Growing corn to sequester carbon?

Invitiation for some Green Hat thinking--(creative thinking)--


What changes if you change the goal?


I'll take a shot at some creative thinking here.  (Note I'm going to use Edward de Bono's thinking tool here.  The nonsense word "PO" indicates that the the thing it modifies is new and different from what has been in the past.  For example "PO flying machine allows human beings to fly like birds" lets the Wright Brothers think of an airplane even before the thing or even the concept existed.  It's a thinking prompt.)

PO corn isn't edible.  It is not bred for human palatability, corn syrup, or even cattle feed, so you can make it as tough or tasteless as it needs to be and favor hardiness and size.

It can grow wherever you have a free spot, it doesn't have to allow a harvester to run over it, or even be reachable by humans.

It could coexist with wind farms (windmills) on farms.

It could be kernels thrown on top of green roofs of industrial buildings or offices.

It could make for carbon offsets in places where you can see them (vs I paid someone to say that they planted a tree on the other side of the world, but I don't actually know through direct sensory observation).  Corn is more portable and needs less space.

(Btw it's a time-sensitive thing to get our air back in balance--we could use temporary boost)

Location relative to consumers, sellers or cattle not needed. It could be grown in a desert if it somehow could get the water and dirt it needed.  It could grow on a big raft anchored out at sea.

PO corn need not make money.

PO corn isn't corn.  Naybe other plants that use the C4 photosynthesis process instead of C3 (sorghum eg, wild plants?) (Corn captures more carbon than other plants because it drinks in 4 carbon atoms through its stomata with each "sip" of air it takes. )

Po corn decreases corn growth.  A program paying farmers to capture carbon, rather than paying them to grow corn for the market (I know, the corn subsidies aren't real, but the petroleum products subsidies sure are, for the nitrogen fertilizers).  Or instead of paying farmers not to grow anything at all. Or instead of ethanol.

PO corn wears glasses.  Mirrors or lenses focusing sunlight on the corn ??

Ps--robots could grow these in the desert without the need for water and food for human farmers.  They could harvest their own ethanol for fuel...or just charge off solar panels.  The robots needn't do a great job, just good enough to keep corn alive.  

And maybe shuck some ears to plant the next crop of corn.

Corn doesn't grow all that well in the desert.  There are other grasses which are better adapted.

For semi-arid areas I like prairie grasses such as Switchgrass.  Also these don't need to be planted each year, being perennials.

I can grow Switchgrass without irrigation or protection from deer.  I can't grow corn that way.

Remember that "sequestration" in a carbon crop is only as good as the means of storage. If you're just putting it back into the soil, most of the carbon will be back in the atmosphere in a couple of years. This is not a bad thing in itself, as carbon is vital to soil health and it's all part of the biological cycle. But it's a flow and not a stock. You have to add a similar amount every year to keep soil C levels up, and the amount that is converted to humus is comparatively tiny.

If you're looking at removal of carbon from the cycle, you will need to pyrolyse that corn. Or hemp, switchgrass, miscanthus, or whatever you grew.

I wish there was a corn subsidy this year as I would have actually gotten it, and the ethanol subsidy was phased out several years ago.

I do not think corn is the evil crop that most people believe it to be though, and was a staple of the pioneers that came to Maine for a lot of good reasons. Those poor saps ate the stuff 3 meals a day, but back then, it really made sense due to how it grows, and where they were planting.

Phil Stevens wrote:

If you're looking at removal of carbon from the cycle, you will need to pyrolyse that corn. Or hemp, switchgrass, miscanthus, or whatever you grew.

If you're pyrolyzing anyway, you can make the crop pull double duty and pyrolyze the crop waste from food or fiber crops. Stalks, vines, and empty pods from legume crops. Cobs and husks from the corn. Stalks and shells from sunflowers. Vines and leaves from squash or melons. Chaff from linen or hemp. Hulls and shells from nut crops. Above-ground parts from potatoes. Etc.

This is also a great way to deal with diseased or infested plant matter that can't be composted.

For that matter, depending on how your system is set up, you could also use the food crops after they've been eaten, by pyrolyzing "wastes".

(These are my solutions for making biochar for my land. I don't have enough trees to make it from wood.)

Phil Stevens wrote:Remember that "sequestration" in a carbon crop is only as good as the means of storage. If you're just putting it back into the soil, most of the carbon will be back in the atmosphere in a couple of years. This is not a bad thing in itself, as carbon is vital to soil health and it's all part of the biological cycle. But it's a flow and not a stock. You have to add a similar amount every year to keep soil C levels up, and the amount that is converted to humus is comparatively tiny.

