Study concludes no-till farming in corn belt states can produce significant Carbon sequestration

[JohnWxy]

Which results in dramatic reductions in GHG emissions from cultivated fields (this applies to any crop to varying degrees)


Carbon sequestered per ha per yr:                 377 to 681 kg C under no-till method

Carbon equiv GHG emissions per ha per yr: 260 to –922 g CO2 eq. under no-tillage

REsearch by Kim and Dale, University of MIchigan
Published in Biomass and Bioenergy, Vol. 28, no. 28, May 2005

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V22-4FBWHB6-1&_user=10&_coverDate=05%2F01%2F2005&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=4bb3623690539a88ab7c52f26c473dae


Nonrenewable energy consumption and greenhouse gas (GHG) emissions associated with ethanol (a liquid fuel) derived from corn grain produced in selected counties in Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin are presented. Corn is cultivated under no-tillage practice (without plowing). The system boundaries include corn production, ethanol production, and the end use of ethanol as a fuel in a midsize passenger car. The environmental burdens in multi-output biorefinery processes (e.g., corn dry milling and wet milling) are allocated to the ethanol product and its various coproducts by the system expansion allocation approach.

The nonrenewable energy requirement for producing 1 kg of ethanol is approximately 13.4–21.5 MJ (based on lower heating value), depending on corn milling technologies employed. Thus, the net energy value of ethanol is positive; the energy consumed in ethanol production is less than the energy content of the ethanol (26.8 MJ kg−1).

In the GHG emissions analysis, nitrous oxide (N2O) emissions from soil and soil organic carbon levels under corn cultivation in each county are estimated by the DAYCENT model. Carbon sequestration rates range from 377 to 681 kg C ha−1 year−1 and N2O emissions from soil are 0.5–2.8 kg N ha−1 year−1 under no-till conditions. The GHG emissions assigned to 1 kg of ethanol are 260–922 g CO2 eq. under no-tillage.

Using ethanol (E85) fuel in a midsize passenger vehicle can reduce GHG emissions by 41–61% km−1 driven, compared to gasoline-fueled vehicles. Using ethanol as a vehicle fuel, therefore, has the potential to reduce nonrenewable energy consumption and GHG emissions.

[jpak]

1. but...but...but...ethanol is a Bad Thing

everyone knows this...

:evilgrin:

[JohnWxy]

2. yeah, along with those who are sure there is an alien body at WPAFB.

:shrug:

[fasttense]

3. How do you no till farm exactly?

Do you poke a hole in the dirt and put a seed in? Seriously, I read a book about this type of gardening about four years ago. Is it the same?

[JohnWxy]

4. not being a farmer I can't really give you a good answer to this question.

Even with conventional tilling I don't think there is as much "plowing up" of the soil as we non-farmers think there is. but NO-till farming I believe, involves less operation of machinery on the fields and yes, less distrubance of the soil. Even with conventional till farming I believe seeds and fertilizer are put into the ground with a multiple disc device which disrupts the soil much less than the image of a plow that we non-farmers have (with considerable turning over of the soil).

Here is a link for info on no-till farming:

http://en.wikipedia.org/wiki/No-till_farming


Maybe somebody with actual farming experience could enlighten us.

[GliderGuider]

5. Corn ethanol production is not sustainable.

The EROEI presented in this abstract ranges from 2:1 to 1.25:1. The production of plant ethanol reduces soil fertility, uses up ground water and competes directly with food for arable land, impacts food production. That pig is going to take a lot more lipstick than this.

Terra Preta processes can produce fuel through biomass gasification and replenish the soil by by burying charcoal, while simultaneously sequestering carbon at up to 150 tonnes/ha, compared to 0.3 to 0.7 tonnes/ha for no-till (as per your abstract).

http://www.worldchanging.com/archives/004815.html:

Claims for biochar's capacity to capture carbon sound almost audacious. Johannes Lehmann, soil scientist and author of Amazonian Dark Earths: Origin, Properties, Management, believes that a strategy combining biochar with biofuels could ultimately offset 9.5 billion tons of carbon per year-an amount equal to the total current fossil fuel emissions!

Compared to unsustainable ethanol production, Terra Preta type processes actually improve the soil's productivity over time while providing fuel and sequestering carbon. Tell me why ethanol is a better idea than this?

