What Would Happen if the World’s Soils Disappeared?
The United Nations designated December 5th as World Soil Day to raise awareness about the dangers of soil loss. Youíve likely heard about the environmental importance of soils. But how important are they, really? Letís take a quick look at how losing our precious soils would impact the world.
Could soil ever actually run out?
Yes. If we continue to harm and degrade topsoil at the current rate, itís estimated that the world could lose all its topsoil within 60 years.
Topsoil is the uppermost layer of soil on the surface of the earth. Itís the most fertile type of soil that typically contains lots of nutrient-rich organic matter from broken down plants and other organisms. Topsoil is also alive with beneficial microbes, fungi and critters like earth worms, which feed on the organic matter.
The deeper layers of soil beneath the topsoil are not nearly as rich. They are primarily made up of decomposing rock that provides the raw material for future topsoil as well as a substrate for deeply rooted plants to anchor in.
If the delicate ecosystem within topsoil is disrupted, it will essentially die. Plants canít grow in topsoil that doesnít have abundant organic matter and thriving populations of microbes.
Modern agricultural practices often use chemical fertilizers instead of organic matter. This does not feed the soil. It only provides a quick blast of limited nutrients that the plants soon consume. Whereas, plant debris and other organic matter will slowly break down and provide ongoing nutrition for growing plants and soil microorganisms.
The organic matter content that was once naturally high in topsoil is becoming more and more depleted as industrial farming practices continue. Due to this, topsoil is being lost between 10 and 40 times the rate at which it can be naturally replenished.
If this continues, agricultural soils will become less fertile and it will be more difficult to grow food. In areas where this is already happening, forest and wild areas are often being destroyed in order to make more agricultural land. Deforestation like this reduces organic matter in the soil even more, making the problem worse.
The extreme outcome of topsoil degradation would be widespread food shortages because depleted soils canít produce enough crops to provide food for everyone.
Impact on Water
Healthy topsoil will naturally retain water. Organic matter helps to maintain a good structure within soil that can absorb and release water as needed by the plants and surrounding ecosystem.
A few issues can start when topsoil becomes degraded. Flooding is perhaps the most dramatic result. When a landscape canít hold water, rainfall can only run off the surface and eventually wind up in the ocean. It will also cause erosion and take a great deal of soil with it.
Poor topsoil also creates a need for more irrigation. Many parts of the world already have water shortages, so an increased pressure on the local water supplies could lead to serious problems.
Plant and Animal Losses
If we lost the health of our soils, significant amounts of wild plants would die off around the world. This would clearly be a massive blow to biodiversity, habitat for animals and food sources. But it could also have a significant impact on climate change.
Plants naturally take in carbon dioxide and release oxygen. This is the primary way carbon is removed from our atmosphere. If plant populations collapsed around the world, there could be a huge increase in the amount of circulating carbon.
Another issue is that all living things release carbon when they die, so any large-scale plant and animal die-offs would produce carbon as the organisms decompose. High levels of carbon dioxide in our atmosphere have already been linked to climate change and global warming. Mass die-offs would only add to this problem and potentially lead to more severe climate change.
How can we stop all this from happening?
Plant more plants. This is a vital step towards helping the worldís soils. More plants will create more organic matter, which will feed more soil microorganisms and keep soils thriving. You can start in your backyard or volunteer with an organization that reclaims and replants degraded areas.
Learn about soils. A lot of the damage done to our soils has been out of ignorance or simply taking whatís under our feet for granted. But the more we can all learn about soil, the better weíll be able to take care of it.
Minimize hard surfaces. Large areas of pavement or other hard surfaces cause increased soil erosion around the edges and create soil dead spaces underneath. Consider making driveways, decks or sidewalks with paving stones or other materials that allow water to flow through them and the soil underneath to breathe.
Make a rain garden. This is a shallow depression you can create in your yard that will capture excess rain water and prevent soil erosion. You can plant moisture-loving plants in your rain garden, or leave it to provide water for animals.
Support your local farmers. Small-scale agriculture is often better for the health of soil. Many small farmers take the health of their land very seriously and promote fertility by non-chemical, sustainable means. Get to know the farmers at your local market and ask how they support their soils. Or better yet, go to visit their farms and check out the soil yourself.
Recycle human waste. It may be a solution no one wants to talk about, but a huge amount of organic matter that could go back into our soils is currently being flushed down the toilet. This has prompted a movement to make use of whatís known as humanure, or human manure. The Humanure Handbook by Joseph Jenkins is a great place to start if youíd like to explore this option.