Rock powder and biochar are two of the most powerful tools for reversing climate change, especially when used together.

This article is partly based on Dr. Thomas Goreau’s findings. Biochar and rock powders can provide major, cost-effective, atmospheric CO2 sinks to reverse climate change through natural solutions. The most effective use of each material is mixed with the other to maximise synergies for increasing soil productivity and reversing climate change.

In New Zealand, a country with inherently fertile topsoil, carbon losses are occurring at depth under NPK fertilised pastures, due to the inhibition of the sequestration pathway. Alternative practices have been either dismissed or ignored by establishment science.

Biochar is a carbon store that holds water and nutrients, and they must be added to it, so rock powder is a perfect complement.

Raw biochar is ineffective and can last perhaps 1000 years in the soil. Biochar-rock powder mixtures increase root growth and increase the release of underground respiratory CO2 and organic acids, which further accelerate rock powder weathering that releases essential nutrients, which Biochar stores and makes available to plants.

Carbon storing

While biochar does contain high levels of carbon, there remains uncertainty as to how long that carbon will persist in the soil following application.

Soil texture plays a key role in determining the persistence of biochar carbon. Biochar becomes stabilised in the soil by interacting with soil particles.

Clay particles have more surface area for biochar to interact with and are therefore more effective at stabilising biochar.

All agricultural soils, even sandy ones, have some clay particles.

Biochar and rock powder combinations increase both the rate at which climate and fertilisation benefits occur, and the duration of those benefits for both plant nutrition, and carbon removal by recycling carbon and nutrients to accelerate production, biomass, and biodiversity.

The basic rock weathering chemical reaction is:

CO2 + rock minerals = bicarbonate anions + cations (+ silica unless mineral is limestone).

Biochar carbon will remain in the soil for a very long time, but bicarbonate will not be stored in soil unless climate is so dry that limestone nodules do not precipitate out of soil solutions.

For people and planet

Unused bicarbonate, cations, and silica are dissolved and ultimately flushed into groundwater, rivers, and the sea, which accumulates bicarbonate until the carbon is removed biologically and stored as sedimentary organic carbon and limestone, which are the long-term sinks.

Rock powder and treated Biochar used together minimise nutrient and soil loss and maximise environmental benefits to people and planet.

Kiwi Fertiliser has excellent inexpensive rock powder and microbe activated biochar that can be mixed in proportions to suit all circumstances.