How to Make Your Compost Better (Yes, Biochar Gets a Shout)

Episode Overview

• The host, Jesse, answers a patron's question about biochar, specifically if the charcoal from a wood stove can be used and how to apply it.
• He emphasizes the value of adding diversity to compost to improve its quality, suggesting several methods.
• Jesse discusses the impact of adding biochar, rock minerals, worms, indigenous microorganisms (IMO), and allowing compost to mature.
• He also addresses a viewer's question about whether biochar can deactivate herbicides in soil, concluding that while it may retain them longer, it doesn't necessarily reduce their efficacy to the point of being a reliable remediation strategy.

Key Concepts

• Biochar vs. Wood Stove Charcoal: Biochar is a highly stable form of carbon produced by burning carbonaceous material at high temperatures in a low-oxygen environment. This creates a porous material that retains water and nutrients and provides a habitat for microbes. Wood stove charcoal, formed in a more oxygen-rich environment at lower temperatures, is less stable and won't last as long in the soil, but can still offer some benefits, especially when inoculated with compost.
• Inoculating Biochar: Biochar should not be added directly to soil without first being "charged" or inoculated. Applying raw biochar can lead to nutrient tie-up, as it will absorb nutrients and microbes from the surrounding soil. It should be mixed with compost or potting mix before application.
• Applying Biochar in No-Till Systems: Since tillage disrupts soil structure, biochar can be applied without tilling by adding it to potting mixes, seeding it directly into the ground with a seeder, broadcasting it and letting a seeder push it in, or using a broadfork to create cracks and sprinkling it in.
• Enhancing Compost with Rock Minerals: Adding rock minerals (like rock dust or kelp) to compost is beneficial because plants cannot directly access these nutrients. Microbes in the compost use enzymes to break down these minerals, making them plant-available. This process takes time, making the compost pile an ideal environment for this to occur before application.
• The Value of Worms (Vermicomposting): Introducing worms to finished compost can significantly increase its nutrient content and microbial diversity. Worms digest pathogenic organisms, buffer pH, and improve the water-holding capacity of the material.
• Indigenous Microorganisms (IMO): Sourcing diverse microbes from local environments (like a forest) using methods from Korean Natural Farming (KNF) and adding them to compost can create a more robust and effective amendment.
• The Importance of Compost Maturation: Allowing compost to rest for several months after the hot (thermophilic) phase is crucial. Immature compost can harbor diseases and weed seeds. Maturation allows the compost to stabilize, resulting in a crumbly, rich material with smaller particles that are easier for microbes to process.
• Diversity in Compost Ingredients: A high-quality compost requires a diverse mix of inputs. Different manures (e.g., chicken vs. cow) harbor different microbes and nutrient profiles. A mix of carbon sources (wood chips, straw) and nitrogen sources ensures a balanced and biologically rich final product.

Quotes

• At 2:00 - "biochar is kind of a specific thing where a special form of charcoal is made in high temperature but low oxygen environments which opens up the pore space in the charcoal itself... and it enables it to become a highly stable form of carbon with lots of microbial and nutrient housing." - This explains the physical properties and benefits of true biochar.
• At 9:00 - "The reason I like running rock minerals and things like kelp through compost before applying it to the soil is that plants can't really eat rock minerals. Plants need a microbe to use its little keys called enzymes to unlock that nutrient." - This highlights the importance of microbial action in making nutrients available to plants.
• At 14:26 - "The thing is that immature composts can have a wide diversity of microbes but they can also contain and support disease-causing organisms. Mature composts loosely defined as composts that have fulfilled their thermophilic again the hot stage and been allowed to rest." - This emphasizes the need for a curing phase to ensure compost safety and quality.

Takeaways

• To improve your compost's nutrient profile and microbial diversity, try incorporating a wider variety of materials, such as different types of manures and carbon sources.
• Before adding biochar to your garden, ensure it is properly inoculated by mixing it with compost or potting soil to prevent it from absorbing nutrients away from your plants.
• If your soil is deficient in certain minerals, consider adding rock dust or kelp to your compost pile rather than directly to the soil, allowing microbes to break them down into plant-available forms over time.