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Re: Cities/rural--resources (was Yuri receives hypocrite of the week award)



dietz@interaccess.com (Paul F. Dietz) wrote:

>sjol@KingCon.com (Curtis Sjolander) wrote:


>>>Likely, you have done it on relatively small plots of land supported
>>>by inputs of organic wastes (plant or animal) from larger surrounding
>>>areas, with that waste most likely containing nutrients ultimately
>>>derived from chemical fertilizers.

>>All correct except for your last five words... So?

>So: you can't look just at the yield from a particular
>parcel of land, but at the overall average yield.  If
>enriching the soil on your particular plot required setting
>aside more area for green manures or other non-food uses,
>then your average yield, including that other land, is less
>than the yield of just the single plot.

>	Paul

I do not kmow of anyone who calculates crop yield per acre on such a
basis.  If you did attempt to calculate crop yield on this basis, then
you would have to do so consistantly for both large mechanized,
chemistry type production as well as for small scale non mechanized,
non chemical type production.  And if you did, I do not think the
result would be _significantly_ different.  Large agribusiness
concerns use cover crops too.  

However, there are problems with calculating crop yield per acre
including "non crop" land used as a fertility input to the crop land.
One problem is that the "non crop" land may actually be used to
produce another crop.  Another problem is that it may not be entirely
fair to count the "non crop" land as its main purpose may be wholely
divorced from crop production.  There are other problems...

An example: steep hillsides (which should not be used for any row
crops because of erosion concerns in any case) that are kept in grass,
used to feed livestock, and the manure from the livestock is used to
fertilize the crop land (as well as the pasture for the livestock).
Now the yield from the total acerage is the row crop (vegetables or
grain, or ...) PLUS the yield of the livestock products (milk, or meat
or wool..).  So how do you calculate the vegetable yeild per acre in
this example?

Another example:  The fertility for a particular row crop may be
compost made from a combination of leaves collected from suburban
yards and various other organic wastes such as food scraps.  Is it
really fair to count the acreage of those suburban yards (which have
many other uses) in the calculation of yield per acre?  The leaves are
just a waste product (from most homeowners' perspective) of those
suburban yards, not a product of that suburban yard.

Another point is that fertility can be maintained for some crops
without (or with minimal) use of materials gathered from "larger
surrounding areas" by using cover crops interseeded with the main crop
and/or cover crops used in the off season during which the main crop
either can not or traditionally is not grown (yield per acre for a
crop is usually calculated per year or per usual growing season).

I believe that these above mentioned difficulties are why yield per
acre usually is calculated without taking into account "input" acerage
(or inputs in general).

The reality is that ANY farm (huge or tiny or anywhere in between)
that sells product off of the farm, must have inputs onto the farm to
make up for the materials that were sold if the farm is not to be a
simple nutient mining operation.  

The original point is still valid:  Large "modern" mechanized,
chemical using agribusinesses are NOT required to obtain high crop
yields per acre.




--
Curtis Sjolander
sjol@KingCon.com


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