Should we stop treating soil like dirt? By Ross Primmer

Last week a headline in The Guardian caught my attention, ‘Indian mystic Sadhguru on 100-day motorbike mission to save soil’. The story itself focusses on how Sadhguru, one of India’s best known spiritual leaders and a  motorbike enthusiast, who is embarking on a 100-day motorbike journey from London to India to raise awareness about nature’s most important and undervalued resources – soil.

Soil is amazing stuff. Healthy soil is fundamental for agricultural production and fundamental to life on earth, however, its benefits do not end there. Soils are a key part of the carbon cycle and one of our most important carbon sinks. They benefit biodiversity and even provide more climate resilient landscapes, which are better able to cope with extreme weather events such as floods and droughts.

A 2019 report by the Environment Agency raised a number of key findings about the state of soils in the UK, namely:

  • Soil degradation is estimated to cost the UK £1.2 billion per year (in 2010).
  • 4 million hectares of soil are at risk of compaction in England and Wales – increasing flooding risk.
  • 2 million hectares are at risk of erosion in England and Wales.
  • UK soils currently store around 10 billion tonnes of carbon (roughly 80 years of annual UK greenhouse gas emissions).
  • Intensive agriculture has caused arable soils in the UK to lose about 40-60% of their carbon.
  • Reversing soil degradation and restoring fertility by 2030 is an aim of the government’s 25yr Environment Plan.

Research from The John Innes centre estimates that in optimum conditions, in a temperate climate, it can take 200-400 years for 1cm of new soil to form (in the tropics this can be a bit faster). The complex processes which allow nutrients to become available can take significantly longer, the same research estimates that it takes 3,000 years to make soil fertile.

Throughout human history we have been masters at managing our soil to maintain its productivity. For centuries and perhaps millennia farmers practiced a range of techniques from crop rotation to agroforestry and the creation of terra preta, by farming communities in the Amazon basin between 450BCE and 950CE. Your local allotment is also likely to have its fair share of “no dig” advocates in it.

Indian mystic Sadhguru is undertaking a 100-day motorbike mission to save soil.

However, modern industrial agricultural practices, reliant on large machinery and the application of pesticides and fertilisers, often actively degrade soil. In 2014, the UN Food and Agriculture Organisation reported that global soils were degrading at such a rate that “we only have 60 harvests left”.

The reality behind this headline is more nuanced. Soil quality is highly localised and dependent on a range of environmental and human factors, including weather, climate change impact, agricultural practices, and land use change. When soil is degraded it is more susceptible to erosion, which can lead to loss and ultimately desertification. In short, we need to think in a more sustainable way about how we use and manage soils and the number of harvests we have left is up to us!

Perhaps Sadhguru provides a solution in a more prophetic way. He thinks that we should think about soils as a living organism (he has a point, one teaspoon of healthy soil contains more microbes than there are humans on earth). We can enrich soil by adding organic matter, which in turn improves structure and leads to a whole host of benefits from better productivity to water retention and carbon absorption.

The state of our soils might often feel a long way from modern life, but the fact is we are intrinsically connected to them. Sadhguru wants to get us all talking about soil over next 100 days – why not dish out a bit of dirt in your next conversation!

For more information

Ross Primmer
Consultant
[email protected]