1)Organic?

2. Organic no till?

3. Biochar? Even with it reducing other carbon absortion is it a net sequestration?

Very valuable.

These are only my personal opinions.

Time to scrap no-till farming as a carbon offset or greenhouse-gas mitigation strategy.

Biological systems are complicated and we as a society have paid little attention to them.

To me this issue looks like the usual: wanting quick, simple answers for our immediate needs. Nature is jealous of her secrets and does not reveal them readily.

Bart
Energy Bulletin

The evidence is turning against biofuels it would seem.

-David Ahlport

Hmmm, I thought the carbon advantage in no-till was in not running a giant diesel-powered tiller around for a few miles (figuring that even an automated tractor-carried seed drill set up must use a lot less energy than something that plows all that ground).  Can someone explain this "tilling" and then distinguish it from "no-till" for the benefit of those of us without the farm experience?

This is from extensive reading, not personal experience, but:

1. Non organic no-till substitutes massive herbicides for tilling, which saves energy, (even counting the energy in the herbicide) but is horrible for the environment in other ways.

2. Organic no-till typically rolls the weeds into the ground in a way that kills them and buries them shallowly without disturbing the roots. This still saves energy compared to a plow, especially since the roller can be in the front and the see dispenser in back of the same tracker - so only one trip not two, and not pulling a heavy plow.

4) There is a separate claim that no-till sequesters more carbon in the soil than plowing - separate from and above energy savings. That is the claim the study rebutted. The study was very careful to say that no-till saves energy and reduces soil erosion (also water use).

1. It would keep organic carbon in the soil, and prevent it from decomposing, and leaking into the air

2. You could chop down all the crops above-land and turn that into biomass.

The first point is nearly the entire argument that people like Michael Wang make to argue the greenhouse benefits of cellulosic ethanol.

The second point is nearly the entire argument that David Perlack makes to say that we have plenty of "waste" biomass to go around.

Without this talking point, their arguments go from weak, to pathetic.

_

If you want some deep reads on no-till, might I suggest this this and this
http://greyfalcon.net/peaksoil
http://greyfalcon.net/cellulosics.pdf
http://www.stopbp-berkeley.org/CellulosicBiofuels.pdf

-David Ahlport

JMG: 3)All forms of no-till save plowing energy fertilizing energy (since no-till reduces or eliminates the need for nitrogen fertilizer.

Yeah, but removing the stalks/etc from the field vastly increases the need for nitrogen fertilizer.

The removal of organic residues from fields will require greater use of nitrate fertilisers, thus
increasing nitrous oxide emissions, nitrate overloading and it's devastating impacts on
biodiversity, on land, in freshwater and in the oceans. It is also likely to accelerate topsoil losses.
http://greyfalcon.net/cellulosics.pdf

#2:
 Organic no-till is still under development and probably will not be used in large acreage extensive production of corn or wheat.  It rolls a cover crop down which smothers many weeds and protects the soil from erosion

#3
 No-till surely does not eliminate the need for nitrogen fertilizer - their is no substitute for the need for nitrogen in productive agriculture.

#4
 No-till saves soil, first and foremost.  Whether is sequesters C, no-till is still recommended for its soil saving benefits, not to mention less diesel use.


WSU Agricultural Systems Educator

No-till can eliminate the need for external nitrogen in organic farming.  As you say, rolling stalks into the field keeps some nitrogen in the soil and reduces the need for it on its own. If you do a long rotation with a grain, a legume, a fiber crop and green manure in a no-till system you can completely eliminate the need for external nitrogen fertilizers as was actually demonstrated in the "old rotation" on a no till fields in a three year rotation of cotton, corn, soybeans, rye grass and and a leguminous grass.  If you can do no-till without added nitrogen with cotton you can do no-till without added nitrogen with most crops. Whether we will is another question. After all we have lots of manure to dispose of, and composted that makes a great nitrogen source and an organic nitrogen addendum.  But it is important to note that organic farmers (both no-till and conventional) often see compost as a supplementary source of nitrogen, using green manures as the main source. (Green manure is when you cultivate a leguminous plant that fixes nitrogen and then plow or (in no till) roll it into the soil.) Often organic farming also using cover crops that are non-leguminous but are plowed or rolled back into the soil. This does not add nitrogen but outcompetes weeds, preserves nutrients and helps builds soil structure.

Incidentally, while carbon fixing has been used to "sell" no-till, it was originally intended as a way to prevent erosion and save labor, not as a carbon fixer.

And the hell massive use of herbicides does not harm the environment. Conventional no-till does increase use of herbicides over conventional industrial agriculture,especially round-up. Run-off of round-up and similar herbicides does a lot of harm. Mind you there is a spectrum between conventional no-till and organic. There are some examples of low-input no-till that is not quite organic, but uses long rotation and other techniques borrowed from organic farming to reduce  herbicides and fertilizer use by 90% compared to conventional agriculture. That may indeed be  more like using asprin than heroin.