Words by Marion Wood, Chairperson, Soil & Health Association of Aotearoa New Zealand
Did you know there’s triple the amount of carbon in soil worldwide as there is in the atmosphere? This was one of many ‘wow’ moments from the launch of Soil4Climate during Organic Week 2020.
Soil4Climate will do several things at once. It will put carbon from the air back into the soil, support growth in biodiversity, reduce food miles, and build the food resilience of local communities.
But that’s not all. Soil4Climate will also support the wider community of enthusiastic growers. As a result, growers will gather data about what works, spread the knowledge of how to build soil health, and improve our methods of doing so.
This is an open collaborative piece of work that we hope will inspire many.
We’re excited to be underway at two sites. We have begun at Tapu-te-ranga marae in Island Bay and at For the Better Good’s Porirua ‘Edible Earth’ farm (in partnership with WELLFed). We’ve started by bench-marking the current health of the soil at both sites. Over the coming year we will watch as the soil is built up through organic growing methods.
Next we are going to grow the project to include test sites around Aotearoa. This will include urban farms, market gardens, pastoral land, schools and backyard gardens.
We firmly believe that organic growing methods are crucial to mitigating climate change.
So how does it work?
We’re using three sets of measurements to test for carbon and other nutrients in soil health:
The Visual Soil Assessment – which is a hands-on observation of different aspects of the soil. We record how the soil looks, its colour, smell, structure and even the number of earthworms – that bit was great fun!
The soil Microbiometer – here we are measuring the microscopic life in the soil. We know this is vital for plant health and biodiversity. We are looking at microbial and fungal biomass, and working out the fungal to bacteria ratio.
Laboratory analysis of soil content – we send samples to recognized laboratories who analyse the soil. We are measuring things like mineral elements and the carbon content.
Soil4Climate’s initial results will be compared with repeat tests done over time. We expect soil health to improve as we grow on the land and change it’s soil composition through organics.
At the same time we are supporting community growers to connect with each other. This project will support us all to learn new things. And of course we are growing nutritious healthy local kai to sustain community.
How much impact can we have on carbon emissions?
There’s a perception that agricultural soils in Aotearoa can’t sequester carbon. We think this is because the soils that have been examined are mostly microbially impoverished soils. This means the microscopic life like bacteria and fungi have been destroyed. Chemical spraying, tillage, and other land practises are often to blame for this. It means the soils are not functioning naturally or optimally.
For example, regenerative soil consultant Phyllis Tichinin estimates that 1-3 tonnes of carbon can be sequestered per hectare of pasture per year. If this is the case then the pastoral sector alone could make Aotearoa carbon neutral (and even carbon negative) within just a few years. This can happen if we move powerfully now to adopt organic and regenerative practices.
We desperately need more research into this area. Soil4Climate is putting a stake in the ground – literally – to start this process.