Soil Health for Carbon Storage and Better Food
Many farmers and food companies are turning to regenerative farming practices that build soil health. They do this in an effort to help combat climate change and reduce the impact of agriculture on the environment. The bonus is the food is better too.
Healthy soil helps plants, animals, and microorganisms thrive. It also helps store more carbon in the ground. Soil, which is often overlooked, plays a vital role in helping to keep the planet healthy. It filters water, gives plants the nutrients they need and acts as a home for billions of organisms.
In recent years, conversations about soil health have increased. This is due to global attention on climate, public commitments made by companies, and a growing awareness that our food supply chain is threatened by widespread soil degradation caused by deforestation, unsustainable conventional farming practices and overgrazing.
Healthy soil is rich in organic matter, supporting the biological activity that helps plants grow. This material includes decayed plant residue and humus that decomposes into nutrients readily available to the plant roots.
Root exudates and sugars from healthy plants are transmitted into the soil, where they feed the microbial communities, which then help the plants to uptake the needed minerals and other nutrients. When soil becomes unhealthy, the microbial population gets smaller and less diverse, which makes it difficult for nutrients to be taken up by the plants.
This is why it’s important to cultivate a variety of different crops and cover crops that promote a diverse array of living organisms within the soil. This diversity helps to maintain the microbial populations and increase the ability of the soil to sustain the biological process that keeps the soil and plants healthy, vibrant, and productive.
Healthy soil is a complex ecosystem that sustains plants and microorganisms and enhances air and water quality. A teaspoon of dirt contains more microorganisms than people on earth, and those organisms play a crucial role in maintaining soil health. They make nutrients available to plants, regulate nutrient cycling, improve soil structure and decompose organic matter. They help keep pests and diseases at bay by controlling populations and keeping pathogens from surviving in the first place.
Soil is a living system with an intricate food web that includes microscopic bacteria and fungi, algae and protozoa, nematodes and micro-arthropods, and visible creatures like insects and earthworms, all doing their part to help the plants growing in the soil to absorb nutrients. Food grown in healthy soil not heavily amended with chemical fertilizers contains more nutrients and often tastes better than the alternative. The plants are often more resilient and robust than their heavily fertilized counterparts.
Soil stores carbon, and the amount varies with climate, temperature, rainfall, soil type, and depth. Rich peat soils, for instance, hold about 10% soil carbon; sandy soils can have only half that level.
To store more carbon in the soil, farmers plant cover crops in the off-season that they can then till into the soil in the spring, adding humous and nutrients and storing carbon. Adding an additional species to the crop rotation, such as a grazing mix, further enhances how the microbial community is fed and increases the soil’s ability to transfer carbon from the air to the soil.
Increasing soil carbon takes effort and a long time to build up. But it’s also an easy, natural way to help combat climate change. A recent study estimates that global croplands could store as much carbon each year as the transportation sector emits annually if farmers adopted carbon-friendly soil management practices.