mole emerging from the soil

Soil at the heart of six global challenges

Almost all of the food grown to feed everyone well requires soil. This universal truth has been with humans every step out of Africa and across the planet.

Soil is essential to human survival and well-being, yet we take it for granted. 

Part of this is because the soil is quite robust to the forces of nature and even the machinations of human impacts during the 12,000 years since the invention of agriculture. Most soils can take quite a beating before they show any wear and only collapse after heavy exploitation.

Human ingenuity, technological prowess and a pulse of fossil fuel energy have changed us from a species that lived in nature, fossicking for food and finding shelter where we could to one that lives off nature. We find and exploit natural resources converting them into energy and materials that give us a very different life from our ancestors. Soil has become one of the resources to exploit. 

Soil delivers five essential functions that make it a valuable money machine

  1. Nutrient cycling
  2. Water retention
  3. Biodiversity and habitat
  4. Storing, filtering and transforming compounds
  5. Physical stability and support

These services do not make money, but they make it possible for humans to consistently and predictably grow crops and rear livestock that do.

Whoopy doo. Soil does stuff, and I should care?

Well, perhaps not. 

History tells us that farmers can harness technology and energy to keep using soil to grow food and fibre without needing to know much about these key functions. Instead, they are experts in nurturing crops and livestock under their local conditions. They know what the plants need and when to deworm the sheep. And these skills have been enough.

Food production has grown steadily for centuries, and even with 8 billion people, enough food is grown to feed everyone. Food insecurity is an access and efficiency problem fixed for the time being through economic, social, and political solutions. 

If agricultural production works when the focus is on the crop plant or the livestock with little or no attention to the soil, why should consumers be concerned?

In short, degradation

But for once, we will even ignore that giant elephant pooping on the carpet.

Instead, let’s look at soil as all or part of the solution to six global challenges—food security, water security, climate change abatement, ecosystem service delivery, biodiversity protection and energy sustainability.

These are the big ones, the challenges that will not go away but have to be addressed or human society collapses. 

So let’s see what connection they have to soil.


Food security

The quantity, quality and accessibility of food require that soil is in good shape and functions consistently even when the climate is a bit crook. 

The reality is that soil is still the primary growth medium for almost all human food and several other key resources, including biofuels, various fibre crops and timber.

Food also needs to be nutritious—including a suite of micronutrients—because food security is not just about the amount of food but also about achieving a healthy diet.

Food also needs to be safe. No use growing giant pumpkins in Alabama if they are contaminated with heavy metals.

Even though food security is much more than just production, there is no food security without it.

Essential soil functions for food production 

  1. Nutrient cycling
  2. Water retention
  3. Biodiversity and habitat
  4. Storing, filtering and transforming compounds
  5. Physical stability and support

Essential soil functions for avoiding contamination of food

  1. Nutrient cycling
  2. Water retention
  3. Biodiversity and habitat
  4. Storing, filtering and transforming compounds
  5. Physical stability and support
banquet of Asian style food
Photo by Lily Banse on Unsplash

Water security

Freshwater has always been a critical and often limiting resource for humans. In the hunting and gathering days, people had to live close to streams, rivers or lakes, and when they moved, they needed to know where the springs were in the desert. 

Remarkably they did. Many times local knowledge meant that elders knew where there was a spring or a stream that delivered water even in dry times.

Soil is a sponge. It soaks up rainwater and stores it in the landscape, releasing it slowly to keep streams running. We always underestimate this water regulation property of soil that depends on the soil type, the amount of vegetation cover, and the organic matter in the soil.

Soil also filters the water, reducing contamination.

Essential soil functions for water  

  1. Nutrient cycling
  2. Water retention
  3. Biodiversity and habitat
  4. Storing, filtering and transforming compounds
  5. Physical stability and support
Photo by Luis Tosta on Unsplash

Climate change abatement

Unless you live under a rock or attend QAnon meetings, the issue of human-induced climate change is real and immediate. Acute climate change is with us because of the level of greenhouse gases in the atmosphere. 

In 1800 the levels of CO2 were 283 ppm, and in 2022 reached 421 ppm with a current net annual increase in atmospheric CO2-C of 4.3 Pg yr-1. Methane concentrations have more than doubled, and nitrous oxide levels have increased by 50%. Agriculture and land use change are together responsible for 21–24% of global anthropogenic greenhouse gas emissions

Soil is a huge reservoir of carbon.

Soil organic carbon (SOC) is by far the largest pool of organic carbon and globally contains over 1,550 Pg C, followed by the soil inorganic carbon (SIC) pool (750–950 Pg C) and terrestrial vegetation (600 Pg C) . Therefore, the total soil C pool is about four times larger than the terrestrial vegetation and three times larger than the atmospheric carbon (C) pools. 

Because carbon and nutrients are sequestered in soil and in the plants that soil supports, how soil is managed can mean it is a net sink or source of greenhouse gases. 

Management of soil for climate change abatement can reduce greenhouse gas emissions or sequester carbon, or both.

