Biochars are charcoal-like solid materials with varied characteristics (there is not a uniform biochar product) that can be added to soil to improve soil health. Biochars can also be produced and used for other purposes like container production, water filtration, or in concrete and drywall. Biochar application as a soil amendment is one practice that can be implemented as part of a soil health management plan or conservation plan. Biochars can enhance the carbon sequestration and soil function impact of other soil health practices, like cover cropping and compost amendments. Applying biochars can improve your soil health by increasing soil organic matter, adjusting soil pH, supplying and conserving nutrients, improving soil water dynamics, and supporting soil biological function.  

Biochars are made by heating biomass (e.g. wood, manure, crop residues, solid waste, etc.) in high temperature, low or limited oxygen conditions, often in specially-designed furnaces or kilns. This thermochemical process is called pyrolysis. The feedstocks and pyrolysis parameters (temperature, oxidation, and residence time) impact the properties of the final biochar product, like the ash content, stability, and particle size. The final properties of biochars, like total carbon, stability of the carbon, nutrient content, and pH, impact how biochars react in soils. Post-production treatments, like steam activation, combining with synthetic fertilizers, mixing with manure or compost, or other chemical or physical treatments, can also change biochars’ reactivity in soils. A complete biochar analysis, which includes the properties listed above, should be obtained from the appropriate biochar producer (refer to the Biochar Suppliers Map) prior to designing the biochar application plan.  

Biochars add carbon to soil that is stable for 100s to 1000s of years and can be one natural solution for sequestering carbon and mitigating climate change. Biochars also improve soil water holding capacity and infiltration, soil structure, soil health, and crop yield. Biochars also enhance plant growth which, in turn, absorbs more carbon dioxide from the atmosphere. Quantification methods for estimating the potential of biochar applications in agriculture, and in other industries, for mitigating greenhouse gases are being refined.  

Biochars also provide economic benefits in agriculture systems by reducing fertilizer requirements, irrigation water requirements, and increasing crop yield. Estimates of economic impact will vary by operation, the cost of biochar application, and financial assistance level. As biochar markets and financial assistance programs continue to evolve, better economic analyses will be available.  

Finally, biochar production results in byproducts that may be used as renewable fuels. Pyrolysis of organic waste materials/biomass can produce liquid and gaseous products as well as biochars. Those biooils and biofuels can be used by agriculture operations and other sectors of the economy.  

Biochars can be added to soil as a stable carbon amendment through multiple processes. Biochars can be applied in cropping systems to the soil surface and incorporated like other soil amendments, or they can be banded or injected, depending on the physical properties of the biochars. In perennial systems, like vineyards or orchards, or in container production, biochars can be applied with minimal incorporation or as part of a soil media mixture. The right application method is dependent on the physical properties and qualities of the biochar, which vary widely depending on the feedstock and pyrolysis process that was used to produce the biochar as well as any post-production treatment, and the production system.  

Managing biochar applications for soil health and carbon sequestration requires matching the right biochar with the right soil at the right rate for the right purpose. You can work with a conservation professional to assess your soils, identify resource concerns, and develop a conservation plan to improve soil health and the resources on your land. If there is an existing resource concern that can be addressed through biochar application, the conservation professional you work with will help you decide which biochars and application methods are best for your soils and concerns. You can also use biochar decision support tools to select the best type of biochar and amendment rates for your soil. 

Applying biochars with compost, manure or other amendments can ease application and reduce erosion risk by increasing the weight and moisture content of total amendment. An increase in weight and moisture can also reduce the risk of wind loss, especially when applying fine grained biochar. Best management practices include moistening the material before crushing it to reduce dust created during the process, and/or crushing the biochars inside closed bags. Mixing biochars with compost or manure will add moisture to the amendment mix and aid handling and application. Personal protective equipment should be considered when applying biochars to reduce exposure to dust sized particles. 