If you're looking at removal of carbon from the cycle, you will need to pyrolyse that corn. Or hemp, switchgrass, miscanthus, or whatever you grew.

Thanks Phil.  Would sun-drying the corn (or allowing it to dry out in a desert-like area) be close enough to pyrolization to keep in the carbon for a few decades?  I am imagining the corn just strewn on the ground and a new crop grown right over it, in a dry and sunny climate.

Travis Johnson wrote:I wish there was a corn subsidy this year as I would have actually gotten it, and the ethanol subsidy was phased out several years ago.

I do not think corn is the evil crop that most people believe it to be though, and was a staple of the pioneers that came to Maine for a lot of good reasons. Those poor saps ate the stuff 3 meals a day, but back then, it really made sense due to how it grows, and where they were planting.

Thanks Travis, and sorry to hear you didn't get a subsidy.  If there were a carbon sequestration subsidy, would that meet your needs as a farmer?  

I also have mixed feelings about corn--I'd never read The Omnivore's Dilemma but the info in there about corn is really inspiring.  I think it's a matter of the way we treat it.  Industrial agriculture can be overkill, but the corn has been a special sacred plant for indigenous people too.

The C4 carbon process is what started the whole line of thinking for me.

If you grew corn with the main goal of capturing the most carbon you could and no other requirements, what might you do differently?

Tyler Ludens wrote:Corn doesn't grow all that well in the desert.  There are other grasses which are better adapted.

For semi-arid areas I like prairie grasses such as Switchgrass.  Also these don't need to be planted each year, being perennials.

I can grow Switchgrass without irrigation or protection from deer.  I can't grow corn that way.

Interesting.  So now I read that switchgrass also has the C4 process.  It seems to capture more energy per hectare than corn.


I'm thinking of robots and fabric air-well things (wakawater) that capture 13-26 gallons a day.  Or grass that's bred for texture in the leaves and stalks that captures more dew somehow. . .so that it can grow in total desert.

Why am I fixated on desert? for the sun drying but more for the "we can't mess it up any more than it already is" factor.  But maybe that is already true of some fields in industrial agricultural areas where the infrastructure is already there but the soil has been so depleted as to be no longer economical.    


from wikipedia:
One study cites it takes from 0.97 to 1.34 GJ to produce 1 tonne of switchgrass, compared with 1.99 to 2.66 GJ to produce 1 tonne of corn.[17] Another study found that switchgrass uses 0.8 GJ/ODT of fossil energy compared to grain corn's 2.9 GJ/ODT.[18] Given that switchgrass contains approximately 18.8 GJ/ODT of biomass, the energy output-to-input ratio for the crop can be up to 20:1.



This means there is some measure of the amount of carbon in the plants...then how you keep that from breaking down is another question, but if the intention is simply to buy time and capture carbon, while other longer term changes are being made by humanity, it would be helpful.

I think the 1.3 GJ needed to produce a tonne of switchgrass may be mostly nitrogen fixation...a one-time cost, and the grass is perennial and self-seeding.  Then there's the tractor for planting, and that can be powered mostly by PV solar.

So far I think switchgrass is the PO corn.

I welcome more thoughts.

Hey Joshua -

Drying the seed and storing it would be an okay sequestration vehicle...as long as the storage was effective. But as soon as something eats the corn (you, mice, bugs, fungi) the carbon gets metabolised and it's back into the loop. Pyrolysis is the only low-tech means we have of removing the carbon from the biological cycle.

What is PO Corn?

Paul

Thanks Phil.  

I'm thinking it could be a quick-and-dirty toehold for greening desert, not in a way that makes it habitable for humans but just for the one function of sequestering carbon.

I hear Eric Toensmeir's gosh I don't think I spelled that right point about stacking functions.  I also think sometimes it helps to unstack functions, at least in the thinking process, to open up new possiblities you wouldn't have thought of if you were stuck in a rut of thinking because of normal constraints.  So saying the corp doesn't have to produce food has already opened up the possibility to me of switchgrass, which I hadn't known about, but because I did this thinking exercise I got he answer from you knowledgeable people to the question I didn't even know to ask previously.

Unstacking functions, you might be able to make some desert switchgrass crops and follow these with perennials that would keep the carbon longer.  You'd have a net gain in sequestered carbon compared to the desert you had there before.  

If that desert now is not a desert but a deserted farm that is serving as a windfarm, you now can stack functions.

