There’s no doubt biochar can benefit many different types of soil. Due to its high adsorption and nutrient holding capacity, biochar can prevent both water and nutrients from leaching while still allowing them to be readily available to plants. These properties, which can significantly improve your soil’s fertility, also make biochar useful in reducing water erosion and fertilizer runoff.
Still, you may be wondering how exactly you should use and store biochar for your specific application. The answer depends on a few things, like how fertile your soil is before applying biochar, or whether you intend to use biochar to grow crops.
Using biochar in near-term applications
Incorporating biochar into soil and compost can greatly enhance their fertility and overall health. To effectively use biochar, start by ensuring that it is properly cured and free of contaminants. For soil incorporation, determine the appropriate application rate based on soil type, desired outcome, and specific crop requirements. It is recommended to mix biochar evenly into the soil to a depth of at least 6-12 inches. Consider using a ratio of 5-10% biochar by volume to begin with, gradually increasing the amount if desired results are not achieved. Additionally, it is beneficial to pre-soak biochar before application to improve water retention.
Charging up your soil with biochar
In the rare case that your soil is already very fertile, biochar can be directly added to the soil. Biochar, however, brings the most benefits to soil when it is “charged” or inoculated with nutrients and soil microorganisms to help prime your soil for improved fertility.
Though many different methods for charging biochar exist, most procedures follow several basic principles, which include:
- Containing enough moisture for nutrients to dissolve and adsorb to the pores of the biochar
- Introducing a wide variety of nutrients
- Inoculating soil-borne microbes through compost or other methods
- Letting the charge progress at least 14 days, to allow beneficial soil biology to inoculate
Charging should be tailored to your situation. For most near-term applications, it is best to blend the biochar with a high-quality compost containing the biology that would most benefit your plants.
If you are not sure about the quality of your compost, you can try one of CharGrow’s proprietary products, BioChar Source™ or BioGranules™. Both are charged, or inoculated, biochar that have already been loaded with beneficial microbiology and microbial food and have proven growing results. Field trials on growing media and soils in the United States have demonstrated that BioGranules enhances biological activity and plant performance when it is added at 2 to 3 percent by volume in growing mixes or 15 to 20 pounds per acre in row crops.
Incorporating biochar and compost into your soil
Compost can be mixed with biochar before being added to the soil or it can be worked into the field when it is being applied. In the latter case, the biochar would be laid on top of the soil first, then the compost, before they are mixed into the soil through tilling or other methods. The ratio between compost and biochar can be as high as 1:1 and the biochar is left to inoculate for at least a couple of weeks.
In some cases, the biochar and compost are partially mixed while they are being transported to a field. Here, biochar and compost is loaded into a truck in alternating layers before it travels to the field.
Biochar and compost blend
When incorporating biochar into compost, blend it with other organic materials such as kitchen scraps, yard waste, or manure. Aim for a balanced carbon-to-nitrogen ratio and ensure proper aeration and moisture levels in the compost pile. Regularly turn the compost to facilitate decomposition and evenly distribute the biochar throughout the mixture. By following these guidelines, you can effectively incorporate biochar into soil and compost, maximizing its benefits for plant growth and soil health.
Alternatives to compost inoculation
Biochar can be mixed into a field intended for cover crops. Cover crops are plants that are grown to improve soil health and other aspects of soil for the crop that will follow (for example alfalfa that is grown prior to planting sweet corn). After mixing in biochar, the native microorganisms already present in the field move into the biochar over several months. This method of charging has been especially successful when the cover crops are nitrogen-fixing legumes such as clover.
Biochar can also be charged with other materials such as liquid fertilizer
Incorporating biochar into potting mixes
Incorporating biochar into potting mixes and garden beds can significantly enhance plant growth, soil structure, and nutrient availability. Here are some recommendations to effectively integrate biochar into your gardening practices:
- Consider the Right Ratio: When incorporating biochar into potting mixes or garden beds, it is crucial to determine the appropriate ratio. Start with a ratio of 10-20% biochar by volume and adjust as needed based on plant requirements, soil type, and desired outcomes. Gradually increasing the biochar content allows you to observe its impact and make necessary adjustments.
- Uniform Distribution: Ensure that the biochar is uniformly distributed throughout the potting mix or garden bed. Thoroughly mix the biochar with the other components, such as compost, soil, or peat moss. This uniform distribution helps maximize its benefits and prevents localized nutrient imbalances.
