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Making biochar with waste woody biomass

Date: August 11, 2017

Forest restoration treatments create tons of waste that is normally burned in slash piles that damage the soil. We discuss several low-tech methods to make biochar on-site. These newer techniques prevent soil damage and biochar increases soil resilience


Forest and range soils in the western United States are in need of restoration for a variety of reasons (e.g., overgrazing, fire, health). Disposing of the woody slash after restoration cuttings has been problematic for many years, and open burning has often been the easiest method for reducing wildfire risk. However, this damages the soil, limits successful regeneration on the burn sites, and encourages invasive weeds. Creating biochar is one method to sequester carbon and improve soil water holding capacity. Using biochar also decreases the risk of wildfire and increases tree resistance to insect and disease outbreaks.
Building slash piles with larger material on the bottom helps move heat away from the mineral soil and creates more biochar.
Building slash piles with larger material on the bottom helps move heat away from the mineral soil and creates more biochar.


Although slash piles have been the preferred method for woody residue disposal, they can cause severe impacts on the underlying soil, reduce site productivity, and are often the site of invasive weeds. We offer several alternatives that produce a viable byproduct: Biochar. Biochar (like charcoal) increases the water holding capacity of the soil and increases aboveground vegetation growth. We describe how to build slash piles, use traditional kilns, small-sized kilns, and a rotary kiln to produce biochar. Excess biomass can be converted into biochar and used on-site or transported for agricultural uses. Biochar creates a new market for timber purchasers to consider when bidding on harvest units. More wide-spread use of kilns or other methods to create biochar can help lessen the future risk of wildfire and improve forest health.

Key Findings

  • Biochar can easily be made on site using a variety of low-tech methods.
  • Biochar increases soil water holding capacity and can limit the effects of insect, disease, or drought.
  • Biochar can be a revenue stream for timber purchasers.

Featured Publications

Page-Dumroese, Deborah S. ; Busse, Matt D. ; Archuleta, James G. ; McAvoy, Darren ; Roussel, Eric , 2017

Principal Investigators: 
Principal Investigators - External: 
Darren McAvoy (co-PI) - Utah State University
Eric Roussel (co-PI) - Nevada Division of Forestry
Forest Service Partners: 
Matt Busse, Pacific Southwest Station (co-PI)
Jim Archuleta, Umatilla National Forest (co-PI)
Research Location: 
NV, ID, MT, OR. Regions 1, 4, and 6.