How Much Biochar Should You Use?
Applying biochar to your soil can be a fairly easy task. It is important to know how much biochar to use before you get started. You will need to consider the current conditions of the soil and whether you should mix your biochar with compost or worm castings before adding it to your soil. There are many benefits to biochar and you will get the most out of it with a quick survey of your current soil conditions.
Why Apply Biochar To Your Soil?
The key benefits of biochar can start with the general idea of soil health. In landscaping that may be most important phrase you want hear. It will, more than anything, make the soil you use for your planting healthier. That creates a stronger plant that looks better and lives longer. To better explain how biochar improves soil here is a summary of the benefits that occur.
Drought Resistance
- Keeps the moisture in the soil longer with all of the pores built into the biochar structure.
- The strength of the carbon keeps intact and gives your plants a fighting chance when the rain isn’t coming as often as you need it.
- Soil moisture retention is increased up to 20 percent (Plant Available Water).
- Biochar water holding capacity can range from 25% to 56% by volume.
- Biochar mixed with peat has a similar water holding capacity as peat alone.
- Peat with perlite is equivalent
- A 15% v/v biochar mixture with peat has similar water holding capacity as pure peat and is considered a suitable application for a rooting medium in horticulture.
- By weight, biochar is lighter:
- 3 x than sand
- 2.8 x than soil
- 2.1 x than water
Aeration
- Compact soils will benefit from biochar’s porous structure.
- It will increase water flow through the soil and allow for better root growth.
- On a dry ash-free basis, high quality biochar is over 85 volume percent empty space.
Long Lasting Impact To Soil
- Cation Exchange Capacity gets better with age.
- Nutrients are not leached away and keep your plants healthy.
- Biochar’s carbon structure creates a perfect shelter for beneficial microbes to live and grow without being washed out or starved for nutrients.
- Increased fertilizer efficiency by 10 to 60%
The Bottom Line – Stability and Affinity
- Stability – The carbon ring formations are stable. The carbon will not decompose.
- Affinity – The interior of the pores has a slight negative charge. The biochar will hold onto water and nutrients which will then be provided to the plants.