Recent research confirms that long-term annual biochar application (for longer than 4 years) provides sustained benefits that align with the goals of building resilience, and productivity through soil health management. When matched to the right soils and feedstocks applied at the right rates and time, biochar can improve crop yield and consistency, enhance water holding capacity and infiltration, strengthen soil structure and biological function, and sequester carbon and support growing solutions and resilience to our changing climate. Applying biochar at intervals of several years is seen to have greater benefits than larger one-time applications, which can see diminishing of benefits over time due to the biochar’s aging and changing properties, as well as reduction of some of biochar’s carbon content over time. Benefits of continued application make biochar a valuable addition to soil health management plans, combined systematically with other practices like cover cropping and compost application. 

Outcomes support the use of biochar as a natural climate solution and a key component of resilient agricultural systems. Biochar’s long-term stability in soil makes it a valuable tool for farmers, ranchers, and landowners seeking to improve productivity while contributing to climate mitigation

The USDA Natural Resources Conservation Service (NRCS) provides financial and technical assistance to apply biochars on agricultural, forestry and other working lands. The Soil Carbon Amendment Conservation Practice Standard 336 (CPS 336) outlines the requirements of biochars, compost, and other carbon amendments to improve soil health and mitigate climate change. Financial assistance is designed around common application rates, including blended biochars and compost amendments. Many, but not all, states have list this practice available in their Field Office Technical Guide. Technical guides are the primary scientific references for NRCS that guide planning efforts.  

Federal, regional, and/or state Technical Service Providers can help you develop a conservation plan and find financial assistance. A conservation plan will identify natural resource concerns and prescribes a conservation practice standard to address each concern. If there is an existing resource concern that can be addressed through CPS 336, the applicant is then eligible for reimbursement for the compost and or biochars procured through the NRCS Environmental Quality Incentives Program (EQIP) In addition to EQIP, the Regional Conservation Partnership Program (RCPP) may also offer financial assistance for CPS 336, but in order to receive financial assistance through RCPP the practice must be available in an active project in your region. In addition, some states offer financial assistance for biochar application. Contact your local NRCS office or see the State Conservation Dashboard, linked below, to get an idea of which states offer conservation programs.

Decision support is essential for proper implementation of biochar applications. It’s Important to know how biochars can improve soil conditions and to define the purpose of the application. The following decision support tools will help you assess the right biochars and application process for your soils. 

USDA Web Soil Survey

The NRCS has incorporated a Dynamic Soil Properties Response to Biochar into the Web Soil Survey’s Soil Health Data Explorer. This tool uses the USDA soil survey data to determine the potential response to biochar applications rated from “unsuited” to “excellent”. This is a first-step screening tool and site-specific assessments of the potential response should be made before a final determination.

Pacific Northwest Biochar Atlas

The Pacific Northwest Biochar Atlas (the Atlas) is designed to provide guidance to farmers, gardeners, and other end-users on the potential benefits of biochars and to select biochar types and amendment rates. For users to get the most out of the Atlas, they should have their crop (species and nutrient requirements), soil (organic matter, nutrients, pH, CEC and texture) and biochar (total H%, total C%, available and total nutrients, CaCO3 equivalent, particle size class) data to enter into the tool. Users should also be able to prioritize their goals for applying biochars from a drop-down menu (e.g., sequester carbon, increase water retention, increase soil pH). The Atlas also includes many other resources, supports biochar producers, and houses several case studies. The current area of focus is the Pacific Northwest region; however, a national expansion of the tool is underway with an anticipated release in 2025.

Biochar Selection Tool

The Biochar Selection Tool allows you to input data about your soils in order to select the best type of biochar and amendment rate.

AFT’s growing Biochar Supplier Map provides a visual guide to biochar producers across the country who are supplying for agricultural needs. The purpose of the map is to facilitate farmers’ ability to find and select biochar producers within their region who can meet their needs, and to help biochar producers in locating areas with production needs. If you are a biochar producer currently producing biochar for agricultural use and you are not listed on the map, please notify us through the Biochar Supplier Form. If you find there is a discrepancy in any of the information provided here, please use the Map Correction Form.