between crop failure and success. In an orchard setting, native trees serve as buffers for pest invasions, disease spread, and windstorms.
The Value of Trees in Urban and Park Settings
Parks, golf courses, and campuses are all more enjoyable with shade trees. Maintaining tree health in a public setting is more challenging than for a homeowner. In many cases, the soil is compacted, and there is chemical runoff from salting and roadways.
Public settings tend to have poor drainage because of compaction. The impervious cement surrounding many urban tree planting holes means water is a premium.
Of the many benefits of charged biochar, the greatest in these urban areas is its ability to retain water and add biology and nutrients to starved soil. Urban trees struggle with pollution, heat islands, limited root space, and poor soil quality.
Biochar, as a charged soil amendment, can be added as a liquid through soil injection. As a solid, a biochar blend can be used as a top dressing or mixed with mulch.
Biochar is a Solution for Tree Health from Forest to Home Landscape
The versatility of a biochar blend is what makes it a solution for tree health at all scales, from forests to home landscapes. The lessons learned from the Forest Service are applicable at the municipal and home scale. First steps in your journey to optimum tree health:
- Test your soil, pH matters
- Choose trees native to your climate and soil pH
- Use charged biochar as a soil amendment for robust tree health
Charged biochar restores fire-damaged soils by increasing carbon content, improving water retention, and rebalancing pH. While biochar doesn’t add nutrients directly, it retains nutrients and supports microbial life. These functions are critical at the forest, farm, public, and home ecosystem levels.
Biochar has been shown in forest ecosystems to extend vegetation growth by nearly a month, helping stabilize landscapes and reduce erosion. This is the same benefit a municipality or homeowner is looking for to create a resilient landscape.
High-Quality Wood Biochar Charged with Humates
We know tree health is important to our customers. We also know they want an easy-to-use product they can trust. We only source our feedstock from Yellow Southern Pine because it gives us consistent high porosity. That’s important for water retention in today’s extreme weather. It buffers tree root systems from both drought and flood.
Our biochar is charged with freshwater-sourced humates, Leonardite. It has humic, fulvic acids, and other organic acids, micronutrients, and natural bio-stimulants. It gives us a consistent nutrient profile and no potential salinity issues so we can recommend application rates with confidence. We started our business working with arborists and groundskeepers; we know trees and turf. The lessons supplied by the Forest Service aligned perfectly with what we had experienced with urban foresters.
Learn how our VITAL Blend line of products can improve your tree health at any scale
For more information on the research done by the National Forest Service on tree health, see these online publications.
Biochar | US Forest Service Research and Development
Soil restoration with biochar | US Forest Service Research and Development
Biochar as a climate change mitigation strategy | US Forest Service Research and Development
Forest-Applications-of-Biochar-–-Stanislaus-Demonstration-Site.pdf
