Biochar is an exciting component being added into growing practices, ranging from applications in home gardens to large-scale agriculture. CharGrow can help address many of the questions that you have and offer some suggestions on using biochar in your home garden.
Benefits of gardening with biochar soil amendments and inoculants
When incorporated into a home garden, biochar can:
- Reduced soil compaction,
- Reduced irrigation input,
- Reduce fertilizer input, and
- Reduced fungicide input
When added together, these benefits significantly improve plant performance.
Restoring soil biodiversity in home gardens
Most soils contain some elements of a healthy soil food web. However, in many cases, the diversity and population of soil biology are inadequate for plants to thrive. So what is the best way to build a thriving soil food web? Restore the population and biodiversity that was once present.
What is biochar?
Biochar is a carbon-rich solid that can significantly improve your soil’s health and productivity, especially if it is not already very fertile. For example, biochar benefits include decreasing soil acidity, retaining water and nutrients, removing unwanted contaminants, and providing a home for beneficial soil biology to thrive.
How is biochar made?
Biochar is derived from biomass (organic matter from plants ) that is heated in a limited oxygen environment. Essentially, the cellular structure of plant matter remains in pure carbon form, creating a honeycomb scaffolding with a network of walls, channels, pores, and micropores.
How to use biochar in home gardens
Charging or inoculating biochar
You’ve probably already read about “charging” or “inoculating” biochar. As described above, biochar is a very porous material that can hold or retain things like nutrients, water and biology. Used in its pure form, biochar will suck up those elements from the soil that its put into.
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 improve your soil’s fertility.
There are two ways to get started with biochar in your garden:
- Inoculate pure biochar yourself. Read more information about charging or inoculating biochar.
- Purchase a biochar amendment or inoculant that is already charged and ready to be applied to the soil.
CharGrow’s biochar products allow home growers to put the proper biology back into soils so plants can achieve optimal health and performance.
CharGrow BioGranules™ is a granular carbon matrix containing concentrated beneficial soil microorganisms (bacteria, fungi, protozoa, and nematodes), enriched substrates, and microbial foods. Research has shown that this formulation allows the microbes to survive harsh soil environments, increase nutrient cycling, and improve plant health.
There are many considerations when applying biochar to your garden, potting soils and beds. The existing fertility of your soil comes into play, along with the structure of your soil. For example, are you starting with clay or sand that needs a lot of help?
A recommended average, by volume, is to incorporate biochar at 10% of your soil. Applying biochar in a range of 5-20% by volume in garden soil is dependent upon some of the factors mentioned previously.
Also recommended is to charge or inoculate biochar prior to putting into soil. A common blend is 50% biochar and 50% high quality compost. In this 1:1 ratio, a sufficient supply of nutrients and beneficial soil biology should be supplied by the compost to satisfy the adsorption and absorption capacity of biochar. Note that the volume of the blended amendment has doubled, so it will be applied at 20% by volume to the soil, netting 10% biochar.
Following are example application rates for pure biochar and a 50/50 biochar-compost blended soil amendment to net 10% biochar in the soil.
When dealing with potting soils, the total volume of media will be amended.
Amending 1 cubic foot of soil
Add 2.85 quarts of pure biochar to 1 cubic foot of soil.
Add 6.43 quarts of 50% biochar-compost blend to 1 cubic foot of soil.
Amending 1 cubic yard of soil
Add 3 cubic feet of biochar to 1 cubic yard of soil
Add 6.75 cubic feet of 50% biochar-compost blend to 1 cubic yard of soil
1 dry cubic foot (ft3 , cu ft) = 6.43 dry gallons US (gal) = 25.72 dry quarts (qt)
1 cubic yard (yd3, cu yd) = 27 cubic feet (ft3, cu ft)
An easy calculation that gets pretty close is to simply multiply the amount of soil or growing media you have by 10% (0.1). While this calculation will give you slightly less than 10% of the total volume when biochar and soil are combined, it’s far easier than the precise calculations below.
Equations for 1 cubic foot
20% (half biochar, half compost)
Equations for 1 cubic yard
x=3 cu ft
20% (half biochar, half compost)
Garden beds and plots
When working with garden beds and plots, the top 4-6 inches of soil (the root zone or rhizosphere) will be amended.
Let’s say you have a 20 foot by 50 foot garden, or 100 square feet.
Amending 100 square feet of garden
Add 4 cubic feet of pure biochar to every 100 square feet of garden. Apply a 1/2 inch layer of biochar and till into top 4-6 inches of soil
Add 8 cubic feet of 50% biochar-compost blend to every 100 square feet of garden. Apply a one inch layer of biochar blend and till into the top 4-6 inches of soil