It’s going to be a hot one this summer. Is your landscape resilient enough to take on another year of drought? You can future-proof your landscape by applying a biochar to enhance soil fertility. Improved soil health creates greater resilience in the entire landscape.
Last year, 2024, was the hottest on record, beating out 2023. We’re on an upward trend, and NOAA predictions are for “…record-breaking heatwaves, wildfires, and rising sea levels.”
You might ask: Can a biochar improve soil fertility on my land? The answer is yes, most of the time.
But the first question should be, what is biochar?
It’s not a single, uniform product; it’s a spectrum of biochars with different properties depending on feedstock, pyrolysis conditions, and post-processing treatments.
Raw biochar can initially adsorb nutrients before it desorbs them, meaning it can temporarily lock up essential soil nutrients rather than immediately benefiting plants. That’s why biochars need to be charged with nutrients and often microorganisms.
Let’s look at the sciences of soil and soil amendments to see how a biochar can improve your soil fertility.
Key Takeaways
- Biochar isn’t a single uniform product. The characteristics of the different raw materials that are pyrolyzed create characteristics beneficial for different end uses.
- Woody biomass produces the highest porosity biochars and is recommended as a soil amendment
- Charging biochar is necessary to avoid nutrient tie-up in raw biochar products
- The three main charging substrates are composts, manures, and humates
- The most consistent nutrient profile for soil amendments is achieved with pine biochar and humate charging
Unlock Soil Potential with Biochar – But Which One?
Biochars (plural) are diverse soil amendments whose characteristics are determined by the type of organic feedstock and the pyrolysis technique used. It’s important to know what raw material has been pyrolyzed. When you’re searching for a biochar product ask questions. Ideally, you want to find a single source organic material as the feedstock for the biochar.
Once you know the feedstock, you need to ask how that biochar was charged. Charging is inoculating biochar with nutrients and beneficial microbes before applying it to soil. Fresh, uncharged biochar acts like a sponge, absorbing nutrients from the surrounding soil, which temporarily reduces soil fertility.
Throughout millennia, biochar has been created by many indigenous cultures. Terra preta is found in South America, and charred remains of partially burned organic debris and organic waste are still being found buried across the globe.
We make it ourselves when we’re camping. When we cover the glowing coals with dirt or quench them with water. Cooking is often done on the same site, so digging down into any fire pit will unearth a biochar. This isn’t the highest quality biochar, but it does explain how it is made. Wood is often used for cooking fires. It is high in lignin, and the aromatic carbon structures contribute to a biochar’s carbon stability and long-term carbon sequestration.
Questions about how our biochar improves soil fertility are answered here.
Why Biochars (Plural) and What Are Their Applications?
Let’s look at the plurality of feedstocks that can become biochar. It is almost infinite because any organic material can be pyrolyzed, heated at high temperatures in the absence of oxygen, to produce a biochar and other products.
Which feedstocks are the best? It depends on your end-use. For agricultural purposes, when your goal is to increase soil porosity for water retention or root penetration, a wood-based biochar is recommended.
Woody biomass is divided into hardwoods and softwoods because they produce biochar with slightly different characteristics. All woods have a higher SSA (specific surface area) than any other feedstock material. They also have a higher PV (pore volume) because the cell structures in wood are quite large relative to other feedstocks.
Wood is divided into soft and hard woods, and softwoods tend to have a larger cell structure. Think of looking at the grain of a Southern Yellow Pine vs a White Oak wood plank. The pine has more space between the grain lines. After these two feedstocks are pyrolyzed, the difference in the pore sizes can only be seen at the microscopic level. But that difference makes all the difference to soil microbiology.
The SSA is greater in woody biomass because the relatively large cell structures decrease in size when the tar, oils, hydrogen, oxygen, and other organic compounds are removed through pyrolysis. Essentially, you end up with carbon skeletons of the biomass.
Read where we source our feedstock and our charging agent, Humates
The pyrolysis process volatilizes gases and water in the cell structure and the micro-molecular organic compounds, which leave voids in the biochar matrix. Imagine biochar as a sponge crossed with a coral reef. The sponge characteristic soaks up the nutrients and water; the reef is the biochar pores that act as microbial condos.
Crop residues such as corn, wheat straw, and rice straw all produce biochar with approximately the same physical and biochemical characteristics. They tend to have a higher pH and greater CEC (cation exchange capacity) but are highly variable. Biochar made from these materials should be tested for pH to determine if it will benefit your soil if you intend to use it as a soil amendment. The pH can range from alkaline to acidic, so know exactly what crop waste was used as feedstock.
