How Biochar Can Help Depleted Soils

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October 12, 2013 | 234,534 views

Story at-a-glance

  • Biochar is created by slowly heating biomass (wood and other plant materials) in a low-oxygen environment, such as a kiln, until everything but the carbon is burned off and then putting it into the ground
  • Biochar can help reverse rising CO2 levels in the atmosphere; improve overall soil quality, and raise soil’s water retention ability. It may also help “filter” toxic chemicals in the soil
  • Adding biochar to just 10 percent of the world’s croplands would store 29 billion tons of carbon dioxide equivalent. This roughly equals the world’s annual greenhouse emissions
  • More importantly, addition of biochar would radically improve the soil fertility and allow the production of far healthier crops
  • US soils alone could absorb up to 330 million tons of carbon annually with better carbon management practices. That’s enough to offset all car emissions in the US, while simultaneously boosting food production by 12 percent

By Dr. Mercola

Lately, I've become impassioned with high-performance agriculture as an alternative to more harmful agricultural practices such as genetic engineering and chemical-dependent conventional farming.

High-performance agriculture also presents us with an excellent route to renewing and restoring our environment as a whole, as well as combating desertification, or the turning of lands into desert. I am particularly excited about the use of biochar as a tool to improve soil health.

What Is Biochar?

Producing biochar involves slowly heating biomass (wood and other plant materials) in a low-oxygen environment, such as a kiln. This type of charcoal can do a number of things:

  1. Help return much of the depleted carbon to the soil
  2. Improve overall soil quality
  3. Raise soil's water retention ability
  4. It may also help "filter" toxic chemicals in the soil, much like carbon-based water filtration systems can filter toxins out of your water

When put back into the soil, biochar can stabilize the carbon in the soil, in the form of charcoal, for hundreds or even thousands of years.  It serves as a type of 'coral reef' of the land, where it's porous and massive surface area provides a great benefit to soil microorganisms

The introduction of biochar into soil is not like applying fertilizer; it is the beginning of a process. Most of the benefit is achieved through microbes and fungi. They colonize its massive surface area and integrate into the char and the surrounding soil, dramatically increasing the soil's ability to nurture plant growth.

Helping Nature to Self-Correct Is Within Our Power

Modern day agriculture has removed much of the native grasses, which were very deep rooted and quite resilient, able to survive even the most challenging droughts.

When fields were plowed up to create the soy, corn and cotton mono-cultures that exist today, we lost much of the carbon in the soils while we also increased the amount of carbon in the atmosphere.

As discussed in the featured article, the extraction of carbon dioxide from the atmosphere is necessary if we want to get a handle on the ever-rising Co2 levels in our atmosphere. By focusing on reducing annual emissions, we may indeed be missing the boat.

According to Albert Bates,1 author of The Biochar Solution, if all carbon emissions were stopped today, it would take a minimum of 50 years to see the effects, and it would take 6,000 years for the world's oceans to absorb all the man-made carbon from the atmosphere.

One of the most promising means for extracting atmospheric carbon is by taking advantage of the natural process of photosynthesis.

According to Johannes Lehmann, a professor of agricultural science at Cornell and an internationally recognized expert on biochar, adding biochar to just 10 percent of the world's croplands would store 29 billion tons of carbon dioxide equivalent. This roughly equals the world's annual greenhouse emissions.

Bates claims there should be plenty of leeway to "bury" significant amounts of carbon, as many of the world's fertile soils used to have a carbon content of as much as 20 percent, whereas today, they typically average somewhere between 0.5 and five percent. The more depleted a soil is, the more carbon it can accept back, which is good news for many areas.

According to Rattan Lal, a soil scientist at Ohio State University, US soils alone could absorb up to 330 million tons of carbon annually with better carbon management practices. That's enough to offset all car emissions in the US, while simultaneously boosting food production by 12 percent, courtesy of carbon's beneficial effect on soil quality.

He estimates that if man-made emissions were brought to zero, carbon farming could cut atmospheric carbon by one part per million (ppm) every four years (remember we're currently raising it by 2 ppm per year).

