Biochar—a soil restorative–useful in agriculture and forestry
Elmer “Dusty” Moller, Wood Utilization Manager, Business Environmental Program, University of Nevada Reno
Introduction
In the summer of 2012 in Ely, Nevada, a handful of dedicated researchers processed some Pinyon Pine and Juniper in a way that hadn’t been done for more than 100 years. They turned it into charcoal! Or rather, agricultural grade charcoal because they intend to bury it rather than burn it. The researchers, members of Nevada’s Pinyon Juniper Partnership (PJP), used a pyrolizer that converts biomass–biological material from living, or recently living organisms, most often referring to plants or plant-derived materials—into a charcoal-like substance called biochar.
Pyrolizers produce char, liquids and gases by heating the biomass at high temperatures with little or no oxygen present. In the Ely project, however, only the char was collected. What was in store for that char involved some of the top soil scientists, rangeland specialists, and mine reclamation experts in the United States.
Biochar—how it’s made and how it works
In the late 1800s, charcoal used for smelting ore mined in NE Nevada was manufactured in “beehive” kilns, like those located in Ward, Nevada (Figure 1). Each kiln would hold about 35 cords of wood and take 10 days to produce 1,750 bushels of charcoal. In 2012, the pyrolizer (Figure 2) used about 6 tons of whole tree chips and produced about a ton of a form of charcoal known as biochar. The chemistry is similar, but the end use different. The early charcoal was produced for its heating properties; today’s biochar is manufactured as a soil amendment.
In its role as a soil amendment, biochar acts like a sponge; indeed, when seen through an electron microscope, it looks like sponge or block of Swiss cheese.
It is the tremendous surface area and pore structure that makes biochar “work”. All the nooks and crannies offer secure housing for fungi and micro-organisms. Therein lies the “secret” of biochar. Char act as a host to mycorrhizal fungi, an association wherein the mycorrhiza colonizes the plant roots.
…”Mycorrhizas form a mutualistic relationship with the roots…This mutualistic association provides the fungus with relatively constant and direct access to carbohydrates, such as glucose and sucrose. The carbohydrates are translocated from their source (usually leaves) to root tissue and on to the plant’s fungal partners. In return, the plant gains the benefits of the mycelium’s higher absorptive capacity for water and mineral nutrients due to the comparatively large surface area of mycelium: root ratio, thus improving the plant’s mineral absorption capabilities.” (Harrison, MJ.
2005)
More simply put, the highly absorbent char may take in water, fungi and nutrients and help plants grow better.
Biochar’s Role in the “Carbon Revolution”
The Ely char was produced from mostly Utah Juniper trees removed from a Bureau of Land Management (BLM) fuels reduction treatment in White Pine County, Nevada. A chemical analysis was performed on the char. According to an International Biochar Initiative (IBI)-based method, the char was nearly 70% organic carbon and with a heat value of more than 11,100 Btu/lb. While that fuel value is impressive, the Ely researchers were bent on showing that the higher end use for the char is as a soil amendment. In that application biochar may improve water use efficiency, decrease soil acidity, reduce fertilizer requirements, improve plant growth, and more.
The first step in the project was to demonstrate that the char “would do no harm”. USDA-ARS soil scientist, Dr. Jim Ippolito, at the Northwest Irrigation and Soil Research Station in Kimberly, Idaho, conducted a four month “pot incubation study” using four types of Northeast Nevada soil and two types of char—one made solely from Utah Juniper; the other, Pinyon Pine. (Earlier char studies have shown significantly different results that depended on what the char was made from and the combination of time and temperature used in the production process.)
No nutrients were added as the alfalfa seeds being studied began to sprout. Ippolito’s preliminary findings indicated that char was a “neutral” factor in terms of nutrient addition, but was a “positive” factor in terms of increasing plant-available water and a subsequent increase in alfalfa germination rate. After that study, the Ely group could show land managers, mine operators and gardeners that biochar was not detrimental; so the next step was to demonstrate just how much it was going to help.
The changing culture of American agriculture
Understanding how American agriculture got to where it needs help by adopting new methods of revitalizing soil is important. Perhaps the first “marker” is the Dust Bowl era and the devastation that plagued the US in the early 1930s. Two culprits are most frequently mentioned as prime contributors to the failure of agriculture throughout the US mid-west—drought and deep plowing–the ground preparation most favored at the time. Lack of water and deep plowing followed the move to increase cultivation in the mid-west. Farmers were reacting to the increase in food prices generated by the demands of World War I.
