As humans, we can do almost anything we put our minds to, but we can’t make soil. Our soils have developed over millions of years of erosion with the support of millions of species. From moles and mites to the microscopic, soils are not only full of life – they make life! And yet human activity is rapidly degrading our soils to the point that 90% of it could have degraded by 2050 if nothing is done. So, what can we do to protect and revive the little things that make life possible?
Caroline Heinzel and Samantha Ibbott report.
Soil is life
Our soils are alive – or at least they should be. Soil ecosystems host 25% of our planet’s biodiversity, regulate water and carbon cycles and provide 95% of the food we eat. We rely on soil, but we can’t make it – at least not quickly. But there are plenty of other species that can.
In just one teaspoon of topsoil, there are around 1 billion individual microscopic cells, and around 10,000 different species from four broad categories: bacteria; protozoa; fungi; and viruses. As the Food and Agriculture Organisation of the United Nations (FAO) has rightly pointed out, soil microbial ecosystems are likely the most genetically diverse communities on the planet. And together these organisms form the basis for life itself.
There can be no life without soil and no soil without life: they have evolved together.Charles E. Kellogg (1938)
Head of the Soil Survey in the US Department of Agriculture from 1934 to 1971
By decomposing and recycling organic materials, removing toxins, and ensuring soil integrity, these tiny organisms – alongside the other larger creatures – create the very soil they live in. They are part of a vast, complex and delicate ecosystem, an underground jungle of truly galactic proportions, and form relationships with each other and/or the plant roots surrounding them.
It’s an eco-SYSTEM
To date, only 1% of soil microorganisms and around 10% of small soil organisms have been identified. This vast ecosystem is still a mystery to us, but we do know that, as with any ecosystem, there is a community of organisms that interact with each other and their environment.
Take dung beetles. These creatures burrow up to a metre underground, carrying nutrients with them. These nutrients are then picked up by earthworms – important engineers in this subterranean world – burrowing through the soil, creating up to 8,900 km of channels per hectare which allow for the movement of water, air, and nutrients. These nutrients support the growth of other species, such as water bears, springtails, and nematodes, which then become prey or predator for others. Fungi also feed on such nutrients and form beneficial associations with plant roots, enhancing the plant’s uptake of nutrients, supporting disease resistance, and improving its resilience to environmental stresses, such as floods and droughts – about 80-90% of all plants have a symbiotic relationship with fungi. The bigger the plant grows, above and below ground, the more beneficial this is for the creatures in the soil and when it dies or is eaten by a grazing animal, the organic matter is recycled back into the ground and the system starts all over again.
The organic matter needed for soil to be healthy would not exist without the collective work of all these organisms. Without them, our soils would be biologically dead, nothing more than a layer of rock dust and water in which plant and animal life cannot thrive. Even changes in the soil community impact the soil’s ability to grow food, help regulate climate, filter and absorb water and provide habitat.
Crumbling to dust
We can’t make soil on our own, but we can and do destroy it. 60-70% of soils in the EU are unhealthy and around 1 billion tonnes of soil are washed away by erosion each year. Intensive agriculture, urban expansion (resulting in ‘soil sealing’), climate change, and pesticide use are just some examples of the human activities that have resulted in such large-scale soil degradation – where healthy soils turn to dust.
This is not just devastating for the creatures that live in the soil. Current estimates indicate that soil degradation comes with substantial costs, ranging from €50 billion to €97 billion. And that’s excluding the currently unquantified cost of disrupted green water cycles (the water held in plants and soils).
Soil organisms play an additional crucial role in quietly combating climate change. As the largest terrestrial carbon sink, they contribute to essential processes that influence greenhouse gas dynamics and carbon sequestration and increase the overall resilience of ecosystems to extreme weather events.
Want to know more about the carbon sink beneath our feet?
Chemical dependency and the war on life
We know that we rely on soil organisms to grow healthy crops. And yet, traditional intensive agricultural practices – such as the use of heavy machinery, ploughing, and fertiliser and pesticide use – damage and disturb soil communities. We know that excessive use of fertilisers can lead to a loss of soil biodiversity, but since 2010, the amount of mineral fertilisers used in the EU has increased by more than 8%. We know that only a small amount of the pesticides applied reach their intended targets and the rest moves into the surrounding environment, contaminating ecosystems and killing soil life, and yet the European Commission’s proposal to regulate the use of pesticides is under huge attack.
Depleted and badly managed soil cannot provide the macro and micronutrients for plants (and in turn the animals that eat them – ourselves included!). Applying ever more synthetic fertilisers is not the solution. We must support soil communities. Only healthy soils produce healthy food. And dead soils produce none.
Thriving soils, thriving farmers
Soil health degradation could lead to a 25% decline in food production by 2050. But by increasing soil biodiversity, we could grow an additional 2.3 billion tonnes of produce globally each year. We must recognise that the resilience of our food system relies on this ecosystem, especially in the face of climate change and the increasingly extreme weather patterns that come with it. Many farmers don’t need to imagine this – it’s here already.
If soil organisms are allowed to work their magic, it is amazing how efficiently and tirelessly they perform their daily tasks – and all for free! Rather than ploughing through, uprooting their home and drenching them with large amounts of toxic synthetic chemicals, we should support them. Numerous studies of organic farming systems have shown a greater abundance of soil biodiversity and activity.
Research farms, such as Alfred Grand’s in Austria, act as great ambassadors for the benefits of healthy soils. Alfred works hand-in-hand with soil organisms on his ‘worm farm’. By feeding fresh compost to his earthworms, and the microorganisms that live with them, he receives rich humus in return – a thick brown or black substance that remains after organic matter has decomposed. Alfred then coats the seeds he plans to plant with this liquefied humus and the plant roots transport the nutrients and microorganisms they received from the humus deep into the ground, supporting the soil microbiome and increasing crop yields.
It is possible to reverse the degradation of EU soils. In 2021, the European Commission presented the EU Soil Strategy for 2030, setting out a framework for the protection, restoration and sustainable use of European soils. As part of this strategy, the Commission committed to a legislative proposal for a Soil Health Law, which is expected to be published in June this year. If properly designed, it can give soils a strong legal framework that air, water and marine environments have had for some time, ensuring that they continue to perform their ecological functions, on which we rely so heavily.
To support with this, we’ve provided clear recommendations for EU decision-makers on how an ambitious Soil Health Law can be designed to accomplish its mission of achieving healthy soils by 2050. In this article, we’ve explored how soil organisms contribute to essential soil ecosystem services, and therefore advise that the EU put this at the core of its policy.
The definitions of both soil health and soil health indicators must explicitly address soil biodiversity, and a comprehensive EU-wide harmonised soil monitoring system must be established to measure the true extent of soil health degradation.
In addition, we believe that this law should include legally binding targets for achieving soil health. This would allow for the process to be tracked and will hold Member States accountable if they do not meet their commitments. In addition, Member States should clearly indicate, in the form of regional plans, where the key zones of soil degradation lie, and how they intend to address them.
If you’d like to learn more, we recommended checking out the additional work that has been done by the Soil Health Law Coalition – including NGOs, scientists and farmers – all of which called for an ambitious and progressive Soil Health Law in an Open Letter to the European Commission in March 2023. The Coalition also tackled the issue of soil biology and its role in the Soil Health Law in a Joint Position Paper.
Photo credit: Alfred Grand, GRAND FARM