"This approach would take advantage of a physical reality often overlooked in climate policy discussions: the capacity of the Earth's plants and soils to serve as a climate 'sink,' absorbing carbon that otherwise would be released into the atmosphere..." the featured article states.

Biochar Catalyzes Soil Regeneration—A Win-Win for our Environment

As explained by Dr. David Shearer, CEO of Full Circle Biochar, in the featured article, fire has historically been the driving force of the Earth's carbon cycle. Natural fires started by lightning would burn large swaths of plants and trees, returning the carbon they'd absorbed to the soil in the form of charcoal.

Today, most societies take steps to prevent wild fires, and greatly restrict the practice of burning fields and woods. Rather than burning open land, biochar would be created by burning tree trimmings, crop stalks, manure and other biological "leftovers" that currently end up decaying in landfills, where their slow decay adds to the greenhouse effect.

According to Dr. Shearer: "Producing biochar is a way to begin restoring the proper balance by catalyzing soil regeneration through the addition of biochar to soils."

Lehman's research shows that adding biochar to soil also increases the fertility of the soil, as well as its ability to retain water, which of course is a significant benefit. Adding biochar might therefore make agricultural land more resilient against environmental factors like drought, which is predicted to get worse in the years ahead. (Biochar's ability to retain water is due to its porosity, as explained in Bates' book, The Biochar Solution. Just one gram of biochar, about the size of a pencil eraser, has a surface area of 1,000-2,500 square meters.)

According to the featured article:

"Other proven methods include growing trees—both in forests and mixed among field crops—and changing to less invasive tillage systems. Instead of industrial agriculture's practice of removing crop residues and plowing soil before planting, which releases large amounts of carbon into the atmosphere, 'no-till' cropping leaves residues in place and inserts seeds into the ground with a small drill, leaving the earth basically undisturbed.

A calculation by the Rodale Institute, a non-profit agricultural operation in Pennsylvania, found that if 'no-till' methods were used on all 3.5 billion acres of the Earth's tillable land, it would sequester more than half of humanity's annual greenhouse gas emissions. 'If ideas such as biochar emerged recently,' Lehmann asks, 'what other ideas might still be out there?'

Earlier in this monthlong Slate series... Michael Pollan and I discussed how taking advantage of photosynthesis could turn eating meat from a climate sin into a blessing by relying on the same ecological principles that make biochar possible. The key is not meat versus no meat. The key is to reform agricultural systems away from the current industrial approach that uses vast amounts of petroleum to produce food in favor of systems that rely on natural processes such as photosynthesis. Pollan calls it the 'oil food' versus 'sun food' choice."

'Oil Food' versus 'Sun Food'

The idea that eating meat is bad for the environment has been presented from time to time. Not only do confined animal feeding operations (CAFOs) pollute soils and waterways, they also play a role in rising Co2 levels. Conventional large-scale industrial farming of both crops and animals is profoundly petroleum-heavy, from start to finish, and is a significant contributor of greenhouse gas emissions. According to a previous Slate magazine article:2

"[T]he industrial agriculture system employs 55 calories of fossil fuel energy to produce 1 calorie of beef. Meanwhile, livestock production is responsible for much of the carbon footprint of global agriculture, which accounts for at least 25 percent of humanity's annual greenhouse gas emissions, according to the U.N. Food and Agriculture Organization."

Meanwhile, reverting back to a system of pastured animals may be another part of the solution to rising carbon levels. A few months ago, I posted a TED Talk by ecologist Allan Savory, in which he explains how we're currently encouraging desertification (i.e. turning land into desert), and we can not only stop it, but reverse it, by dramatically increasing the number of grazing livestock on the planet. By some estimates, grazing large herds of livestock on half of the world's barren or semi-barren grasslands could take enough carbon from the atmosphere to bring us back to preindustrial levels.

Michael Pollan has similar ideas, and he too believes that changing our agricultural systems may be the answer to a number of our current problems. In fact, many of his ideas mirror Savory's holistic management of grasslands using grazing herds. According to Slate:

"The upshot, both for global climate policy and individual dietary choices, is that meat eating carries a big carbon footprint only when the meat comes from industrial agriculture. 'If you're eating grassland meat,' Pollan says, 'your carbon footprint is light and possibly even negative.'"

