Finger Lakes Biochar

Exciting news!  Legislators in the NYS Assembly recently introduced the ‘Carbon Farming Act’ (A3281) which seeks to reward farmers for practices that maximize carbon sequestration in New York.  The bill acknowledges that ‘soil & vegetation management can significantly enhance soil & carbon sequestration’ while at the same time improving soil health, crop yield and water quality. 

To help educate the public on what this really means and build support for the bill, I am helping to host a one day workshop on May 20^th which will provide an overview of carbon farming methods, including a focus on biochar of course!  The workshop will review the proposed legislation and its potential impact on farmers and will include sessions led by students and faculty from Cornell University and Finger Lakes Biochar on carbon farming and biochar.  You will leave the event knowing how to make biochar, different kinds of equipment available to make it and a few ways to use it at home or on your farm.

I’ve rattled the cages of other biochar experts in the region and am happy to say that many of them will be on hand to provide demonstrations on how to make biochar and talk about using biochar in different ways.   Joining me will be folks from America Sequesters, Biomass Controls, Green Light Plants, Acorn Biochar, RIT’s Golisano Institute for Sustainability and more! 

Many thanks to our host, the Boathouse Beer Garden (6128 State Route 89, Romulus, NY 14541), a lovely spot off the West side of Cayuga Lake.  The good folks from the Ithaca chapter of the Citizens Climate Lobby have been helping to get the policy folks to the event as well. The event will kick off at 10am and run until 4pm on Saturday May 20^th.  Lunch and a local beverage (e.g. beer, wine or non-alcoholic) are included and a portion of the proceeds will be used to purchase organic produce from local farmers for the local Food Pantry.  Free biochar samples will be available to those interested in collaborating on small scale biochar trials.

If you’d like to join the fun, register now here or contact me if you would like to help sponsor or provide a demonstration at the event.

I suspect that many people don’t yet realize it, but acidic soils are a growing problem (so to speak!) around the world, already impacting more than 50% of soils used or suitable for agriculture.  Humans are both the cause and the casualty of soil acidification, though other biota are also impacted. We humans have come up with various solutions to combat low soil pH each with their own pros and cons some of which are outlined in a recent paper on this topic by Dai et all (see my summary infographic above).

In attempting to parse the biochar qualities that are relevant to increasing soil pH, the authors highlight feedstock and production temperature as being critical to designing or selecting the right biochar for this particular task.  They note that higher temps tend to increase fixed and total C, pH, ash, total exchangeable and soluable base cations and surface area.  At the same time however higher temps tend to lower yield, volatile matter, total O and CEC.  Generally speaking though if a ‘soil toiler’ wants to increase pH using biochar, so far the best advice points to using relatively high temperature chars (e.g. ~600C) from manure biomass or using a blend of biochars made from different feedstocks.

The discussion on mechanisms or how biochar reduces acidity, gets deep into the weeds of agronomy, but these are the general takeaways from my perspective:

• Soil acidity: alkaline biochars help acid soils but not alkaline soils – pretty logical!

• Certain biochars reduce Aluminum (Al) bioavailability & thereby its toxicity to plants; high surface area chars may provide more adsorption sites for Al and other metals

• Nutrient Availability – research is all over the map at this stage with one of the only consistent findings being that manure chars have more nutrients than chars from plant or woody feedstock.  This is widely acknowledged in the literature.

• Soil nitrification impacts – also seemingly inconclusive at this stage with much more research recommended.

Lots more work to be done on this subject, especially on long-term impacts of biochar and other soil amendments on soil pH, but overall it was a hopeful read!

Recently my ‘charmigo’ Ramon, who hails from Mexico, told me the only way he would support Mexico paying for a wall is if it was made from biochar.  The chuckle I could not suppress was filled with gallows humor. Still it got me thinking, not so much about walls, especially not between the US and Mexico which I believe is a complete waste of time and money as our US food system would quickly unravel if we did not receive the benefit of hard working Mexicans – but about other possible biochar based barricades.  Indulge my current biochar fantasy if you will please…

Although many would like to believe the biggest threat to civilization is citizens of one country trying to enter another in an effort to escape famine or fighting, the real threat to humanity and many other life forms is sea level rise. Below is a map of what a future USA could look like if the Arctic  ice keeps melting.