Among the Dust Bowl impacts of loss of farm production—in many cases, loss of the land, literally, as tons of top soil were stripped from the farms, was the inability of farmers/ranchers to feed their herds. The Federal government responded with a series of programs under the direction first by the Soil Erosion Service in 1933; then, the Soil Conservation Service which became today’s Natural Resources Conservation Services. Farmers were given money to use “conservation” farming methods—crop rotation, strip farming, contour plowing, among others. The government aided the ranchers by buying up the herds of animals—then, slaughtering the animals unfit for food and processing the remainder to feed citizens through a variety of distribution programs. When the drought passed, a strong relationship between the Federal government and US farmers and ranchers had been forged and continues today.
The second “marker” occured in the 1970’s when Department of Agriculture switched from a policy of restricting production to maintain stability in US agriculture production to a policy of “plant fence row to fence row”—a program dependent on expanding exports and price supports when international markets didn’t provide the necessary demand for the rapidly increasing US supplies.
The culture of American farming appears to have adopted the model of “profit maximization”—extracting the most and best crops from as many acres as possible while holding costs to minimum levels. This maximization, however, may not always prove best for the land and other natural and common pool resources.
For example, some studies show that, worldwide, about 70% of freshwater stocks are used to grow food. While a somewhat lower percentage is reported for the US, the source water and location of the farmed land is critical. For example, the Ogallala Aquifer occupies more than 170,000 square miles in an area bounded by Wyoming and South Dakota in the north and New Mexico and Texas in the South. Enter two problems: overpumping and climate change. A New York Times article explains the former problem:
“Sixty years of intensive farming using huge center-pivot irrigators has emptied parts of the High Plains Aquifer. It would take hundreds to thousands of years of rainfall to replace the groundwater in the depleted aquifer. In 1950 irrigated cropland covered 250,000 acres. (Then) with the use of center-pivot irrigation, nearly three million acres of land were irrigated. In some places in the Texas Panhandle, the water table has been drained (dewatered). Vast stretches of Texas farmland lying over the aquifer no longer support irrigation. In west-central Kansas, up to a fifth of the irrigated farmland along a 100-mile swath of the aquifer has already gone dry.”
It’s climate change that has some observers really concerned. The map (below) shows the long term impacts of drought throughout the US:
Figure 4: Long Term Drought Indicators
While the Ogallala Aquifer is not recharging at a rate to replace water extraction, the amount of precipitation the area receives is decreasing. And, from the drought map, the message for Nevada is clear—expect less rainfall (Nevada only averages 7 inches of rain annually now!) and be extremely cautious with ground water removal. Perhaps the findings of the Ippolito study—the possibility of increased water efficiency and improved germination—will come into play. First, however, considerable amounts of biochar need to be produced to test out biochar’s value to Nevadans.
Biochar—a growth industry with critical requirements
Creating a brand new industry in Nevada is a tall order. Nevada has a rich history in converting large tracts of Pinyon/Juniper to charcoal—used throughout the state as a fuel and process element for smelting mine ore. But, biochar is different than charcoal. In order for biochar to succeed in the markets of rangeland, farm land, mine spoils and urban settings, biochar has to satisfy these four conditions:
Figure 5: Homestyle Biochar Production Unit
Inventive technology—Entrepreneurs must find ways to efficiently convert biomass to biochar in a wide range of production settings. In urban settings, a TLUD “kiln”, shown in Figure 5, can convert urban tree waste to char. The name TLUD comes from the burning process involved. The compartments inside the barrel contain fuel wood and biomass. The fuel wood is ignited at the top layer (TL) and the fire is stocked from the bottom using an up draft (UD). The downside to this technology is the smoke—similar to a barbecue’s output, but lasting all day! City burn ordinances and complaining neighbors will limit the acceptance of this production method.
Biomass has a relatively low value and can’t be profitably transported very far. Char, while having a higher value, works best when blended with nutrients or composted and that step is most efficiently accomplished close to the application site—again reducing transportation costs.
In a recent study conducted by Humboldt State University researcher, Han Sup Han, the cost to move biomass-whole trees felled (sawn down) to the ground-from where they landed to a processing facility was nearly $50/BDT. (BDT equals “bone dry ton”-an estimate of the fiber present after the moisture has been removed.) Some biochar conversion processes can achieve a 25% recovery-using 4 tons of biomass to yield 1 ton of biochar. Thus, the cost of the raw material would be approximately $200 per ton.
Figure 6: PJ Biomass Utilization Costs
Adoptive markets—Eager, early adopters need to be present within each of the markets to help “pull” the char through the production process. Those market leaders need to be reminded of the role that carbon plays in the soil. Stable forms of soil carbon, like biochar, can increase farm profitability, urban tree survival and home garden success by increasing yields, soil fertility, soil moisture retention, aeration, nitrogen fixation, mineral availability, and disease suppression. Carbon is a major contributor to healthy soil! Like one dedicated collaborator in Eureka, Nevada, said, “We’re running out of options to improve our soils and this one shows promise”.