[jpak]

6. Ugh

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x82577

[GliderGuider]

7. The abstracts all identify sustainability as a "challenge" rather than a reality

Right off there is one comment on the Science page that makes me suspicious of their actual grasp of the concept: "Most of the "new renewable energy sources" are still undergoing large-scale commercial development, but some technologies are already well established. These include Brazilian sugarcane ethanol, which, after 30 years of production, is a global energy commodity that is fully competitive with motor gasoline and appropriate for replication in many countries." The reason this raises my hackles is that it is well known that Brazilian sugar cane production is depleting the soils due to the wholesale removal of organic material from the already poor soil.

The casual oxymoron "sustainable development" was also thrown around in a couple of abstracts as though it had some meaning. Let's take a look at some axioms of sustainability (per Heinberg):

To be sustainable, the use of renewable resources must proceed at a rate that is less than or equal to the rate of natural replenishment.

To be sustainable, the use of non-renewable resources must proceed at a rate that is declining, and the rate of decline must be greater than or equal to the rate of depletion.

The production of plant biofuels could become sustainable. This would require that the exogenous process energy is entirely derived from renewable and sustainable sources that themselves have significantly positive net energy, that the soil is remediated by the process by more than just the application of nitrogen fertilizer, and that all waste products are environmentally beneficial (or at worst neutral - if such a thing as "environmental neutrality" even exists). This may be possible, but to argue that it will come about in the near future seems to me to be arguing in the face of the facts.

There is at least one technology available to provide renewable, sustainable and environmentally ethical energy. Terra Preta is better than ethanol on all counts.

[jpak]

8. How does one make Terra Preta?? - oh, I know, burn forests for charcoal

Does it displace fossil fuels (and subsequent CO2 releases)???

(nope)

Has there ever been a peer reviewed study on the net carbon balance of Terra Preta systems (forest clearing and wood kilning for charcoal production)???

We must destroy the rain forest to save it???

(could be)

[GliderGuider]

9. Take a look at Eprida's web site

http://www.eprida.com/home/index.php4

You don't "burn down forests" to make it. The proposal is to cultivate coppice willow and poplar, fast growing trees that pull carbon out of the air. You don't cut or burn existing forests for it. As with any such process care is needed to ensure that the practice lives up to its potential. at least in this case the potential seems to be much greater than simply displacing fossil fuels (which is a forlorn hope anyway, on a global scale).

[jpak]

10. Looks like they are growing corn for *ahem* biofuels

:evilgrin:

[GliderGuider]

11. Where do you see that they propose to use corn?

Were you perhaps misled by the photograph on the main page which shows the effects of their carcoal-based fertilizer on corn growth?

The process works best with cellulose, not starch. Their proposal suggests the use of agricultural waste materials or forestry by-products, though any woody product will work.

[jpak]

12. That's what the web site said

BTW I'm a fan of Terra Preta

Just wanted to yank your chain on the "unsustainable corn" comment...

:evilgrin:

[Porcupine]

13. All orchards have substantial pruning waste on a yearly basis...

as well as root boles from trees that are wind knockdowns or are removed for orchard renewal. Currently the farmers in my area just pile this stuff up and burn it when it rains losing all the value of both fuel and biochar. The same kind of pruning happens in vineyards although on a lesser scale. Integration of orchard waste with Terra Preta systems would improve local soil fertility and provide a side stream of income for farmers.

Also my little city produces mountains of tree prunings that are chipped and composted at present. If a portion of the input to the local compost facility was converted to Terra Preta char substantial carbon sequestration would happen. Who prunes the trees in your city?

Thanks for posting this info. Do you know how to get stuff into the research forum?

[JohnWxy]

16. from eprida's web-site:

To make charcoal, wood is heated with limited oxygen, traditionally in a slow burning heap. With modern technology low temperature charcoal can instead be made by a hybrid pyrolysis process whereby biomass such as wood chips or agricultural waste is heated in a sealed vessel.

[Porcupine]

14. Thinning is desperately needed in national forests

I live between Lassen and Mendocino national forests. A local problem is that the second growth forests are hugely overgrown with small trees and brush. Removing these ladder fuels is desperately needed if we are to interrupt the fire cycle and transition our forests to mature, timber producing, old growth stands before the inevitable fire happens. I know places where you literally cannot step between the tree trunks next to the road due to overgrowth.

Using the cycles demonstrated funds could be produced to thin the forests by means of bio-diesel/bio-char production. The ability to get a useful product out of young, growing forests without removing prime timber/old growth structures presents a way of saving the planet AND providing jobs in rural areas that are struggling in the Pacific Northwest.

