The soil microbiome is crucial to the health of our planet and crops. The soil microbiome is all the living things in the soil—from earthworms to helpful microbes—that help preserve soil health and contribute to biodiversity. Unfortunately, decades of using chemical pesticides, herbicides and fertilizers have taken their toll on soil health. Tilling, plowing and a lack of organic matter further destroy the soil microbiome. This leads to crops with fewer nutrients, soil erosion and even failed crops.
A better soil microbiome, on the other hand, might just save the planet. Here’s an overview of how repairing the soil microbiome can help improve the entire ecosystem.
What’s in the microbiome?
Soil microbiomes contain billions, even trillions of microbial organisms in the soil. Much like the human gut microbiome, these organisms can “digest” plant exudates and provide nutrients to the soil. When the microbiome is healthy, plants thrive. When it’s harmed by synthetic ingredients (or antibiotics, in the case of the human gut), nutrition and health suffer.
Our soil has multiple layers (also called horizons). The microbiome is mostly in the top six inches of soil, and each teaspoon should contain about 50 billion microbes. They’re invisible to the human eye, but they do the heavy lifting when it comes to soil health.
Soil microbes have a symbiotic relationship with the plants growing in the soil. Plant roots exude sugars, enzymes and other organic compounds. The microbes feed off the exudates and eventually return nutrients like potassium, nitrogen and phosphorous to the soil. Therefore, the better the soil preservation methods, and the fewer synthetic chemicals are used, the better the soil will be for plant growth.
To tell if your soil is healthy, look at its color and texture. An optimal soil full of organic matter should look dark brown, and will have plenty of visible plant and animal presence. For example, earthworms help maintain a healthy microbiome, so their presence is a good sign.
Next, check the texture. Ideally, there should be a varied texture. This is usually made of air, water, organic matter, sand, silt and clay. You can also test the texture by seeing how well it retains and drains excess water.
Why is the microbiome important?
A good microbiome isn’t just good for the microbes and plants. It’s also crucial to protecting the environment. It’s no secret that climate change is seriously harming our planet—but good soil health can actually fight against it.
One of the reasons regenerative farmers caution against plow and tilling is because it releases carbon into the atmosphere. A healthy soil microbiome, however, can capture more carbon from the atmosphere. The more carbon that’s sequestered underground, the less is trapped in the atmosphere, causing global warming.
Second, a soil microbiome supports healthier plants. The more organic matter in the soil, the more likely it is to have plenty of healthy bacteria, nematodes, fungi and earthworms. Plants are better able to absorb nutrients and water, leading to healthier plants. The healthier the plants, the less likely farmers will need to use harmful chemicals, pesticides and fungicides. Microbes proactively fight off disease—and healthy soil encourages better water retention. This saves farmers money on synthetic chemicals, water and more. Furthermore, they’re more likely to get a better yield and more nutritionally dense crop.
Improve the microbiome in your own backyard
There are a few ways you can improve your own soil health. Consider purchasing a soil testing kit at your local home improvement store. This can tell you the soil’s makeup and which nutrients may be lacking.
Composting is a great way to create rich soil full of organic matter. Don’t forget to use clippings as mulch, either—general yard debris is sufficient to replenish the soil with nitrogen, and allows helpful fungi to thrive. Allowing plant matter to naturally decompose will also help provide nutrients to the soil microbiome.
Finally, if you have a fruit or vegetable garden, consider practicing cover cropping. Choose crops that grow at different times of year, with different root structures. The additional organic matter helps replenish the soil, and different plants return different nutrients back into the ground. It also helps prevent erosion, supports water retention and traps more carbon underground.
The bottom line
Better soil health is key to saving the planet—and it’s something you can accomplish in your own backyard. In addition to supporting regenerative farms, why not make this the season you finally start introducing these practices into your garden?
