Re: Till/noTill (was Composted cow manure/rice nutrientcycles)

From: Steve Diver (steved@NCAT.ORG)
Date: Thu Apr 10 2003 - 13:29:11 EDT


There are benefits and there are limitations to no-till
vegetable production.

It has to do with scale of production, transplanted crops, large
seeded vs tiny seeded crops that require seedbed preparation,
specialized equipment, and weed control.

Weed control is a big factor. Of course herbicides are effective
in conventional no-till, and that is a major reason it has been
adopted so widely. But let's consider sustainable and organic
methods that do not use herbicides. After you create the cover
crop mulch -- through mowing or mechanical disturbance -- weeds
are suppressed pretty darn good for 30-45 days. But Mother
Nature has her own ideas and sends up little tiny weeds through
the mulch. Pretty soon, the little tiny weeds become big, vigrous
weeds. In conventional no-till, post-emerge herbicides are
employed to knock them down.

But these post-emerge weeds are the thing that organic no-till
has yet to completely figure out. If you are growing a few
hundred feet of transplant crops or large-seeded crops like
corn and beans or curcurbits, you can simply pull emerging weeds
by hand. There are some organic market gardeners managing
no-till beds with deep mulch and hand weeding, for example.

But that is not feasible or practical on acres and acres of
production. Yet, I challenge farmers and researchers
to figure out non-chemical weed control methods for
large-scale cropping systems done with no-till and low-till.

Here's a resource from Seth Dabney I want to share,
it is excellent.

Dr. Seth Dabney with the USDA-ARS National Sedimentation
Laboratory in Oxford, MS, put together this slide show.

Managing Cover Crops and Green Manures
Seth Dabney, USDA-ARS National Sedimentation Laboratory
http://www.sedlab.olemiss.edu/uep_unit/projects/cover_crops/index.html

Of special interest are the photo images of the mechanical
roller-crimpers. These are the devices that have revolutionized
no-till agriculture in South America.

For a parallel web link to the vast adoption of no-till down
in South America, see:

No-Tillage by Rolf Derpsch
http://www.rolf-derpsch.com/notill.htm

In addition, there is a classic paper by Ron Morse on the use
of transplant equipment in association with high-residue
cover crop mulches in no-till vegetable production.

Affordable Small-Scale Equipment for Production of Transplanted
Vegetables in High-Residue, No-Till Farming Systems
Ronald Morse, Department of Horticulture, Virginia Tech
http://vric.ucdavis.edu/issues/bulletinboard/soilconf/afford.pdf

Morse has several publications and reports on no-till vegetable
production, on the web and in print, which provide the most
developed and detailed examination of commericial-scale
production.

The USDA bulletin by Aref Abdul-Baki and John R. Teasdale
is notable, as well. Yet, this is a hybrid no-till system, in my
view. Seedbed preparation in the fall is done with thorough
tillage for excellent seed establishment, accomplished with a
Brillion seed drill which is top of the line equipment. You really
need excellent winter cover crop establishment in the fall to
achieve these high biomass cover crops in the following spring.
It is in the Spring that a flair mower or mechanical crimper is
employed to create the high residue, no-till mulch. It is followed
with post-emerge herbicides for touch-up weed control.

Sustainable Production of Fresh-Market Tomatoes and
Other Summer Vegetables With Organic Mulches
USDA Farmers' Bulletin No. 2279. 23 p.
http://www.ars.usda.gov/is/np/tomatoes.html

George Kuepper at ATTRA put together a special "Organic
Matters" series of publications. The title below is a perfect
resource for any discussion on no-till methods and
considerations in organic farming.

Pursuing Conservation Tillage Systems for Organic Crop
Production
George Kuepper, ATTRA
http://attra.ncat.org/attra-pub/organicmatters/conservationtillage.html

Nancy Creamer's work in Ohio and North Carolina using
the undercutter blade for no-till vegetable production is the
other notable item in a discussion of organic and sustainable
no-till production systems.

There are two papers in American Journal of Alternative
Agriculture, written by Nancy Creamer and Seth Dabney,
that are really valuable.

Creamer, N., et al. 1995. A method for mechanically killing
cover crops to optimize weed suppression. American Journal
of Alternative Agriculture. Vol. 10, No. 4. p. 157-162.

Creamer, Nancy G. and Seth M. Dabney. 2002. Killing cover
crops mechanically: Review of recent literature and assessment
of new research results. American Journal of Alternative
Agriculture. Vol. 17, Issue 1. p. 32-40.

I figure these items are helpful in the sustainable and organic
no-till discussion. No-till vs Full-till is relative to each farmer's
situation. Steve Groff in Pennsylvania and John Luna in Oregon
have useful no-till and low-till resources, as well.

Regards,
Steve Diver




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