Forecasts from 6 – 12’ sea level rise are being projected with more and more certainty. Pretty dire any way you look at it.  Many threatened cities are talking about building sea walls to protect themselves.  But Mother Nature has a way of overcoming many manmade structures.  Which got me thinking about mountains – the ultimate land structure that stands up to rising tides.  Which got me further thinking about these kinds of man-made mountains, which I normally bemoan:

 What do all these capped landfills have in common?  On the upside (so to speak) they are tall, far higher than the worst case scenario of 12’ sea level rise. On the downside, they are pretty darn ugly and largely devoid of biodiversity. Oh, and most belch CH4 for up to 20 years after they are capped adding more fuel to the climate fire.  So creating a great wall of garbage mountains to fend off the rising seas is definitely not the answer. Besides most neighborhoods understandably detest them as they smell and decrease land values.

But what if instead of garbage under them there hills, we put lots and lots of carbon in the form of (mostly) biochar?  Create our own ‘Sea era Terra’ or Sierra Terra (a sierra is a chain of hills or mountains) as it were. Of course the entire ridge could not consist solely of biochar since that would not be structurally viable, but as our indigenous brethren in the Amazon and other cultures discovered, lots of other organic waste could be mixed in to add structural integrity and biological diversity to the mound. Blending charred and uncharred organics (and perhaps some non-toxic organic waste such as crumbled concrete), layer by layer, could build mountains of bounty where trees could be planted to further help pull down CO2 from the atmosphere.

As to the question of where to build, of course current beach homeowners would never allow a C-wall to be built to block their views (short term thinking!). Somehow we seem to have found a way to build pipelines over thousands of mills despite the fact that they destroy lands and landscape, so perhaps there is a way to find land for constructing climate cliffs. If successful such a wall has the potential to enrich a whole new corridor of real estate owners which might suddenly become coastal communities.  So the sales pitch to land owners would be more about potential land enhancement  rather than environmental hazards.

As to the question of with what, no need to fear that food growing land must be converted to biomass for biochar production.  On the contrary, as I have stated many times in this blog the world is nearly drowning in unloved biomass which could be carbonized.  Just recently a company told me they will soon be producing 20,000 tons of biochar per year from sewage sludge and tree debris in a small town not too far from me.  Converting tons to volume with biochar can be tricky and variable (due to density, particle size, etc.) but imagine 20,000 super sacks (which are already being used to reduce flooding elsewhere though not filled with biochar). Although super sacks come in all sorts of sizes, let’s take your average 2.5′ squared and tall sack for a bit of back of the envelope calculating.  There are 5,280 feet per mile, so 2,112 sacks would be needed per mile and a single layer would be 2.5′ tall.  That means this one small town could build a 2 mile long x 12′ tall carbon corridor from pyrolyzed sewage and tree waste in just one year.  That’s pretty astonishing when you think about it.

(Please note that I’m am not advocating for walls like this one, but rather mountains that promote biodiversity and beauty, but this gives an idea of how quickly and how far carbonized waste could go.) How to create such carbon filled precipices before humanity reaches that other looming precipice…that is the question that fueled my latest fantasy.

Next up on my reading list from the biochar bible, is Chapter 11 “Movement of Biochar in the Environment”.  Rather unsurprisingly something light and fluffy such as biochar is fairly mobile.  It can move both vertically down into the soil profile and horizontally across the landscape and into water bodies.  Lots of different forces cause this movement as can be seen from my one page overview above.

It is possible, in some scenarios, say for example freshly top-dressed, hydrophobic char applied on steep slopes with no soil cover, that quite a lot of char could be eroded away during the next big rain (similar to how freshly applied Nitrogen gets leached away). The final resting place of that biochar varies largely depending on topography, but there is a good chance that it could still sequester carbon whether it is in the soil or in a body of water. If char simply moves across land, it may fractionate and some tiny particles may volatilize, but much of the char will simply be moved from one spot to another – much to a farmers chagrin.  If it lands up in water, the carbon may still remain as carbon, but as with so many things related to biochar ‘it depends’! From what I can tell after reading this chapter, a lot more research is needed to really assess carbon stability in real-world vertical and lateral transportation scenarios of biochar.