Stealth business plan—Operators need to complete a thorough investigation of resource availability, production and application costs that, when balanced against improved crop yields, leads to the conclusion that biochar use “will pencil out”. An extremely strong “Customer Value Proposition (CVP)” must be developed that will help investors overcome the fear of the many unknowns that accompany using a “new” product or starting a new industry. At the heart of the CVP are the mechanisms that drive the profit formula—ingredients (seed, biochar, water, fertilizer, labor) in; quality and quantity of production out.
Favorable government policy–With more than 9 million acres of the PJ forest type, the Ely district of the BLM is a key player in the Nevada biomass market. The district has a budget for healthy forest restoration. Restoration activities are summarized in “task orders” where specific tasks are prescribed. Those prescriptions are deemed fulfilled or complete when a function is accomplished. For example, if the activity is to “masticate” the PJ–grind in place—then the appropriate machine does precisely that. In another case, “lop and scatter” means to feel the PJ and then cut off and scatter the limbs over the surrounding ground.
At the point in time when the sawyer has dropped the tree, it can be “utilized”. Up to this point, it has typically cost the BLM about $250 an acre for the labor and machine work. If the fiber is to be utilized, it could cost BLM another $250—assuming 5 tons of PJ per acre–to see the fiber delivered to a nearby processing plant. In this example, then, prescribing “utilization” doubles the cost of treatment! The biomass developed has value but without the budget to remove the biomass from the forest on the front end and the investment in research to efficiently process the biomass into biochar on the backend, making the carbon farm or garden ready is not going to happen.
Through regulatory action, research, grant funding—the whole gamut of tools that the US Department’s of Agriculture and Interior use to get things done—corrections, changes, adjustments, even policy reversals, need to occur. One instance, the tactic of “pile and burn” used on forest slash after hazardous fuels reduction or forest health projects has many weaknesses. Biochar created from that biomass can be returned to the forest floor or used in nearby markets. In another case, urban biomass currently landfilled, can be converted to biochar for use in gardens, urban canopy cover restoration, lawns, gardens, golf courses—the list is endless.
Nevada’s Biochar Markets
Broad Acre Agriculture—With Nevada being the driest of the 50 US states, biochar’s water efficiency is an attractive product characteristic. What would an extra inch of rain mean to NE Nevada’s alfalfa farmers? Research from Iowa State University offers a tantalizing answer:
While no meteorologist or agronomist can accurately predict which years will be “dry years,” scientists and farmers can now take steps to protect themselves against plant dehydration during a drought…Biochar exhibits many unique properties that could provide aid to combat future dry spells, the most noteworthy being water retention. In a lab study conducted at Iowa State, researchers discovered biochar increased the soil’s water retention by 15 percent.
“This year, [water retention is] huge because of the drought,” said David Laird, professor of agronomy. “If you can improve the soil quality and make it so the soil holds water better, then it will be more robust in a dry year.” (Debner, 2013)
Since it would be cost prohibitive to try to apply biochar on a large Nevada ranch, could it be selectively applied just to the area where the plant could benefit the most from it?
One New Zealand researcher, Don Graves, Motueka, Aotearoa New Zealand uses a unique seed drill/ disc to do just that. The soil profile shown in Figure 7 illustrates the location of biochar slurry occupying both horizontal seedbed shelves and the vertical column produced by the disc designed to cut through crop residues. (Graves, 2012a, unpublished).
Figure 7: Biochar Slurry Applied w/Cross Slot Device
Forest/Rangeland Restoration—An important part of marketing is delivering the product. Biochar production processes can yield a considerable amount of dust-like fines or ash. When Dr. Debbie Page-Dumroese, a researcher with the US Forest Service Rocky Mountain Research Station in Moscow, Idaho, conducted a trial on the Umpqua National Forest, her delivery method called for the use of 5 gallon buckets! Figure 8 shows that application technique. (Page-Dumroese, 2011). A delivery technique that served for a scientific study could find reluctant clients for larger field trials.
Figure 8: Biochar Manually Applied in Forest Study
Mine Reclamation–Char can be pelletized and, plain wood pellets can be charred. New Zealander Don Graves manufactured clay-coated biochar pellets by charring standard wood stove pellets then coated them with a clay/fertilizer coating. This version of biochar could prove useful in mine reclamation applications where top application might be the best way to introduce biochar to mine spoils.
Figure 9: Standard wood pellets – charred and coated
Urban Forests—an important and fast growing market are our urban forests. Canopy cover within our cities is an important controlling factor for pollution and flood control. But the environment offered by concrete and pavement is extreme. This worker is drilling into the planter box in order to apply char to the root zone of this established tree. The char, along with a dose of nutrients will go a long way to increase tree growth and survivability.