Next time there is a big storm in your area look at the tree service trucks and imagine all that mass being returned as diesel and carbon fertilizer.

[JohnWxy]

17. I've heard the alien body has been moved to Area 51. I thought you'd want to know.

[Name removed]

18. Deleted message

Message removed by moderator. Click here to review the message board rules.

[JohnWxy]

19. I don't want you to think I am dismissing this Terra Preta out of hand -for Carbon sequestration

it sounds interesting and like it's worth investigating. But how much biomass feedstock is necessary to produce 150 tons/ha and how much land area is required to produce it? Then what is the cost of producing this charcoal and possible fuel? - don't forget there is capital costs for the equipment to accomplish this. My first thought is that heating a large quantity of biomass (150 tons of char would require 600 tons of biomass (Day's project producing 25kG from peanut shells *) - of course this depnds on the type of biomass) to several hundred degrees for several hours (?) requires a good deal of heat and that costs money.


I looked at the web-site you referenced and when it comes to talking about the cost of producing the charcoal by a pyrolytic process it seems a bit vague.

PErhaps these cost data are lacking because the only demonstration project is a 25 kilogram set-up in Georgia (the costs of this example were not mentioned). There is a lot of talk about how much charcoal can be produced but little to no information on what it costs to produce it.

Keep in mind, the study I referenced (above) is talking about growing a crop which produces food (in the form of a feed suplplement for cattle) as well as fuel and sequesters carbon.

When you talk about producing charcoal and fuel (hydrogen?) you are talking about what at this stage is a hypothetical while corn based ethanol is producing food (in the form of a feed supplement for cattle) and fuel right now. IT will be interesting to see what can be learned from a real demonstration project so we can see some real world numbers on costs to produce the charcoal from biomass sources and fuel.

In the mean time, I think we better keep producing ethanol rather than stop that and wait for the hope of something which might prove itself and could be developed in the future.

I don't think a hypothetical proposition beats an actual working technology.



* "Day’s pilot plant processes 10 to 25 kg of Georgia peanut hulls and pine pellets every
hour. From 100 kg of biomass, the group gets 46 kg of carbon — half as char"

[GliderGuider]

20. We disagree on whether the technology of corn ethanol is actually "working"

You can shove fertilizer, seed and water in one end of the process and get ethanol out the other, but we both know the story is a lot more complicated than that. Whether a process can be considered to work or not depends a lot on the system boundary definitions.

I also agree that Terra Preta is at the moment a research project, and the devil is always in the details. It deserves more investigation than it seems to be getting at this point, though. BTW, the process heat is obtained from a portion of the gases given off during pyrolysis. It's just like making charcoal, except you try to be more efficient about it.

[JohnWxy]

21. for more info on ethanol you may want to consult the works of:

Michael Wang, Argonne National Laboratory

Kim and Dale, Michigan State University

Hosein Shappouri, US Dept of Agriculture

Dale has used what is called the system expansion approach to the displacement method of coproduct allocation.

I feel satisfied that these individual's have arrived at valid and credible evaluations of ethanol's efficiency.


In addition to the works of these individuals one should also be aware of technological developments in not only the production of ethanol but also in the area of ICE design. For example:

Iowa State University was granted a patent for commercial development of a process using ultra-sound (to reduce particle size in the corn slurry in preparation for fermentation) which Iowa State researchers have developed which increases alcohol yield 30%.

Carnegie Mellon engineers have designed equipment for processing corn into ethanol which reduces thermal energy inputs required by 60%.

MIT engineers have developed and are now working with Ford Motor Co. to mass produce (by 2011) a Ethanol Direct Injection engine that reduces gasoline consumption by 30%. It does this while only using a 5% ethanol proportion to 95% gasoline proportion. Thus, if all cars were using this engine the total gasoline demand would be reduced 30% while using an ethanol supply that would be only 5% of the total fuel supply.

Ethanol will reach 5% of the total fuel supply (for cars and light trucks) in a 2 to 3 years.

Closed loop ethanol plants (using cattle poop for fuel - using an anaerobic digester to make methane from the cow poop.) are being built (one has started operation in Nebraska) which vitrually eliminate fossil fuel inputs to the corn to ethanol conversion process. Since most of the GHG contribution for ethanol is due to use of fossil fuels in the ethanol plants these plants will dramatically reduce the GHG profile of ethanol. MOre of these plants will be built in the future.

[Doondoo]

15. bump