craig k harris
department of sociology
michigan state university
429b berkey hall
east lansing michigan 48824-1111
tel: 517-355-5048
fax: 517-432-2856
> ----------
> From: Douglas Hinds[SMTP:dmhinds@acnet.net]
> Sent: Friday 22 May 1998 9:55 PM
> To: Sean Clark
> Cc: Sheryl N. Swink; sanet-mg@shasta.ces.ncsu.edu
> Subject: Re: How does organic differ from sustainable ag?
>
> Good data and perspective, but yield and monetary cost differences are
> only part
> of the picture. Were any studies included on nutritional content and
> / or animal
> health? (Regarding the latter, obviously I'm referring to studies
> done on animal
> groups raised exclusively on food cultivated one way or the other).
> Another
> interesting area would be physical, mental and psychological
> performance of
> individuals and groups fed products cultivated under different
> systems.
>
> These are all relevant factors. Quantifying "Quality of Life" in
> concrete terms
> is a real issue and unfortunately, those who aren't personally
> familiar with the
> effects of consuming a diet based on fresh picked, biologically
> cultivated food
> have little basis for comparison. For the figures to reflect real
> meaning,
> comprehensive criteria must be applied. In short - the juries still
> out because
> the research is still far from complete. In fact, many significant
> variables
> have yet to be plainly identified.
>
> DH
>
> Sean Clark wrote:
>
> > At 05:32 PM 5/22/98 -0500, Sheryl Swink wrote:
> > >How about it, fellow sanet-mg folks? Do you, especially those who
> are
> > >producers (not just consumers, researcher/extensionists, and
> interested
> > >digesters like myself), find that this is a generalizable fact? Or
> has it
> > >become a myth? What is the current state of affairs in terms of
> yield
> > >comparisons between organic and conventional methods? Are there now
> > >reliable organic practices by which farmers are regularly attaining
> or
> > >surpassing expected conventional yields onece past the transition
> stage?
> > >Anyone have any current research data/references to address this
> issue?
> > >
> >
> > Sheryl,
> >
> > Organic crop yields are sometimes lower than conventional yields due
> to
> > inadequate (N) nitrogen availability or excessive weed competition,
> > particularly during the transition, but this really depends on alot
> of
> > interacting and site-specific factors. Stanhill (1990) reviewed
> about 200
> > studies comparing organic and conventional cropping systems in
> Europe and N.
> > America and found that organic yields averaged about 9-10% less.
> This is an
> > interesting and important finding but may not tell you much about a
> specific
> > region or crop due to geographic differences in soils, climate, pest
> > pressures, farmer experience and support, market demands, etc. The
> results
> > of studies coming out since then have been variable.
> >
> > At the Sustainable Agriculture Farming Systems (SAFS) project at the
> > University of California at Davis, we've had lower organic corn and
> tomato
> > yields (compared to conventional years) in some years due to N
> > immobilization by soil biota and weed pressure. However, bean yields
> have
> > often been higher under organic management.
> >
> > Nitrogen mineralization/immobilization is sometimes less predictable
> in
> > organic systems and may present problems for crops with high N
> demands, such
> > as corn. However, after 10 years of farming organically these soils
> have
> > been pretty consistent in supplying adequate N. Last year we had a
> weed
> > problem in the organic corn plots. Crow damage at germination
> resulted in
> > poor stands in the organic and conventional treatments.
> Consequently, weed
> > pressure was high due to the gaps. Herbicides were used in the
> conventional
> > system to prevent yield loss but no economically feasible control
> options
> > were available in the organic system once the corn was too high to
> cultivate.
> >
> > Organic tomato yields at the SAFS site have equalled conventional
> yields
> > over the last few years. Weeds can be hand hoed out of this
> high-value crop
> > and other pest groups (insects, nematodes, and diseases) are not a
> problem.
> > This is not the case in the eastern U.S., however, where diseases
> can be a
> > real problem in the humid climate.
> >
> > Overall, the findings of the SAFS project indicate that equal crop
> yields
> > can eventually be achieved in this area with organic methods but
> that
> > economic risk may be greater, particularly during the transition,
> and
> > production costs may be higher, depending upon the crop.
> >
> > Stanhill 1990. The comparitive productivity of organic agriculture.
> > Agriculture Ecosystems & Environment 30: 1-26.
> >
> > M. Sean Clark
> > Research Manager
> > Sustainable Agriculture Farming Systems Project
> > Department of Agronomy and Range Science
> > University of California
> > Davis, CA 95616
> > msclark@ucdavis.edu
> > TEL:(530) 752-2023
> > FAX:(530) 752-4361
> >
> > To Unsubscribe: Email majordomo@ces.ncsu.edu with "unsubscribe
> sanet-mg".
> > To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the
> command
> > "subscribe sanet-mg-digest".
>
>
>
>
> To Unsubscribe: Email majordomo@ces.ncsu.edu with "unsubscribe
> sanet-mg".
> To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command
> "subscribe sanet-mg-digest".
>
To Unsubscribe: Email majordomo@ces.ncsu.edu with "unsubscribe sanet-mg".
To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command
"subscribe sanet-mg-digest".