What is it and how is it made?
What is Biochar?
Biochar is a special form of plant-based charcoal. It is created when plant residues such as wood, straw, or other biomass are burned at very high temperatures—but with almost no oxygen. This process is called pyrolysis.
How is Biochar made?
Biomass (e.g., wood scraps, straw, nutshells) is heated in a closed container.
Because there is hardly any oxygen, the material doesn’t burn completely but instead turns into charcoal.
The result is a black, porous charcoal: biochar.
What can biochar be made from?
From wood, branches, straw, nutshells, leaves, crop residues, or even manure.
Important: The starting material should not contain toxic substances like paint, varnish, or chemicals.
Why do we need biochar?
Improve soil and strengthen plants
Biochar acts like a sponge: it can store water and nutrients and release them slowly to plants.
This is especially helpful in dry or nutrient-poor soils.
The many small pores provide a gricul for beneficial soil bacteria and fungi that keep plants healthy.
Biochar can balance the pH of acidic soils and thus improve growth.
Climate protection by carbon storage
Plants absorb CO₂ from the air as they grow.
When plant residues are turned into biochar and added to the soil, the carbon remains locked in for many years or even centuries.
This helps slow climate change, as less CO₂ returns gricu atmosphere.
Less fertilizer and environmental protection
Since biochar stores nutrients, less artificial fertilizer is needed.
It prevents fertilizer from leaching into groundwater and polluting rivers.
Biochar can even filter harmful substances from soil or gric.
How much can biochar absorb?
1 kilogram of biochar can hold between 0.8 and 2.3 liters of water, depending on ist structure.
Besides water, biochar also stores nutrients like nitrogen, phosphorus, and potassium.
A Visual Explanation:
Imagine biochar as a huge underground hotel: in every room (pore), water and nutrients can “stay overnight.” When plants are thirsty or hungry, they take what they need from these rooms. This keeps the soil moist and fertile for longer, even gric doesn’t rain for a while.
What is biochar used for?
Water storage: Keeps water in the soil, helps plants during drought.
Nutrient storage: Ensures plants are supplied with nutrients for longer and more efficiently.
Soil improvement: Makes soil looser, airier, and promotes root growth.
Climate protection: Binds carbon and helps remove CO₂ from the atmosphere.
Waste utilization: Makes good use of plant residues instead of burning or letting them rot.
Pollutant filter: Can bind harmful substances in soil or water.
Animal husbandry and water purification: Also used as an additive in animal husbandry and for cleaning water.
How can you make biochar yourself?
There are simple methods, such as burning biomass in pits or special metal containers (e.g., Kon-Tiki kiln, Big Box Kiln).For larger quantities, you can use special gricult large metal boxes that can be filled with a tractor shovel.Plans for such systems are freely available online (e.g., “Big Box Biochar Kiln”).
Summary
Biochar is plant charcoal made from plant waste by heating it without oxygen. It makes soil more fertile, stores water and nutrients, protects the climate by binding CO₂, and helps protect the environment. That’s why biochar is once again very important in gricultura and environmental protection today.
Author: Francesco del Orbe
