Recently, Advanced Agrilytics hosted a webinar featuring Dr. Brandon Smith, Vice President of Agricultural Products at Stircor Services. Dr. Smith is an expert in biochar for agricultural uses. He also created the Soil Carbon Amendment Practice, which is now part of the National Resources Conservation Service’s (NRCS) Environmental Quality Incentives Program (EQIP), which provides financial assistance for adopting biochar as a conservation practice. Dr. Smith gave an overview of the benefits of using biochar in crop production and guidance for applying the product for maximum benefit. Here’s a recap:
What Is Biochar?
Biochar is a stable, carbon-rich material created by heating organic biomass, such as wood chips, sawdust, or crop residues, in a low-oxygen environment. This process is known as pyrolysis or gasification. Temperatures exceed 350°C, resulting in a porous, charged carbon structure that can remain in soil for hundreds of years without significant degradation.
The feedstock used to make biochar largely determines its physical properties. Regardless of source material, biochar is characterized by a network of macro-, meso-, and micropores. These pores not only change the soil’s overall porosity but also provide storage for water, nutrients, and beneficial microbes, improving soil structure and biological activity.
Benefits for Soil and Crops
Biochar’s value as a soil amendment is supported by extensive research. Dr. Smith referenced a meta-analysis of 26 global studies that found notable agronomic benefits:
- Root Development: Increases of roughly 52% in root length, 32% in root biomass, and 25% in nodule formation, particularly beneficial for legumes like soybeans.
- Soil Organic Carbon: Gains beyond the amount of carbon directly added, due to “negative priming,” where biochar slows the breakdown of existing soil organic matter.
- Water Management: A 15 to 20% increase in plant-available soil water and improved water use efficiency.
- Nutrient Cycling: Approximately 11% greater nitrogen uptake, coupled with a 12% reduction in nitrate leaching.
- Yield: Average increases of 10 to 13%, typically realized after one to three years as the soil system equilibrates.
Biochar also reduces nitrous oxide emissions and can modestly decrease soil bulk density, further contributing to favorable growing conditions.
The “Right Place” for Biochar
Biochar’s effectiveness depends on matching the amendment to the right soil conditions. Dr. Smith emphasized that the highest responses are typically seen in:
- Sandy or lighter-textured soils with low water- and nutrient-holding capacity.
- Low-fertility or low-organic matter soils, where biochar helps retain nutrients and build organic matter.
Poorly drained soils and highly productive fields often show limited agronomic benefit from biochar. In many cases, the issue is drainage rather than soil texture or fertility. NRCS soil maps classify such areas as “unsuited” (changing to “negligible” on October 1, 2025) when they are prone to ponding or have a high water table, meaning biochar can be applied, but a strong yield or soil health response is unlikely.
These ratings can change with field improvements. For example, areas mapped as having a high risk of ponding could become suitable for biochar once tile drainage is installed and functioning, especially if they are sandy or lighter-textured soils.
Because of this, field-level verification is essential. Growers should confirm actual drainage and soil type before excluding acres based on NRCS classifications. Some states now allow biochar on land initially marked unsuitable if adequate drainage is documented, enabling more precise targeting of acres for maximum agronomic and environmental benefit.
The “Right Time”
The optimal timing for biochar application depends on the crop:
Soybeans
For soybeans, the preferred application window is in the fall, ideally paired with a cereal rye cover crop. This allows the biochar to equilibrate in the soil over winter and into early spring, reducing the short-term nitrogen immobilization that can occur in the first year after application.
If biochar is applied in the spring, it is critical to apply it before planting soybeans (or any other legume), ideally by several weeks, not at planting. Early application allows the biochar time to interact with the soil environment, reducing the temporary nitrogen immobilization and nutrient competition that can occur in the first year. This timing helps ensure that seedlings have access to sufficient nutrients during emergence and early growth, while still aligning the application with a crop less dependent on soil-applied nitrogen.
Corn
Fall application is also recommended for corn, and it should be paired with a low carbon-to-nitrogen cover crop such as radish or oats, which will winterkill prior to planting. This reduces the risk of nitrogen tie-up early in the season. In-season nitrogen monitoring, such as using pre-sidedress nitrate tests, and split nitrogen applications in the first year after the biochar application, is strongly advised to ensure the crop has adequate nutrient availability during critical growth stages.
What is the Right Rate? It Depends…
For NRCS Practice 336, the minimum recommended application rate is four cubic yards per acre per year, though the long-term goal is to reach a cumulative 12 to 20 cubic yards per acre over time. The optimal rate depends on several factors, including soil type, crop rotation, existing organic matter, drainage conditions, and the specific characteristics of the biochar—such as bulk density, moisture content, and carbon composition.
While higher rates can be applied all at once, this is not recommended. NRCS originally designed the practice for phased application of smaller, annual increments over three to five years. This approach reduces risk in year one, allows growers to monitor crop response, and ensures consistent integration of biochar into the soil profile. It also helps mitigate the temporary nitrogen immobilization that can occur after initial application.
The Right Form: Raw Biochar vs. Agglomerated Biochar Granules
Biochar is available in several forms, including raw (unprocessed), pelletized, and agglomerated (densified) granules. Stircor recommends the agglomerated granule products for agricultural use. The table below compares the handling, storage, and application characteristics of raw biochar versus agglomerated (densified) biochar granules.
| Feature | Raw Biochar | Agglomerated (Densified) Granules |
| Dust | Very dusty; the product’s tiny particles easily go airborne during handling, storage and spreading | Dust-free |
| Wind Drift | Highly prone to drifting | Resistant to drift; heavier and more stable |
| Storage | Bulk piles must be covered or sheltered; they’re easily blown away if left exposed | Stores cleanly in supersacks, silos, or covered facilities without clumping if kept dry |
| Application Equipment | Works best with spreaders equipped with horizontal spinners; more difficult to spread evenly | Compatible with any standard fertilizer spreader; uniform throw pattern |
| Handling Safety | May require protective gear due to dust | Minimal PPE needs beyond standard precautions |
| Field Efficiency | Slower application, more product loss risk | Faster, more uniform application with less waste |
| Recommendation | Possible to use, but challenging | Preferred for most field situations |
Monitoring and Measuring Success
Dr. Smith stressed the importance of measuring soil organic carbon, not just soil organic matter, to capture biochar’s contribution accurately. Biochar is produced at high temperatures, making it resistant to breakdown in standard loss-on-ignition tests for organic matter. Establishing check strips in treated and untreated areas can help track changes over time and may earn additional EQIP ranking points under adaptive management practice codes. Dr. Smith recommends that growers consider using Adaptive Management for Soil Health (EQIP Practice 204) as part of their monitoring practices.
Financial and Program Support
Through the EQIP program, participating growers can receive cost-share payments for implementing the Soil Carbon Amendment practice. Stircor works directly with farmers and NRCS offices to provide compliant biochar at no cost to the grower, manage program documentation, and facilitate free product delivery. Once the practice is completed and certified, farmers may receive incentive payments, currently around $200 per acre, with higher rates for historically underserved producers.
A Long-Term Soil Investment
Biochar offers a unique combination of immediate and lasting benefits: improved soil structure, increased nutrient retention, enhanced microbial activity, and stable carbon sequestration for centuries. When matched to the right soils, applied at the right time and rate, and integrated into a broader conservation strategy, it becomes a powerful tool for advancing both agronomic performance and environmental stewardship.
Have questions or need more information? Contact us at info@advancedagrilytics.com.
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