Manures and biosolids (also known as sewage) are also candidates for pyrolysis into biochars. They may seem alike, but have slightly different end product biochars because, unlike woody biochar, they retain specific nutrients. The pore structures in manures and biosolids are less distinct, and the resulting biochars from these feedstocks have low SSA (specific surface area).
The pH of these feedstocks also ranges from highly acidic (fresh poultry manure) to neutral (dairy manure) to alkaline for treated municipal waste. And many variations in between. Pyrolysis temperature is a main factor in the pH of the finished biochars. Higher temperatures produce alkaline biochar, and lower temperatures retain acidic functional groups in the biochar.
From this brief explanation, it’s obvious there are major factors that determine the suitability of a particular biochar for an end use. Choosing the proper combination of biochar and charging raw material makes a difference for the sustainability of your landscape.
For an in-depth explanation of the different biochars and the factors that determine their differences, this is an excellent overview, that attempts to answer the question, what is biochar.
You have biochar, but is it a soil conditioner or amendment in its raw form?
No, it can’t be placed in the soil without charging.
So, what the heck is Charging?
Charging A Biochar: Why It Matters
Charging means pre-loading the biochar with nutrients and/or microbes to prevent initial nutrient binding in the soil. There are numerous methods to achieve a nutrient-filled carbon skeleton (biochar), and it all boils down to combining the biochar with any organic decaying materials.
Does this sound like we’re just adding the nutrients that we just removed through pyrolysis? That’s half right. The biochar itself has no nutrients but is a source for sequestering carbon. The resulting soil amendment blend does two things: it sequesters carbon, and the organic materials used to charge the biochar are immediately accessible to microbes and plants for optimum growth.
You can customize biochar by adding specific nutrients for different soil conditions and plant needs. For example, most soils are deficient in boron, and most plants need nitrogen; you can “charge” using compost for nitrogen and a foliar spray of micronutrients for boron to create a nutrient-enriched biochar.
Multiple organic materials and techniques are used to charge a biochar.
A Compost as a Cost-Effective Organic Charge for A Biochar
Your kitchen scraps, grass clippings, and any other organic material that goes into your compost pile are good for charging biochars. One convenient method is to sprinkle biochar on the top of your compost pile every time you add new organic material to it.
Home compost piles sometimes have an odor and attract flies. Biochar on top of the compost pile does two things:
- Reduce odor
- Reduce any type of fly activity
Why? A biochar is similar to an activated charcoal filter. It is collecting the greenhouse gases that decaying organic materials always emit. Those gases are actually nutrients in gas form. When compost isn’t prepared properly, you can actually contribute to greenhouse gas emissions and air pollution. We measure carbon dioxide emissions, but they are only one of the many greenhouse gases.
So, what is happening is that the biochar is filling its pore structure with nutrients that would have escaped into the atmosphere. It is making your compost pile more efficient. When you turn your compost, you are incorporating carbon into the pile, so when you use it as a soil amendment, you sequester carbon.
No compost pile? Follow this link, your beautiful landscape begins with our biochar
Manures as Effective Charging Media for a Biochar
All types of manure and biosolids emit odors; just go past your neighborhood dairy on a breezy afternoon. That “farm smell” is valuable nutrients being emitted into the air as greenhouse gases. The farmer is losing valuable crop amendments if you can smell the farm. Methane is about 30 times more potent than CO2, and it largely comes from agriculture and fossil fuels, think confined animals, diesel tractors and other farm equipment.
Manure is a valuable resource for agricultural productivity, providing essential nutrients to crops and improving soil health. Traditionally, farms have spread manure directly onto their fields to enhance soil fertility and promote plant growth. However, while this method can be effective, it often leads to nutrient loss due to runoff and volatilization, which can diminish the benefits of this organic fertilizer. This is where biochar comes into play. When manure is mixed with biochar, a stable form of carbon produced through pyrolysis, it acts much like compost, creating a nutrient-rich amendment that retains more of the essential elements present in the manure.
The incorporation of biochar into manure not only helps to stabilize nutrients but also enhances the overall soil structure and water retention capabilities. Because biochar has a porous structure, it can absorb nutrients and water, allowing for gradual release into the soil over time. This means crops have better access to the nutrients they need without the risk of immediate leaching. By keeping more nutrients on the farm and reducing the potential for environmental pollution, the combination of manure and biochar promotes a more sustainable agricultural practice. This method can lead to healthier soil ecosystems that support biodiversity, ultimately contributing to more productive and resilient farming systems.
