Hello Roberto,
Russ Bullock wrote:
> >another version of this thread) is that when vegetables are grown
> >side-by-side on the same soil (the only difference being fertility)
> >the mineral content _may_ be very close.
>
> Roberto commented:
>But isn't this precisely one difference between organic and chemical
>farming? The organic farmer improves the soil while the chemical
>farmer destroys the soil. You can't therefore insist on "same soil"
>conditions, because the soils will become very different between
>organic farms and chemical farms.
>
>Roberto
Joel comments:
I believe that Russ was suggesting that unless the organic and conventional
plots being compared have the same inherent soil properties (e.g texture
i.e. % sand, silt and clay, clay mineralogy, pedogenic features) measured
differences in crop nutritional content may be the result of inherent soil
differences rather than management induced differences. The study conducted
in the 1950's by Dr. Firman Bear et al. that is often but incorrectly
touted as an organic vs. conventional nutritional quality comparison is
infact an investigation of the relationship between inherent soil
properties and crop nutritional quality.
My recollection is that Bear et al. found that the crops grown on finer
textured soils had high levels of many nutrients than crops grown on
coarser textured soils. Is any one familiar with other studies that have
investigated the relationship between inherent soil properties and crop
nutritional quality ? This is a fundamental agronomic relationship that I
would think would (should) have been studied thoroughly during the first
half of the 20th century.
Joel
Joel Gruver
Visiting Faculty
Principia College
Elsah, Illinois 62028
(618) 374 - 5289
jgruver@principia.edu
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