Soil is the foundation of life. This thin layer of the earth supports the growth of nearly everything living on the planet. In fact, 95% of everything we eat is directly or indirectly produced in soil.
Despite the importance of soil to our welfare, many people might not be aware that we're at risk of losing soil to grow food. In fact, scientists say we have ~60 years of farming left if soil loss continues at its present rate.
But, there's hope. Lot's of it. Better farming practices that involve caring for the soil will enable us not just to continue growing plentiful food, but also improve our health and prevent the warming of our planet. Soil offers an accessible and actionable solution to mitigate climate change. What are we waiting for?
What exactly is soil?
Soil is composed of water, air, minerals and organic matter. Soil might look like dirt, but it’s teeming with life. One teaspoon of soil can support a microbiome of one billion organisms This microbiome feeds plants nutrients, carbon, water and supports their growth.
Why is soil at risk?
We’re losing topsoil at a rate that’s 10 to 40 times faster than we’re replacing it. It equates to about 30 soccer fields a minute. Why? Much of this loss can be traced to degenerative agricultural practices (land clearing, overgrazing, overtilling,…) with incentives geared towards yield and production versus maintenance and replenishment. Subsidies often encourage mono-cropping and using chemical fertilizers to maximize output - activities that are depleting our soil.
Can’t we just get more soil?
No. Once soil is gone, it takes a very long time to gain back what is lost. Estimates range from 500 to 1000 years for 1 inch of topsoil to form. So it’s critical that we preserve what we have now.
Where does lost topsoil go?
About 60% of soil that’s washed away ends up in rivers, lakes, and streams, along with whatever chemicals might have been added to that soil. This runoff can fuel the growth of harmful algal blooms, which contribute to loss of marine life and can make drinking water unsafe. It also contributes to loss of biodiversity, including pollinators (like bees), that are critical to our own future.
Why is healthy soil so important?
Soil not only provides nutrients and nourishment to plants (and in turn, us!), but also helps regulate our climate. Here are some of the benefits we receive from healthy soil:
- Healthier food / Healthier people: Healthy soil supports the growth of healthy plants, which in turn feed us and animals.
- Stores carbon: Healthy soil is a carbon sink, helping to store carbon and remove it from the atmosphere to help fight climate change.
- Conserves and cleans up water: Healthy soil acts like a sponge and holds more water than dry, depleted soil. “Each 1% increase in soil organic matter helps soil hold 22,000 gallons more water per acre.” With less water loss, less chemicals enter our water streams.
- Increases flood and drought resistance: Healthy soil hosts more living organisms and absorbs more water during flooding and can maintain water security during times of drought.
- Reduces soil erosion: Healthy soil helps bind particles together and doesn’t wash or blow away as much as depleted soil.
- Fights off disease: The active microbes in healthy soil ward off plant disease
What can we do? How can we support soil health?
Different growers use different techniques to care for soil, but here are some the overarching principles to support soil health:
- Minimize soil disturbance: When soil is churned and disturbed, the microbiome is disturbed. Limiting plowing or tilling preserves a healthier microbiome.
- Cover the soil: Cover crops aren’t necessarily grown to be harvested, but rather are planted to cover the ground after a cash crop has been grown. Instead of leaving the ground bare, cover crops are used to maintain living roots in the earth. Living roots reduce soil erosion and provide nutrients to the soil. (FYI, beans make a great cover crop!).
- Rotate crops: Rotating crops is a way to increase diversity and support soil health.
- Compost - Composting improves the structure and health of soil by adding organic matter, thereby increasing the soil’s water holding properties and reducing the need for pesticides and chemical fertilizers.
- Reduce reliance on synthetic inputs: This is better for the earth and also reduces farmer costs.
- Integrate livestock: Rotational grazing is a means of nourishing the earth and helps reduce the need for chemical fertilizers.
These practices are considered “regenerative” agricultural techniques. There’s a growing movement to encourage farms to transition to these sorts of operations. As consumers, the more we pay attention to how and where our food is grown, the more we can influence market trends, too. From all sides, we can protect, conserve, and support soil health and we don’t need to wait for any magical breakthroughs to make this happen. By supporting farms that actively care for soil, we can preserve this finite and critical resource for our future.
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Foodtank
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Food and Agriculture Organization of the United Nations
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Scientific American
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NRDC
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Regenerative Organic
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Columbia University
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NRDC
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Vandana Shiva
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Rodale Institute
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NRDC