Soil as Solution

Written by Bronwyn Simmons

Driven by greed and ignorance, we have pushed our environmental home to the point where it pushes back, wreaking havoc on us with natural disasters and famines. Yes, fossil fuel use has greatly contributed to global warming, but a large amount of the carbon that we’ve released into the atmosphere comes from degenerative agricultural practices. Humans have failed to see soil as a living super-organism and an integral part of the carbon cycle; instead, we’ve treated it like dirt. Agricultural practices such as improper grazing, excessive plowing (tillage), toxic chemical use, and mono-cropping have led to soil erosion, degradation, and ultimately desertification. As we’ve lost carbon in our soils, water storage capacity and infiltration rates have decreased, as well as food nutrient levels. This is a bleak outcome, but nature already has the solution.

Plants perform photosynthesis, which takes carbon out of the atmosphere and puts it back into the plants. Plants then exude some of the carbon in the form of carbohydrates through their roots in order to feed the microbes living in the soil. Plants do this in exchange for nutrients that the microbes make available by producing enzymes and acids that can literally mine the sand, silt, and clay that make up part of what we call soil. Although we have farmed carbon out of our soil, we can build it back up with regenerative farming practices: nature’s form of carbon sequestration.

For example, before humans began to domesticate animals, ungulates like bison and other grazing animals roamed the land. These animals would move in herds, constantly moving on to fresh forage, leaving a well-fertilized path behind. Predators such as mountain lions, wolves, and bears kept the herds moving and packed together. Birds followed the herds, feeding on fly larvae, and dung beetles moved the natural fertilizer into the ground. This fertility loop of grazing and fertilizing supported a great diversity of plants, including deep-rooted perennials. The constant photosynthesizing capability of plants pumped carbon into the soil, feeding the microbes, which in turn made available the necessary nutrients for plants to thrive.

As humans have separated animals from fields in an attempt to maximize profits, current rangeland practices turn the soil into desert. Over 75% of land is already degraded from desertification. We have killed off predators and fenced our landscapes, which means range animals now stay in one place. We removed our cattle from our cropland and put them in pastures where they now overgraze on one area of land. These practices have killed our perennial plants, leaving only annuals to grow. Annuals have shorter roots, are less able to access water, and photosynthesize for shorter lengths of time than perennials. This leaves the soil bare without green vegetation, which does not feed the microbes, decreases water infiltration and water holding capacity, and increases erosion, ultimately leading to desertification.

Long ago, rain was the only water plants needed, and the soil behaved like a giant sponge due to its good structure and high organic matter content. Now, soil is unable to hold and absorb as much water because the organic matter has oxidized, meaning carbon has been released from the soil into the atmosphere from current agricultural practices. Our soil is no longer sponge-like, allowing runoff and erosion to occur. Our soil is bare, with no plant coverage, due to tillage, mono-cropping, and improper grazing techniques. This allows the water to evaporate instead of containing it under a layer of covered earth. When it rains, our soil cannot hold the water; thus, we must irrigate more and more. It is impossible to replenish our aquifers since rain no longer infiltrates the land the way it used to. Most of our aquifers are being drained at faster rates than they can refill. Plus, they are now full of toxic chemicals from our use of antibiotics on crops. If we looked at the underlying issue of low carbon content in our unhealthy soil, we could work to increase water-storage capacity by increasing organic matter, instead of simply using irrigation and depleting our water supply. For every 1% increase of soil organic matter, soil can hold up to 27,000 gallons more water per acre.

Implementation of regenerative farming practices requires un-learning much of what conventional farmers have been taught. For example, over centuries, plowing (or tilling) our fields has been the normal way to prepare soil for planting. Unfortunately, tillage disrupts all of the biology that is critical for the soil microbiome. The mycorrhizal networks, which connect plants and fungi underground, have been destroyed. Imagine that your home is bulldozed ten times per year, and each time you must rebuild it again. That is what tillage does to the life that makes up the soil microbiome. It also oxidizes soil organic matter (carbon) into the atmosphere and breaks up soil aggregates, the particles of sand, silt, and clay glued together by soil microbes. These aggregates play an important role in gas exchange and water storage and infiltration.

