Regenerative Agriculture: Putting Carbon in Its Place
Could an answer to climate change be right under your feet?
The presence of carbon in the soil isn’t something most people give much thought to. But as the building block of life itself, carbon not only exists in soil — where it provides nutrition to plants, enhances fertility, and promotes food production — it’s also there in abundance. As you probably recall from elementary school, plants take CO2 from the atmosphere and, through the process of photosynthesis, transform it into carbon. The plant uses much of the carbon to grow and the excess is stored in the soil.
In fact, right now, there’s about 2,500 billion tons of carbon in the soil. That’s almost twice the amount of carbon in the atmosphere and plant life (800 billion tons and 560 billion tons, respectively), combined.
It’s so much carbon that soil is considered a “carbon sink,” meaning it absorbs more CO2 than it produces — just like the Amazon rain forest or the oceans. Scientists say that together, plants and soils currently absorb about 30% of the CO2 emitted by human activities each year. What’s more, soil holds carbon longer than either the atmosphere or vegetation do.
Better Production, More Carbon
If soil is a carbon storehouse, how, exactly, does one get carbon back into it? It’s not like there’s a colossal cosmic sponge that can suck CO2 out of the atmosphere and wring it out underground.
Actually, the answer doesn’t involve much in the way of wizardry at all. It’s really about unleashing nature-made know-how to rehabilitate the ecosystem and boost soil health. It comes down to this: When there are more healthy plants, there’s more photosynthesis and more carbon sequestered.
Ensuring healthy plants and productive soil is what regenerative agriculture is all about. Also known as “carbon farming,” it includes things like composting, grazing management to limit where animals forage and for how long, more careful fertilizer use, planting cover crops, increasing crop diversity, reducing tillage, and using manure rather than chemicals to keep fields healthy. These actions, which are intended to reduce the amount of physical damage to the soil and boost soil biodiversity, come with some pretty significant potential benefits. Above all, they return carbon to the earth to create productive, hardy soils. The land is more resilient, too, less prone to erosion and flooding.
Gauging the Difference
How much of a difference can these measures make? And for that matter, how can you even measure the difference?
Quantifying soil carbon is a multi-step process. And like soil carbon sequestration itself, it’s not done overnight. Truly large changes can take years to become noticeable and it requires repeat soil surveys to get an accurate gauge, but progress can be monitored by:
- Taking a baseline physical sample that indicates the current level and natural variation in soil carbon.
- Estimating the soil carbon potential.
- Performing routine sampling during regenerative agriculture.
- Comparing data against the baseline.
Besides being a tool in the fight against climate change, for companies, carbon soil sequestration offers reputational and economic benefits.
For example, as part of its overall ESG practices, General Mills is paying the North American farmers who produce its oats, wheat, corn, dairy feed, and sugar beets to change their agricultural processes. The consumer products giant is offering one-on-one coaching and soil testing to a pilot group of 80 farmers, and said they believe that those who permanently institute regenerative principles will save money on things like fertilizer and pesticides, making them more profitable in the long run.
Increasingly businesses more removed from agriculture are pursuing soil carbon sequestration projects. Centurion Pipeline has begun a carbon capture project in west Texas teaming with Understanding Ag and EDGE Engineering & Science. EDGE has completed the baseline assessments of soils at two of Centurion’s sites, with plans to conduct progressive soil assessments in the future. During the first year of their project, Centurion has applied regenerative agricultural practices to roughly 25% of their 1,600 acres of unused land to sequester carbon from the atmosphere. Now we wait for nature to take its course. How quickly will we see a measurable difference? Oh, the suspense…
Soil carbon sequestration isn’t a climate change panacea: there’s no single solution to a problem this big. However, increasing carbon soil stocks is just as good for the earth as it is for the Earth.
EDGE Engineering & Science can help you navigate complex environmental and sustainability issues.
https://e360.yale.edu/features/soil_as_carbon_storehouse_new_weapon_in_climate_fight
https://news.stanford.edu/2021/03/24/one-earths-biggest-carbon-sinks-overestimated/
https://climate.nasa.gov/causes/