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On Thu, Aug 16, 2007 at 11:21:42AM -0700, James Newtons Massmind wrote:
> > Also what it says about sustainable agricultural practices is 
> > interesting. The researchers probably understand this, but I 
> > doubt the environmental groups that will latch on to this 
> > study do... Organic farming methods actually release far more 
> > aerosols into the air than conventional methods as organic 
> > farming tends to be highly reliant on the very destructive 
> > practice of tilling soil to keep pests and weeds under 
> > control, releasing lots of dust into the air.
> 
> 
> I don't know what most organic farmers do, but what we do is simply cut the
> weeds and let them fall on the ground around the crop plants along with the
> mulch we spread. The result is a "mat" of dead weeds that other weeds can
> not grow through. This mat is NEVER disturbed except to make a small hole
> for the planting of the next crop. Over time, it decomposes and releases the
> nutrients in the weeds, etc.. back into the soil, in effect becoming
> fertilizer. Additional fertilizers are added to the top under a new layer of
> mulch and slowly defuse into the soil. We also "water from the bottom" using
> ollas once the new crop plants are established so there is no water at the
> surface for weeds to drink.
> 
> Google for "no-till gardening" or "lazy gardening" or "green manure" for
> just read:
> http://techref.massmind.org/techref/other/gardens.htm
> 
> We spend almost no time on it. I have no idea why farmers make things so
> difficult.

It's an issue of scale aparently. Your approach works fine for a small
garden, but on larger scales weeds end up growing through that mat just
fine. Cutting weeds is probably very difficult to do on a cost-effective
bases on a large scale, for one weeds tend to quickly evolve to grow
short enough that mowers don't work. I've heard of farmers that *burn*
weeds, but that has it's own issues, and non-organic farming uses
burning technology too. Interestingly in no-till farming the most common
*type* of weed aparently shifts a bit, to much more difficult to remove
fiborous plants. You may also be in an area that's less susceptible to
weeds/pests overall. 

This article mentions the above, and mentions how, for instance, organic
cotton growing is aided by boll weevil eradication programs using
synthetic insecticides, creating a larger area less suseptible to the
boll weevil:

http://www.cgfi.org/publications/organic_myht_pesticide_free_farming


A similar issue is how often when you trace where nutrients are coming
from you find that organic farming is indirectly dependent on chemical
fertilizers. Farming will always remove nutrients from the soil, for the
obvious reason that plants are made up of more than carbon, oxygen and
nitrogen. Organic farming is often heavilly dependent on adding
manure to the soil to make up for that loss. But, where do the nutrients
in the manure come from? Usually from chemical fertilizers, applied
to a nearby non-organic farm...

- -- 
http://petertodd.org
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