Why is biochar useful?

When a plant mature it uses water and nutrients from the soil. Fine roots evolve into the tiny spaces between the soil particles and nutrients flow across from the soil water into the cells in the roots. It is a world we cannot see that is reliant on microbial activity in those small soil spaces.

Biochar is carbon with a microscopic honeycomb arrangement with the actual size of the pore spaces dependent on the type of biomass used and the method of pyrolysis. This honeycomb arrangement is ideal for both holding water, providing micro-habitat for microbial activity and enhancing nutrient exchange between the soil and plant roots.

The carbon in char is fixed and resists further degradation or decomposition even when it has been in the soil for hundreds of years.

These equity make biochar an excellent soil amendment that can help improve poor or degraded soils.

What we call poor soil is soil that has low height of plant nutrients, or has nutrients locked away in clouds that roots cannot penetrate, has low oxygen levels and is either dry or waterlogged.

All these conditions are hard for plants to prosper and this, in turn, limits soil biological activity as there are fewer organic inputs to sustain soil animals and micro-organisms.

Healthy soil that supports plant production is

Aerated

Has a stable physical structure

Biologically active

High in carbon and

Retains moisture

These properties benefit efficient nutrient exchange and strong plant growth.

Applying soil amendments can help improve soil health and biochar fertilizer is one of the better amendments to apply because of it

Adds carbon

Helps retain water

Improve soil water quality

Reduces nutrient losses leaching)

Helps lower acidity

Together these benefits can also reduce the need for fertilizers and irrigation. The exceptional thing is that these benefits can apply to the soil in your garden as well as an arable field.

The biochar opportunity

In the next 30 years, global demand for food and fiber to support a growing and increasingly affluent human population can only be met from a doubling of current agricultural production. Whilst we have doubled production before this has been through clearing land for production, the use of artificial fertilizers and improved crop varieties.

These options are now far more difficult as most of the useable arable land is already in use, fertilizer use is becoming less effective [and more costly], and genomics has already made its biggest gains.

Making matters bad is that a significant amount of agricultural land is degrading after many generations of crop production. In many areas, soil aspect is declining with loss of carbon and nutrients and, at the severe, is being lost to wind or water erosion.

The biochar attribution is to attain agricultural production gains through a focus on soil quality by adding carbon to the soil.

Biochar is ideal for this purpose. It is an inactive form of carbon that would immediately increase the carbon content of the soil. The honeycomb arrangement of biochar increases the surface area of soil providing vital micro-sites for microbial growth and nutrient exchange. The honeycomb also helps in retaining moisture that, in turn, promotes biological activity.

A valuable bonus is that adding carbon to the soil is a form of carbon sequestration, an activity that will help offset greenhouse gas emissions.

Biochar is one of those rare opportunities to recover biomass that would otherwise go to waste and make a material that can help solve problems in agriculture and climate change mitigation.