Description

Biochar is a carbon rich material obtained through partial combustion of biomass, typically cropped residues, manure, or forest slag. Biochar can be applied as a soil amendment to raise soil pH, reduce nitrogen leaching, and increase water holding capacity. It can also be incorporated into soils to increase carbon sequestration. See NRCS Soil Carbon Amendment practices (Code 336 or 808).

Benefits

Biochar helps to buffer soil pH with associated nutrient availability benefits. Biochar contains some mineral nutrients in addition to carbon. It has high cation exchange capacity. It can improve soil structure. It can absorb some contaminants of soil. It increases soil moisture retention, potentially minimizing leaching losses and possibly increasing crop yields.

Soil Carbon Impacts

As a soil adjuvant biochar directly incorporates carbon in a relatively stable form into soil.

Greenhouse Gas (GHG) Impacts

Typically, the fuel source for biochar would otherwise decompose, releasing CO2 into the atmosphere, so biochar provides a method for carbon capture.

Considerations for Success

• Biochar applications may not improve crop performance or yield as anticipated.
• Costs associated with the higher application rates may be substantial and well above incentive payments.
• Recommend mixing biochar to a depth of 6 to 12 inches following field application.
• Not all biochar is the same and therefore needs to be tested to understand the characteristics of the biochar.
• It is possible that the biochar results in net nutrient retention and possible nutrient stress. Mixing or conditioning biochar with compost or other nutrients can minimize the risk of nutrient stress, particularly phosphorus stress.

Options

See NRCS Soil Carbon Amendment (Code 336), and NRCS Soil Carbon Amendment (Code 808).

IAMP Preferences/Considerations

The IAMP project incentivizes practices that result in a net reduction in GHG and increase in soil carbon. Biochar, whether procured or produced on-farm, provides a potential GHG savings over BAU. GHG savings from biochar can be estimated relative to CO₂ emissions that would be emitted by the unprocessed biochar feedstock. One IAMP partner, the Coeur d’Alene Tribe, will be manufacturing biochar on its Tribal lands to document the cost of production. The Coeur d’Alene Tribe will also apply biochar to a demonstration site to test its effectiveness for improving crop production. Other IAMP participants may elect to implement biochar depending on availability and costs. Depending on those costs, IAMP incentives may only offset rather than fully cover the costs of biochar application. IAMP is investigating biochar sources suitable for the project and producers should consult with an IAMP representative for the status of those sources. Other benefits of biochar can be considered as additional to CO₂ mitigation accruing to the producer.

Specific Details

• Use biochar that is produced by heating biomass to a temperature in excess of 350°C under conditions of controlled and limited oxidant concentrations to prevent combustion (pyrolysis or gasification).
• Biochar analysis must report:
• Country of origin of biochar and feedstock, and feedstock composition.
• Production method (e.g. verification of temperature and limited oxygen conditions).
• Organic carbon, ash, nitrogen, pH, EC, liming equivalent, phosphorus, potassium, and pH of the final material.
• Use laboratories successfully meeting the requirements and performance standards of the International Biochar Initiative (IBI) Seal or use an alternative NRCS- or State-approved certification program that considers laboratory performance and proficiency to assure accuracy of laboratory analyses.
• Do not use biochar produced from:
• Crop residues that could otherwise be left on the field to provide soil protection and improve soil organism habitat, or
• Woody residue needed to sustain forest health and wildlife habitat referenced in NRCS CPS Forest Stand Improvement (Code 666).

Criteria/Verification

Inspection by implementing partner. Both Tier 1 and Tier 2 growers will provide a record of the biochar application rate and timing, source of the biochar, and specific characteristics of the biochar provided by the supplier.

Incentive Payments

$60/acre in the year of application.

Stacking or Companion Practices

Biochar amendments are compatible with other incentivized IAMP practices. Cover crops, Conservation crop rotation (>2 crops), Intercropping, No tillage from conventional, Reduced tillage from conventional, Nutrient Management, Prescribed grazing, other Soil Carbon amendment.

Sources

• NRCS Soil Carbon Amendment (Code 336)
• NRCS Soil Carbon Amendment (Code 808)