So how do grass-fed cattle help sequester carbon, you might ask? Again, it starts with photosynthesis. Plants absorb water from the soil and carbon dioxide from the air, and convert energy from the sun into chemical energy used to fuel the plant's growth activities. Pollan explains how the carbon captured in the plants' leaves and roots is then sequestered in the soil by grazing cattle:

"When you have a grassland, the plants living there convert the sun's energy into leaf and root in roughly equal amounts. When the ruminant [e.g., a cow] comes along and grazes that grassland, it trims the height of the grass from, say, 3 feet tall to 3 inches tall. The plant responds to this change by seeking a new equilibrium: it kills off an amount of root mass equal to the amount of leaf and stem lost to grazing. The [discarded] root mass is then set upon by the nematodes, earthworms and other underground organisms, and they turn the carbon in the roots into soil. This is how all of the soil on earth has been created: from the bottom up, not the top down."

This process also improves water retention in the soil, thereby raising crop yields on grazed land while reducing water usage. As stated earlier, it also raises the crop's resilience to drought and floods. Says Pollan:3

"'I'm a believer in geoengineering of a very specific kind: when it is based on bio-mimicry'" — that is, it imitates nature — 'rather than high-tech interventions and when instead of being a silver bullet solution it solves multiple problems--in this case... soil quality and food security.'"

Two Farming Methods—Two Very Different Environmental Impacts

On numerous occasions, I've stated that the differences between industrial farming and organic farming, using time-tested all-natural methods, are so vast that the foods produced by the former cannot be equated to the foods produced by the latter. The environmental effects are also 180 degrees opposed, as industrial farming contributes to every form of environmental devastation, while organic farming methods restore the environment and invigorate and support the ecosystem—of which humans are an integral part, I might add.

Many equate modern techniques with "progress," when in fact most of our technological advancements are now threatening to destroy us right along with the planet as a whole. As Pollan suggests, I agree we need to reevaluate what technology really means.

"Does it only mean hardware and intellectual property? If we limit it to those two definitions, we're going to leave out a lot of the most interesting technologies out there, such as methods for managing the soil and growing food that vastly increase [agricultural] productivity and sequester carbon but don't offer something you can put into a box," he says.4

Should We Label Factory-Farmed Food?

Some organic proponents are now proposing yet another label, aside from labeling genetically engineered foods, and that is to label foods produced by CAFO's. A new alliance of organic and natural health consumers, animal welfare advocates, anti-GMO and climate-change activists has been created for this purpose. This Truth-in-Labeling campaign5 will begin with a program to educate consumers about the negative impacts of factory farming, and then move forward to organize and mobilize millions of consumers to demand labels on CAFO-produced animal products.

"Opponents and skeptics will ask, 'What about feeding the world?' Contrary to popular arguments, factory farming is not a cheap, efficient solution to world hunger... Feeding huge numbers of confined animals actually uses more food, in the form of grains that could feed humans, than it produces. For every 100 food calories of edible crops fed to livestock, we get back just 30 calories in the form of meat and dairy. That's a 70-percent loss. With the earth's population predicted to reach nine billion by mid-century, the planet can no longer afford this reckless, unhealthy and environmentally disastrous farming system.

We believe that once people know the whole truth about CAFOs they will want to make healthier, more sustainable food choices. And to do that, we'll have to fight for the consumer's right to know not only what is in our food, but where our food comes from."

There's no denying that declining food quality and destruction of agrarian soils and rapid conversion of fertile land to deserts is a serious threat to us all. And technology in the form of ever larger-scale, industrial farming methods using more chemicals simply isn't the answer. It's making it WORSE... I believe Savory, Pollan and others are correct when they say our only hope is to revert back to what worked before. For now, you can help move our agricultural system in the right direction by purchasing your food from local farmers who are already doing this on a small scale.

[+]Sources and References [-]Sources and References

  • 1 The Biochar Solution by Albert Bates
  • 2 Slate July 2, 2013
  • 3 See ref 2
  • 4 See ref 2
  • 5 CAFO