Essential soil functions for greenhouse gases 

  1. Nutrient cycling
  2. Water retention
  3. Biodiversity and habitat
  4. Storing, filtering and transforming compounds
  5. Physical stability and support
horses grazing on an upland meadow in Mongolia
Photo by Natalia Slastnikova on Unsplash

Ecosystem service delivery

The goods and services humans need from nature are the consequence of other species. Some we eat. Some we use to build our homes or fuel our fires. There are those that we admire. 

Then there are all the species that must be present to clean the air and the water to make life possible. These species moderate and deliver critical ecosystem services, and most of them live all or part of their lives in soil.

Soil provides a wide range of ecosystem services

  1. Nutrient cycling
  2. Water retention
  3. Biodiversity and habitat
  4. Storing, filtering and transforming compounds
  5. Physical stability and support
lush alpine meadow in summer among rolling hills
Photo by Claudio Testa on Unsplash

Biodiversity protection

In a teaspoon of soil, there is dirt (sand, silt and clay) plus some dead plant material, some dead animals and faecal matter and water.

Then there are the organisms, the life that makes dirt into soil: 

  • 100+ million bacteria
  • 150+ micrograms of fungal hyphae
  • 10,000+ protozoa
  • 100+ nematodes
  • 150+ Arthropods (mites, collembola, insects), and 
  • 10+ other invertebrates (earthworms, slaters etc). 

The biomass of the bacteria alone can be the equivalent of 5 cows per hectare.

The taxonomic resolution we are familiar with for birds, mammals, and most plants, is the species. A teaspoon of soil will typically contain thousands of species, many not yet described by taxonomists. Then there is diversity at the genetic level that is so complex that science has yet to get a good handle on its scale.

What is known is that all soil is hugely biodiverse

Soil is the habitat for the largest gene pool and diversity of species (3), which enables plant growth, the recycling of waste and the provision of nutrients affecting food and water security (1, 4).

  1. Nutrient cycling
  2. Water retention
  3. Biodiversity and habitat
  4. Storing, filtering and transforming compounds
  5. Physical stability and support
monkey licking the sweetness from a plastic cup
Photo by Raden Eliasar on Unsplash

Energy sustainability

Humanity has gorged on the near-free fossil energy of coal, oil and gas. But this is a one-time gift from Gaia. Fossil fuel resources are finite and come with externalities (waste and pollution) that the planet cannot absorb. This is why humans have, somewhat reluctantly, set an energy transition in progress.

Over the next decades, society will find alternatives to fossil energy. The use of plants for energy production (e.g. ethanol) is one of the options. Pre-industrial revolution, humans used wood and charcoal for heat and cooking, and with modern machines able to extract oil from seeds, there are other options. These bio-fuels are not direct substitutes for oil, not least because they have a chemistry that corrodes pipes and engines much faster than kerosene, gasoline or diesel fuel, but we will need some of them across the energy transition.

Obviously, growing plants for energy means that they are not grown for food, but they still need land, soil, nutrients and water. The trade-off with food security is acute.

Essential soil functions for plant-based energy

  1. Nutrient cycling
  2. Water retention
  3. Biodiversity and habitat
  4. Storing, filtering and transforming compounds
  5. Physical stability and support
larger solar farm under a blue sky
Photo by American Public Power Association on Unsplash

Solution to six global challenges all need soil

Even this cursory glance from soil level at these six global challenges is telling. It demonstrates how central soil is not just to what is coming but to how humans have managed to become so numerous and, for the most part, prosperous.

Any solutions we find for food security, water security, climate change abatement, ecosystem service delivery, biodiversity protection and energy sustainability must take soil into account. 

Managed well, soil can be an ally. Ignore it and the challenges get deeper.


What sustainably FED suggests

Soil is life.

Take soil for granted, and humanity is doomed to collapse. 

Pay attention to the soil to manage it wisely, and it can sustain the current and future populations of people.

But just saying these things and listing a few obvious reasons why soil is at the heart of global challenges is not enough.

Soil has to become as important to each consumer as their pay packet. They have to understand that without healthy soil, there is no food, no clean water and no pay. The very foundation of people’s lives is at risk if we let soils degrade.

The reality is that fixing challenges like climate change and biodiversity loss cannot be done without healthy soil but fixing them becomes irrelevant if there is no food.

So when people say climate change is the critical issue of our time, nod wisely. They are right it is critical but not the critical issue. 

In our view, that goes to maintaining healthy soil.


Science source

Koch, A., McBratney, A., Adams, M., Field, D., Hill, R., Crawford, J., … & Zimmermann, M. (2013). Soil security: solving the global soil crisis. Global Policy, 4(4), 434-441.


Hero image from photo by Pixabay

Mark

Mark is an ecology nerd who was cursed with an entrepreneurial gene and a big picture view making him a rare beast, uncomfortable in the ivory towers and the disconnected silos of the public service. Despite this he has made it through a 40+ year career as a scientist and for some unknown reason still likes to read scientific papers.

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