Our soil used to have lots of species of plants, all with different root exudates and root depths, which fed all sorts of microbes. Now, we employ mono-cropping, which means one crop only has one kind of root exudate and root depth, which feeds far fewer species of microbes. Using a diverse mix of cover crops is a good place to start; once a crop is harvested, it’s important that another living plant takes its place. Soil is at its healthiest when it hosts multiple species of plants. Each plant has the ability to attract different microbes, and biodiversity thrives in these conditions.

Further, farmers use antibiotics such as herbicides and insecticides to protect their crops. Glyphosate, the active ingredient in the herbicide Roundup is the largest antibiotic in use in conventional farming. Would you eat these poisonous -cides? If the answer is no, then why is it rational to eat fruits and vegetables that have been treated with them? Pesticides have been linked to cases of cancer, as well as to many neurological diseases like Parkinson’s. Chemicals in fertilizers are also destructive to cell biology. Now our soil contains a fraction of the nutrients it used to, and our food is less healthy for us. Similar to the epidemic of antibiotic resistance, our wars on weeds and bugs have created superweeds and superbugs. These super weeds and super bugs develop a resistance to antibiotics, and cannot be killed by regular doses of herbicides and pesticides, so even more antibiotics must be used to combat them. Superweeds and superbugs are products of overdosing our plants with antibiotics.

Instead of simply spraying a diseased plant with an insecticide, which makes the soil even more unhealthy, a farmer instead could ask the question, “Why does my plant have aphids?” and attempt to find the root cause. A plant that makes complete proteins and good nutrients does not attract destructive insects; rather, these bugs sense when a plant is unhealthy, and then they attack. Plants will become insect resistant when their soil is loaded with diverse microscopic organisms that create a healthy environment.

Instead of using antibiotics, regenerative farmers focus on methods like compost, which are more probiotic. Bringing animals back onto croplands, using diverse species of cover crops, no or low till, and keeping soil covered can all be thought of as probiotics for the soil. These methods can increase the amount of carbon content in the soil. So, what happens to soil when it has a large carbon content? Only good things: It increases soil fertility, plant nutrient levels, and water storage capacity and infiltration rates, and builds soil. Currently, our soil carbon content (organic matter) is down to about 1-2%. If we could increase it, the entire ecosystem above and below ground will improve.

How can we implement regenerative farming practices to solve climate change by sequestration of carbon? We can start by bringing our animals back onto the fields so they can restore and fertilize our plants and eat nutritious food, instead of confining them to live in cages and feeding them genetically modified corn and soy. An integrated system like nature intended, where animals graze on the land, move across it, and fertilize it, is essential. Bringing our animals back onto our cropland will create a thriving biodiverse environment with high nutrient content. We must utilize controlled grazing, however, meaning: allow a herd to only eat about 50% the forage before moving it to another area. This creates more plant biomass, makes the crop recovery period shorter, and maximizes photosynthetic capacity.

Of course, we must cease to use any antibiotics, allowing the soil to thrive without destroying its inhabitants. We must minimize soil disturbance to protect its function. These practices will restore carbon content, increase water-storage capacity, and replenish our aquifers, reversing desertification of land and sequestering excess carbon from the atmosphere into the ground, essential for mitigating the effects of anthropogenic climate change. Other names for regenerative agriculture that may sound familiar are: agroecology; biodynamic farming; carbon farming; permaculture; holistic grazing; silvopasture. For more information on regenerative agriculture, read Dirt to Soil: One Family’s Journey Into Regenerative Agriculture; The Soil Will Save Us; Kiss the Ground: How the Food You Eat Can Reverse Climate Change, Heal Your Body & Ultimately Save Our World; How Cows Can Save the Planet; Growing a Revolution; Grass, Soil, Hope.