- Pre-soak Biochar: Prior to incorporation, pre-soaking the biochar in water can improve its water-holding capacity and prevent it from drawing moisture away from plant roots initially. This step also aids in the biochar’s integration into the potting mix or soil.
- Complementary Organic Matter: Biochar works synergistically with organic matter. Incorporating biochar alongside compost, aged manure, or other organic materials enhances nutrient retention and improves soil microbial activity. Combining biochar with organic matter creates a nutrient-rich environment, promoting healthy plant growth.
- Moisture Management: Biochar has excellent water retention properties, which can be advantageous, especially in dry or sandy soils. However, it is important to monitor moisture levels carefully. Ensure proper irrigation practices, avoiding overwatering or waterlogging. Adjust watering schedules and amounts based on the specific needs of your plants.
- Long-Term Benefits: Biochar’s effects on soil health and fertility are long-lasting. Incorporating biochar into potting mixes and garden beds provides a lasting impact, improving soil structure and nutrient availability over time. As a result, your plants will experience improved growth, resilience, and overall vitality.
The best place to put biochar
The best location for biochar depends on your application.
If biochar is used as a soil amendment, you should work the biochar into the plant’s root zone – the part of the soil surrounding a plant’s roots – incorporating the biochar into 4 to 6 inches of soil depth if possible. This way, you will make full use of biochar’s remarkable capability to hold water, retain nutrients, and host beneficial soil biology. Working the biochar into the soil also minimizes the chance that the biochar will be disturbed, dried out, or blown away.
If biochar is used to purify storm water, filter contaminants, or reduce erosion, you do not necessarily need to work biochar into the soil. In these situations, biochar is used in locations that are optimal for the specific needs of the project and often placed within containers specialized for each use case, such as landscape socks and filtration systems. For example, you can place the biochar where water is running off land, roofs, roads, or other contaminated sites – including those that are aboveground.
Best management practices when applying and storing biochar
Ensuring the safe handling and storage of biochar is essential to minimize potential risks and maximize its benefits. Here are some guidelines to follow:
- Personal Protective Equipment (PPE): When handling biochar, it is important to wear proper PPE. This includes gloves, long-sleeved shirts, long pants, and safety glasses or goggles. These protective measures will shield you from potential irritants and dust particles.
- Dust Control: Biochar can generate dust, which may be harmful when inhaled. To minimize dust, dampen the biochar before handling or use wetting agents if necessary. Consider working in well-ventilated areas or use dust extraction systems. This will help reduce the risk of respiratory issues and ensure a safer environment.
- Storage: Store biochar in a dry and well-ventilated area to prevent moisture absorption and the growth of mold or bacteria. Use sealed containers or bags to protect it from environmental contaminants. Avoid storing biochar near flammable materials or heat sources to prevent the risk of fire.
- Handling Precautions: Avoid excessive agitation or unnecessary movement of biochar to minimize dust generation. When transporting or moving large quantities of biochar, use appropriate lifting techniques and equipment to prevent injuries.
- Fire Safety: Biochar is highly flammable, especially in fine particulate form. Keep fire extinguishers readily available and ensure that your storage area complies with fire safety regulations. Regularly inspect the storage area for potential fire hazards and maintain a clear evacuation plan.
- Education and Training: Provide proper training and education to individuals handling biochar. Familiarize them with safety procedures, potential risks, and emergency protocols. Promote awareness of biochar handling and storage guidelines to prevent accidents and promote a culture of safety.
Most biochar products have fine, dust-like particles that can be swept away by wind or water if proper precautions are not taken.
The best way to prevent your biochar from being lost to wind is to moisten it. This helps weigh down the biochar dust and is the reason why CharGrow’s BioChar Prime™ product is pre-moistened prior to shipping (though customer moisture specs can be accommodated).
Whether or not you moisten the biochar yourself, you should always consider its moisture content when determining your application rate, as you may over- or underestimate the amount of biochar you require for your situation. You should always apply biochar in the right weather conditions and when winds are mild.
Water can sweep biochar away, especially at sites with steep slopes or high rainfall. To prevent your biochar from being lost to water, you should properly incorporate the biochar into the soil or apply biochar with wetter materials such as compost or mulch, depending on the types of plants you are growing.
By adhering to these guidelines, you can safely handle and store biochar, reducing risks and ensuring a safe working environment. Remember, prioritizing safety is crucial to fully harness the potential of biochar while protecting both individuals and the environment.