If you want to reduce mobility, here are a few things to keep in mind:

• Particle Size –larger particle may fractionate into smaller ones when hit by raindrops; but smaller particles will tend to leach and erode more quickly;
• Hydrophobicity – fresh char, especially made at low temps (<500) is likely to move more
• Soil texture matters as always! Sandy soils will experience more leaching & erosion.

What they didn’t say: A lot of chatter about biochar tends to tout ‘once & done’ benefits of biochar but in fact according to this chapter biochar can be quite mobile so ‘once & done’ could end up as ‘once & gone’ under the right (or really wrong) circumstances.  Ancient soils such as Terra Preta in the Amazon or the Plagganthrepts soils in Europe (see picture in lower left hand corner above) are not the result of single applications.  These soils were continually amended with char and other organic wastes for decades or centuries and created a deep dark soil profile that has persisted for millennia.  It is highly unlikely that adding a single instance of biochar, even at high application rates, would create similar profiles.  Thus adding lower rates more frequently may be preferable in the long run for both long-term carbon storage and soil fertility.

Sand. How in the world can we be running out of sand? The world seems full of it, right? River-beds, oceans and deserts are full of sand.  Yet according to a number of recent articles, certain types of sand are being depleted so rapidly that some countries are putting bans on exporting it.  Such bans have given rise to sand mafias in some parts of the world.  Such sand mafias, which could have been called  Sandinistas if the name hadn’t already been taken, clandestinely mine river-beds and vacuum ocean floors to sell this finite resource to voracious buyers both far and near, leaving behind devastated eco-systems and sandless beaches.

To what end you ask? Our insatiable appetite for concrete is largely to blame; more specifically for the construction of housing, offices, factories, in fact brand new cities that spring up practically overnight in some parts of the world.  One kilometer of road requires 30,000 tons of sand and a single house can quickly use up to 200 tons (more details here). Concrete accounts for 80% of mined sand usage. Depending on the specific end use for concrete, up to 3 times the amount of sand will be required for every part of cement. Its role is to fill in the spaces of larger aggregates (e.g. stone). Both fine and course sand are used in cement with varying impacts on comprehensive strength, flex strength, permeability, durability, shrinkage, cracking, etc. Desert sand, due to its smoother and rounder geometry, doesn’t work as well as river and ocean sand so it is largely ignored.

Given that I blog about all things biochar, where does biochar come in to play on this most recent tragedy of the commons (i.e. disappearing sand)?  It is no secret that biochar is being tested and used in concrete recipes (see here, here, and here).  To date, however, the motivation for including biochar in concrete has focused on carbon sequestration or to lighten up the weight of concrete.  Perhaps displacing the use of sand with biochar in concrete should focus more on the ecological benefit of saving our rivers, oceans and related flora & fauna from utter devastation.

But since eco-system services is often a tough sell, especially without regulations to control those that feel no shame in ruining the environment, economic impact must be addressed.  Sand is still shockingly cheap (roughly $6/ton) given that it is the most in demand natural resource after water.  At that rate, biochar is unlikely to compete purely on price for a very long time.  However this recent paper suggests the biochar added to cement can help reduce cracking and improve flexural strength as compared to using just sand for the fine aggregate. This same research claims that biochars ‘jagged and irregular shape provides a snug fit to cement paste’.  Earlier research out of Korea showed that certain types of biochar ‘reduces water evaporation from concrete which reduces both the plastic shrinkage and drying shrinkage’.  Thus improving concrete through the use of biochar could potentially reduce liabilities related to concrete failure, or reduce curing time which means faster building, or could provide better insulation which will reduce building operating costs.  If we start to approach the use of biochar in buildings through this lens, it just might attract more interest than focusing on its carbon sequestration potential.  Future research would be well served to use a Triple Bottom Line approach to using biochar in building materials.