The nutrients in manure are as variable as the diet of the livestock. High-protein diets lead to increased nitrogen content in the manure. Fiber-heavy diets, like those found in cattle, produce a manure with more organic matter, and that improves soil structure.
Other variables factor into the nutrient content of a manure. The animal species has a huge impact. Poultry manure is high in nitrogen, swine manure is high in phosphorus, and cattle manure has high organic matter and nitrogen. Knowing this and using a manure as a charging agent for your biochar helps you optimize manure applications for better nutrient management.
Biochars that use manures, as with composts, have the disadvantage of an inconsistent nutrient profile. All manures, when used with care, are great soil conditioners and are definitely a renewable resource!
Want a consistent source of nutrients for your lawn, roses, or garden? Follow this link!
The Value of Humates to Charge a Biochar for Soil Fertility
If you want a consistent charging agent, humates, sourced from a specific geological deposit, will give you that characteristic.
Humates are derived from ancient, decomposed organic matter that has undergone millions of years of natural humification, leading to a stable composition. Relatively stable, because the carbon and nutrients in humates are immediately accessible to microbes and plants as fuel.
Fulvic and humic acids found in humates improve nutrient efficiency and soil health. The functions of humic acid are to enhance nutrient exchange and stimulate microbial activity. The molecular size of a fulvic acid molecule is so small that it is absorbed through the plant cell membrane, bringing with it nutrients such as iron, calcium, and magnesium. Multiply this by the millions of fulvic acid molecules, and you have a powerhouse for plant and soil health.
Composts, Manures, or Humates; What’s Best for Charging Biochars?
Combining any of these organic materials with biochar will improve your soil and plant health. But there are differences.
Composts are variable in nutrients and microbial life based on the inputs. It’s seldom that the ingredients of two batches of compost are the same. But in combination with a biochar compost does enhance water retention, usually balances pH, provides organic matter for immediate nutrient accessibility, and supports microbial diversity.
Manures deliver immediate nutrients, especially nitrogen, phosphorus, and potassium. The quality of the manure is based on the quality of the animal’s diet. Manures tend to support greater microbial activity because they already have a diverse microbial population.
A biochar and manure blend can improve soil texture, reduce compaction, and enhance aeration. The caveat with manures is that animals have to rid themselves of salts, and heavy and frequent applications of manure can introduce salts, leading to salinity issues.
At American BioChar Company, our research has shown us that humates are superior as a charging agent to any other organic material. This is primarily because, as a farmer, rancher, or turf management professional, you need to have consistent results.
We understand your need for consistent results and believe that the science underground must be correct for beauty and productivity above ground.
Pairing biochar and humates creates a powerful synergy that enhances soil health, nutrient retention, and plant resilience. Together, they create a natural, slow-release nutrient system. The biochar supplies a stable habitat for beneficial microbes, and the humates stimulate microbial growth and activity, increasing soil biodiversity.
A Charged Biochar for Soil Fertility and Resilience in Your Landscape
It looks like climate change is going to give us a hot summer in 2025. When you incorporate biochar and organic matter into your fertilizer routine, you create greater soil health and plant resilience.
Using a blend of organic matter and biochar for turf management is an especially productive strategy for golf course management as well as home lawns. The biochar improves soil structure and helps lawns retain moisture. Our product VITAL Blend incorporates humates and softwood biochar to create optimum soil porosity and turf health.
In no-till and specialty agriculture, a biochar blend sequesters carbon while adding nutrients. Soil microbiological activity is activated with humic acids from humates. The native microbiology is there; it just needs some fuel to begin cycling nutrients for optimum plant health.
The fulvic acid and micronutrients in humates are readily incorporated into the cell tissue through endocytosis & diffusion, and membrane transport. These mechanisms regulate ion transport and nutrient uptake for improved stress tolerance and root growth.
Healthy plants and active soil microbiology create resilience in landscapes. If you’re not sure how a biochar blend will work, try a test on a portion of your lawn or garden. Become a citizen scientist and include your kids and grandkids in the experiment. Taking pictures and keeping track of plant growth is a sure-fire way to see if it works. It also gets the whole family involved.
Our products at American BioChar Company are OMRI-listed (which means they don’t have toxic chemicals) and IBI (International Biochar Initiative) certified. They are safe for wildlife, kids, pets, and you in your landscape.
