Market Farming

[Marcie Rosenzweig <fullcircle AT jps.net>]

I'm cross-posting this because ATTRA is such a great resource.  I urge
y'all to check out not only this publication, but the entire site.

Marcie

>X-Authentication-Warning: shasta.ces.ncsu.edu: majord set sender to
>owner-sanet-mg AT ces.ncsu.edu using -f
>Comments: Authenticated sender is <steved AT ncatark.uark.edu>
>From: "Steve Diver" <steved AT ncatark.uark.edu>
>To: sanet-mg AT ces.ncsu.edu
>Date: Tue, 1 Feb 2000 16:52:54 -0600
>Subject: New: Principles of Sustainable Weed Management for Croplands
>Reply-to: steved AT ncatark.uark.edu
>Sender: owner-sanet-mg AT ces.ncsu.edu
>Precedence: bulk
>
>Announcing this new web item from ATTRA.
>
>Principles of Sustainable Weed Management for Croplands
>http://www.attra.org/attra-pub/weed.html
>
>Abstract:
>
>Weeds are invited guests into agricultural fields as the result of
>management decisions and defying nature's principles. Managing
>croplands in tune with nature's principles makes for fewer and less
>costly weed problems. Strategies which utilize allelopathy,
>intercropping, crop rotations reduce weeds considerably. A weed-free
>design is discussed. A number of other weed control strategies are
>discussed. Additional resources are listed at the end of the
>publication.
>
>The author is Preston Sullivan, agronomy specialist.
>
>As a sampler, I have copied one section below titled "The Root Causes
>of Weeds"
>
>The Root Cause of Weeds
>
>          Have you ever noticed when a piece of land is left fallow
>          that it is soon covered over by annual weeds? If the field
>          is left undisturbed for a second year, briars and young
>          trees start to grow. As the fallow period continues, the
>          weed community shifts increasingly toward perennial
>          vegetation. By the fifth year, the fallowed field will host
>          large numbers of young trees in a forest region, or
>          perennial grasses in a prairie region. This natural
>          progression of different plant and animal species over time
>          is a cycle known as succession. This weed invasion, in all
>          its stages, can be viewed as nature's means of restoring
>          stability by protecting bare soils and increasing
>          biodiversity.
>
>          Weeds are evidence of nature struggling to bring about
>          natural succession. When we clear native vegetation and
>          establish annual crops, we defy ecological succession. Man
>          is, in effect, holding back natural plant succession, at
>          great cost in weed control. To better understand this
>          process, think of succession as a coil spring. Managing
>          cropland as an annual monoculture compresses the spring -
>          leaving it straining to release its energy as a groundcover
>          of weeds. In contrast, a biodiverse perennial grassland or
>          forest is like the coil spring in its uncompressed condition
>          - a state of relative stability with little energy for
>          drastic change (Figure 1) (2). Generally speaking,
>          biodiversity leads to more stability for the ecosystem as a
>          whole.
>
>Monoculture
>(Unstable Simple Community)
>
>Biodiversity
>(Stable Complex Community)
>
>Figure 1. Monoculture vs. Biodiversity
>
>          Modern crop agriculture is typified by large acreages of a
>          single plant type, accompanied by a high percentage of bare
>          ground - the ideal environment for annual weeds to prosper
>          in the first stage of succession. Holding succession at bay
>          with such unstable ecosystems can only be managed with high
>          levels of inputs such as cultivation, mowing, herbicides and
>          fertilizers.
>
>          Having a high diversity of plants and animals increases the
>          stability of the whole system because harm to any one
>          species is less likely under diverse conditions than with
>          less diverse environments. For example, an insect outbreak
>          could wipe out a pure stand of crop because the insects can
>          easily move from one plant to the next and breed rapidly.
>          The insects can find their food easily and have few
>          predators or parasites to hamper them. The same insect
>          invasion occurring in a mixture of many plant types would be
>          less severe on any one type of plant because the insects
>          would have a harder time finding their preferred food. The
>          insects would be undernourished, have more difficulty
>          finding a mate, and have lower reproductive rates. The end
>          result is that the impact of an insect outbreak is much less
>          severe on the whole ecosystem where high biodiversity
>          prevails. Stability through biodiversity is one of nature's
>          fundamental rules.
>===========================================
>
>
>To Unsubscribe:  Email majordomo AT ces.ncsu.edu with the command
>"unsubscribe sanet-mg".  If you receive the digest format, use the command
>"unsubscribe sanet-mg-digest".
>To Subscribe to Digest: Email majordomo AT ces.ncsu.edu with the command
>"subscribe sanet-mg-digest".
>
>All messages to sanet-mg are archived at:
>http://www.sare.org/san/htdocs/hypermail
>

Marcie A. Rosenzweig
Full Circle Organic Farm
Auburn, CA