For many people the soil is nothing but dirt. Yet our soils are one of the most precious non-renewable natural resources. It can take up to 1,000 years to create just 1cm of topsoil. The problem is that soil is also one of the most important—and arguably the most neglected—of all our natural resources.
Soil: A Vital Non-Renewable Resource
According to the United Nations, over half (52%) of all food producing soils are moderately or severely degraded due to poor management. Intensive farming and mono-cultural (single crop) production puts soil health at risk by depleting the soil of nutrients, causing soil pollution, altering soil structure and affecting water retention capacity, encouraging soil erosion, and decreasing soil biodiversity.
In the U.S. alone, we’re losing over 1.7 billion tons of fertile soil every year through poor farming practices, such as continuous intensive cropping, over-reliance on artificial fertilizers, soil compaction, and ill-timed soil cultivation. Across the world the current rate of soil degradation is threatening the ability of future generations to meet their most basic needs. Taking urgent action to preserve and regenerate healthy soil is essential for global food security and a sustainable future.
Food Production… and Much More
Healthy soils are the basis for healthy food production. Over 95% of our food comes from the soil, including the vegetables, grain and fruit we directly eat, as well as the forage and grains needed to feed animals for meat, dairy, and eggs. If we don’t protect our soils then our ability to feed the future sustainably will be jeopardized. But healthy soils aren’t just fundamental for producing food: we also need healthy soil to grow plants for fiber (think cotton and paper), fuel (wood and biofuels), and countless medicines.
Wider Ecosystem Services
Soil also provides us with a range of key ecosystem services. Far from being just ‘dirt,’ soil is one of nature’s most complex and diverse ecosystems. More than a quarter of the world’s biodiversity lives on or in the soil—from the tiniest soil-dwelling bacteria to the largest tree. In fact, there are more organisms in one teaspoon of healthy soil than all the people on Earth, including fungi, bacteria, nematode worms, insects, as well as larger creatures like mites and earthworms. This underground ecosystem helps to recycle soil organic matter, supply plants with available nutrients, control pest and diseases, and maintain the soil structure. If you reduce the number of plant species and different rooting systems by farming only monocultures, this can have a very negative effect on soil diversity, as it limits the habitats and food sources for soil organisms, and the natural functions soil can provide.
Healthy soils also work like a sponge, absorbing and holding on to rainfall and therefore reducing the impact of both flooding and drought. Poorly managed, lifeless soils are unable to absorb and hold on to water in the same way, resulting in a higher risk of rapid water runoff (and soil erosion) after heavy rainfall, as well as a lack of water for plant roots in drier weather.
Soil also works to naturally filter and detoxify water as it moves through the soil, ensuring we have cleaner drinking water available in subsurface reservoirs. The over-application or incorrect timing of fertilizer or manure applications can not only kill soil life, but overload the soils natural filtration capacity, leading to runoff and pollution of our water supplies.
Finally, our soils play a fundamental role in controlling climate change. Carbon sequestration is a naturally occurring process where carbon dioxide—a key greenhouse gas—is transferred from the atmosphere into the soil through crop residues and other organic solids. Carbon is a key ingredient in soil organic matter. Plants use sunlight energy and carbon dioxide from the atmosphere (together with water from the soil) to create organic compounds and plant materials. Soil organic matter is created by the natural recycling of the organic compounds in plants, animals, and microorganisms into the soil. This process of “sequestering” of carbon from the atmosphere locks it into the soil as soil organic matter, a highly stable form of carbon, where it can remain for centuries (as long as it remains undisturbed and best management practices are followed).
Scientists now believe that soil carbon sequestration could play a vital role in cutting GHG emissions through capturing and storing atmospheric carbon emissions from fossil fuels and other carbon-emitting activities while enhancing soil quality and long-term agronomic productivity. The Intergovernmental Panel on Climate Change (IPCC)—the world’s leading body for the assessment of climate change—suggests that soil carbon sequestration is the mechanism responsible for most of the mitigation potential.
TAKE POSITIVE ACTION
Well-managed livestock grassland systems, such as those supported by AWA or Certified Grassfed by AGW, have a key role here in helping to maintain healthy soils. Researchers also say that well-managed grassfed cattle systems could capture more total GHGs than they emit, and play a significant role in mitigating climate change. The Food and Agriculture Organization states that “practices that sequester carbon in grasslands also tend to enhance resilience in the face of climate variability, and are likely to enhance longer-term adaptation to changing climates.”