Today, we are more aware and proactive about soil erosion than ever before. Rumor has it that we only have 60 years of soil left. Is this true? If so, it is the same as losing 30 soccer fields of soil every minute. How is this possible?
As you may know, we have written about why soil is so important. We need it to grow our food, clean our water, and recycle CO2. 11% of our entire Earth is used for crop production, which we need soil to complete. Yet, we still take soil for granted. Let’s dive into why we are losing soil and how we change this trajectory.
According to the Food and Agriculture Organization of the United Nations (FAO), 33% of the world’s soil is moderately to highly degraded, or worn down, due to erosion by wind or water, drought, loss of soil or organic carbon, loss of biodiversity, destruction of ecosystems, habitat destruction, and pollution.
The World Wildlife Fund estimates that, because of degradation, half of the topsoil on Earth has been lost over the past 150 years. This is critically important because it threatens our ability to provide food for a growing population and jeopardizes the quality of our environment. Soil is a finite resource…its loss and degradation is not recoverable within the average human lifespan. Unless we drastically change our ways.
The USDA’s Natural Resource Conservation Service explains managing soil health, or improving soil function, as “mostly a matter of maintaining suitable habitat for the myriad of creatures that comprise the soil food web.”
This agency has developed four primary drivers of soil health to improve soil function:
- Disturb the soil as little as possible
- Grow as many different species of plants as you can
- Keep living plants in the soil as often as possible
- Keep the soil covered all the time
What is stopping them from achieving this state of soil health is industrial agriculture, which is cultivating crops on a large-scale by the use of intensive actions and chemical fertilizers.
Dr. Bill Robertson, an expert on soil restoration and professor of Crop, Soil, & Environmental Science at the University of Arkansas states, “soils are different everywhere you go…I grew up around Lubbock, Texas and I went to school in College Station, and the soils are different in both places.”
He says that this was even the same in 1995 when he moved to Arkansas. “That was my first experience with soils that have low organic matter and are pretty weathered. In Lubbock, when it would rain I’d sink down way past my ankles, but here in the mid-South with the types of soils we have, a lot of times after rain you don’t even leave any footprint in the soil.”
Why is this happening?
According to the FAO, there are many reasons why we are losing our soil, from erosion, poor farming practices, rain intensity, and wind. Even though we have learned a lot from the days of the Dust Bowl, we have not completely adopted best practices everywhere.
Tilling the soil with a tractor works crop residues and turns over the soil. While initially it aerates and fertilizes, in the long run it causes great damage to the soil. It changes the natural balance of the soil, leaving it dry and compacted so that it can’t support microbes like healthy soil can.
Compacted soil reduces airflow, water filtration, and impacts root growth. Remember, we need these microbes because they act like a fertilizer in the soil. No-till farming allows the crops to decompose into the soil and prevents erosion via wind or water.
Overgrazing by cattle is another reason we are losing soil because it weakens plant growth. A lack of plant growth reduces root mass in the soil, which in turn increases runoff and causes high soil temperatures.
What’s the solution?
One solution is to plant a cover crop, which is planting a particular crop specifically to improve soil quality. By doing this, the cover crop can help feed soil microbes and act as a sort of “glue” to hold them together while the soil rebuilds its microbiome. A second solution would be to introduce root systems. By doing this, the structure of the soil improves because space becomes available for air and water to regenerate the soil.
Dr. Robertson has begun to implement cover crops in some of his side-by-side fields. He says, “in fields where there are cover crops and that are fed soil microbiomes – they can hold 6-8 inches of rainwater per hour.
Conversely, bare, tilled fields only absorb ½ inches an hour.”
According to his research, for those crops that had a 1% increase in organic matter in the soil and added microbes, there is almost an extra inch of water retention per hour. This tells us that by improving the microbiome in the soil, it’s possible to reduce the need for irrigation, and, in return, build healthier, more resilient crops and boost yield without increasing cost.
It makes sense and further supports our point of why industrial agriculture is so detrimental to our soil. As natural microbes and bio-pesticides are absorbed into the soil, taking the place of chemical fertilizers and pesticides, they are better able to support robust plant growth. This leads to bigger yields, better resistance to pesticide stress, and an all-around healthier ecosystem.
“We can work against Mother Nature for a while,” he adds, “but after a while if we can just figure out how to work with the natural process, life is much simpler for everybody.” He continues with, “A lot of farmers treat their soil like they’re building a house and then tearing it down, improving soil structure but then coming in there with deep aggressive tillage and destroying all they built. You never get anywhere doing that.”
“Making” healthier soil
Farmers are also taking steps to ensure healthy soil every day. By increasing the organic matter in soil, you can improve its long-term health and performance. Similar to how you drink and eat pre- and probiotics to improve your gut health, farmers incorporate organic matter, such as crop residues, animal manure, compost, cover crops, and perennial grasses and legumes to feed the microbial community in the soil.
Soils deliver ecosystem services that enable life on earth (FAO)
Researchers also agree that soil health improves through diversified crop rotations, minimal soil disturbance (no-till and reduced tillage), and the use of cover crops. These practices are the basic principles that underpin conservation agriculture. As a result, farmers are sequestering more carbon, increasing water infiltration, improving wildlife and pollinator habitat—all while harvesting better profits and often better yields.
The good news is that there is a worldwide effort among government agencies, NGOs, and food and agricultural companies to provide education, research, and funding to farmers, ranchers, and landowners to help improve, manage, and sustain healthy soils.
Global status of human degradation of soils (FAO)
For too long, we have cared too much about what the soil can do for us, and each year it grows a little more tired, depleted, susceptible to pests, disease and water shortages, and we are all responsible. It is up to us, farmers, ranchers, soil scientists, legislators, and consumers, to invest in our soil once again.
How are NGOs helping?
The Nature Conservancy identifies three main reasons why soil conservation is critical:
- Fighting climate change: Soil contributes to the recycling of CO2 in our environment because it contains double the amount of carbon than our atmosphere. Soil degradation leads to a decrease in soil maintenance of CO2, which, in turn, will act as a barrier to fighting climate change.
- Sustainable food production: We know that healthy soil is crucial to agriculture and crop production. When soil becomes lost, unhealthy, or eroded, this stands in the way of achieving sustainable food production.
- Protecting the habitat and biodiversity: We know that soil regulates water, but when erosion occurs, this can cause a loss of nutrients in the soil and an excess of nutrients in water systems. This could lead to problems in water diversity and can even negatively impact the water that we drink every day.
This is why the Nature Conservancy prides itself on being an advocate for soil and implements different practices including, restoration of biodiversity, carbon sequestration, lower sedimentation, and crop productivity.
The World Wildlife Fund is known for being advocates for animals and nature, but they are also advocates for the soil, too. Soil erosion leads to an increase in infertile land. An increase in demand for food production has led to the conversion of natural vegetation in forests and grasslands to cultivating crops in man-made farm fields and pastures.
The World Wildlife Fund says this is problematic because agriculture, “often cannot hold onto the soil, and many of these plants, such as coffee, cotton, palm oil, soybean, and wheat, can increase soil erosion beyond the soil’s ability to maintain itself.”
The Bottom Line
Our soil is precious now more than ever before, and the loss of this critical resource will lead to catastrophic effects in our food and ecosystem - ones that we cannot afford right now. We must implement practices now to ensure that our soil is healthy and will be around for a long time.