This brings to mind a problem with carbon offsets--the planet can't really afford to give any.  We've already spent the carbon, we need to pay back what we already owe.

Another advantage of this line of thinking is that the farm/desert could be really experimental--there's not a need to force solutions, if something goes unexpected, if certain trees in the tree crop fail, it's not a big problem for yields.  As long as something else takes it place, as nature usually finds a way to do (that is, with weeds), you're good enough.  The need is simply to favor things that sequester carbon faster, such as the C4 plants...making use of what's already abundant/making use of the problem (industrial agriculture).

PO rich person could buy up large supplies of the corn market at a premium and pyrolize them or store them somewhere.

Phil Stevens wrote:Hey Joshua -

Drying the seed and storing it would be an okay sequestration vehicle...as long as the storage was effective. But as soon as something eats the corn (you, mice, bugs, fungi) the carbon gets metabolised and it's back into the loop. Pyrolysis is the only low-tech means we have of removing the carbon from the biological cycle.

Hi Paul,

"PO" is just a placeholder word.  It's just a blank.  __ corn will do what I want it to do.  

You use PO in the creative thinking exercise to figure out what goes in the blank.  Is that clearer?

Thanks.

paul salvaterra wrote:What is PO Corn?

Paul

I do not get it. Up

Phil Stevens wrote:Remember that "sequestration" in a carbon crop is only as good as the means of storage. If you're just putting it back into the soil, most of the carbon will be back in the atmosphere in a couple of years.

Not convinced of that.  Prairie grasses created deep soils over some 20,000 years, which we subsequently plowed to grow corn, releasing all that carbon.

Much of the carbon in prairie soils is bound up in living or recently dead stuff, which is why breaking sod and turning it over is so destructive. But there is a lot of black (pyrogenic) carbon in those soils from thousands of years of fire, first from lightning and then managed by First Peoples, which does not go away quickly even when exposed...but it does the land no good when it erodes and ends up at the bottom of the Gulf of Mexico.

There are three broad types of soil carbon: labile, which is the stuff that is actively being decomposed and moving through the cycle; humic, which is the end products of all that decomposition and not really going anywhere unless we abuse the soil; and pyrogenic, which was put there by fire. Prairie soils are fantastic because they have all three types. The labile fraction is the quickest to respond to changes in land use, decreasing if it gets broken and turned, but increasing if we heal the land with growing plants and animals.

Tyler Ludens wrote:Corn doesn't grow all that well in the desert.  There are other grasses which are better adapted.

For semi-arid areas I like prairie grasses such as Switchgrass.  Also these don't need to be planted each year, being perennials.

I can grow Switchgrass without irrigation or protection from deer.  I can't grow corn that way.

This is the exact reason I don't always believe in growing all local food.      It makes sense to grow that which grows best in a location, and ship it to where they can't.

Phil Stevens wrote:Much of the carbon in prairie soils is bound up in living or recently dead stuff, which is why breaking sod and turning it over is so destructive. But there is a lot of black (pyrogenic) carbon in those soils from thousands of years of fire, first from lightning and then managed by First Peoples, which does not go away quickly even when exposed.

Perhaps that black carbon is what I am thinking of when I think of the deep prairie soils - 15 or more feet deep in some places? On the other hand, Prairie grasses can have roots 8-14 feet long - those roots are not turned over during plowing, only the shallower material is.

Joshua,

I like your thinking and I have thought along these lines frequently myself.  I love the idea of some type of plant that would suck up carbon and store it with minimal input.

My own variation on this theme is a type of fine lawn grass that fixes its own nitrogen and has an extremely deep root system.  You mentioned using deserts on the grounds that we cannot screw them any worse than they already are (assuming that we are talking about a true desert like the Sahara).  I was thinking about using the American backyard for the same reasons.  

In my version people would just sprinkle grass seeds over their lawns, the seeds would sprout and send up short but dense blades of grass that rarely if ever needs mowing.  The roots would fix their own nitrogen and never need fertilizer.  The roots would grow deep—like 10-20 feet deep.  This would give them access to deep water during times of drought.  Further, as typically 1/3 of a grass plant’s roots die each year (and are promptly replaced), the grass would take co2 from the air, move it deep underground where it would stay more-or-less permanently locked even after the tissue that moved it underground died.  There the recalcitrant carbon would benefit soil biota, aid moisture retention, loosen up clay soil and add substance to sandy soils.

If we could get millions of homeowners to plant this magical grass we could turn the backyard from something that consumes resources into something that itself serves as a resource.

Just my thoughts,

Eric