Figure 10: Urban Forest Biochar Application
Gardeners–The USDA-ARS pot studies mentioned previously were based on application rates determined for 0, 1, 2, and 5% by weight; those equivalent to 0, 10, 20 and 50 tons per acre. Ippolito concluded that “soil moisture content tended to be at its greatest with the 1% biochar application rate. A correlation analysis was also performed between average alfalfa germination means for the entire study period versus average soil moisture content for the entire study period. A significant relationship was found suggesting that increases in soil moisture due to increasing biochar application may be tied directly to increases in alfalfa germination success.”
Urban gardeners can easily make use of this research. The first step is to measure the garden and determine the square footage. At a recommended 1% application rate, a square foot of garden soil, at a tillage depth of 6 inches or so, would require about 1/2 pound of char. Depending on the density of the char, that would convert to about 3 cups/per square foot. When applying the char, adding some inorganic nitrogen fertilizer can offset the initial absorptive activity of the char. As stated, once the mycorrhizal community is established, overall fertilizer needs may diminish.
Figure 11: Currently Marketed Biochar Products
Biochar—a dark product with a bright future
Natural and native-made chars go back in time several thousand years but the groundswell of re-introducing char as a soil amendment is a recent phenomenon. And it is a grassroots phenomenon at that. The industry, as least in the US, is characterized by a few industrial producers scattered across the country but there are scores of small producers—many operating TLUD kilns in backyard “factories”.
Much is unknown about the behavioral characteristics of Pinyon/Juniper-based chars as applied to the Nevada market venues. Yet the upside of the benefits of using char is tremendous. Take the water efficiency aspect alone. Users of similar chars in agricultural applications report water efficiency improvement of 15% or greater. Others report crop yield increases greater than 50%! In specialty applications, like mine reclamation, operators report successful reclamation where previous attempts, not using char, failed.
Nevada’s carbon history is connected to Nevada’s carbon future
The operators of the 19th century industrial charcoal kilns in Northeast Nevada were called “carbonari”—recruits from Spain and skilled in the art of making charcoal. Modern day Nevada “biocharists” have a different bent. Their goals range from sequestering carbon as a preventive measure for climate change to gaining the water and growing efficiencies shown in laboratory studies and initial field trials. Using the Nevada’s renewable Pinyon/Juniper resource for today’s aims just might give Nevadan’s a chance to rewrite the state’s Pinyon/Juniper forest history.
For more information:
The International Biochar Initiative has published IBI Biochar Standards in their role as the lead scientific agency involved with the establishment of the biochar industry. The Standards plus the most complete database of published biochar research and current research projects are available at http://www.biochar-international.org/
The US Biochar Initiative consists of more than a dozen chapters throughout the US—each dedicated to using local biomass resources to produce chars for local markets: http://www.biochar-us.org/regional%20chapters.html
The 2013 North American Biochar Symposium will be held October 13 through 16. Symposium agenda, registration and subsequent proceedings will found here: http://symposium2013.pvbiochar.org/
The Pinyon/Juniper Partnership is conducting some of the research describe herein. Their goal is to minimize ecological risks while engaging in landscape level Pinyon/Juniper forest restoration, with utilization of the resulting biomass as an additional beneficial outcome: http://www.nvpjpartnership.org/
Works Cited
The results of the cited Ely biochar “pot study” are contained in a report authored by Jim Ippolito, USDA-ARS-Northwest Irrigation and Soils Research Laboratory, entitled “Pinyon Pine and Juniper Biochar Application to Four Eastern Nevada Soils”. An electronic version of that report is available by contacting Dusty Moller, Wood Utilization Manager, University of Nevada Reno at dmoller@unr.edu
Harrison MJ. Signaling in the arbuscular mycorrhizal symbiosis. Annu Rev Microbiol. 2005;59:19-42.
Debner, E. Biochar is an investment in soil. Accessed 7 May 2013. Available from http://www.iowastatedaily.com/news/article_1e80d8e8-01a1-11e2-8ada-001a4bcf887a.html
Graves, D. Personal Communication
Page-Dumroese, D. Environmental Consequences of Biomass-to-Biochar Technologies. Quoted in: http://forest.moscowfsl.wsu.edu/smp/solo/documents/GTs/McElligott-Kristin_Thesis.pdf
Wilson, K. Various “Blog” articles at: www.kelpiewilson.com/biochar
Additional information and guidance on the most current biochar research can be located by contacting the following “LinkedIn” groups: http://www.linkedin.com/
- International Biochar and BioCarbon Group
- Biochar Commercialization
- Biochar Farms and Gardens
- Biochar Offsets
- Biochar Soil and Fertilization
- Northwest Biochar Market Group