Skip to Content.
Sympa Menu

permaculture - [permaculture] Fwd: Re: [grazersedge] Re:Green manuring

permaculture@lists.ibiblio.org

Subject: permaculture

List archive

Chronological Thread  
  • From: Mark <mpludwig@facstaff.wisc.edu>
  • To: permaculture@lists.ibiblio.org, midwestpermaculture@yahoogroups.com
  • Subject: [permaculture] Fwd: Re: [grazersedge] Re:Green manuring
  • Date: Mon, 22 Jul 2002 10:18:24 -0500

Folks,
forwarded from my grazing list. Helps to answer some of out prairie vs forest questions.
Mark L



Rick Williams wrote:

> With the apparent large mass of trees in a forest above the ground, but with
> the minimal amount of roots below the ground in a forest, does the forest
> above ground mass wind up back in the carbon cycle by decomposition and most
> go back into the air? I know that former President Reagan was severely
> criticized for saying that trees "pollute" because they return so much
> carbon back into the air. Is it correct that some areas (the Smoky Mountains
> for example) have a haze from this breakdown product that gets in the air?
> Have you any approximate idea of what percentage organic matter is returned
> to the soil by the above ground part of the forest? Then how does that
> compare to prairie? Are both able to build O.M. levels, but the forested
> land is just slower at doing that?
>
> REPLY:

The farm in Illinois lies on the break between prairie and forest in the Driftless Area. The prairie soil has organic matter
content running about 6%. The forested soils run about 2.5% on the soil tests we get back. This is a result of the long term
vegetation growing there, because the parent material is the same, wind blown silt. The depth of the soil and the drainage class
is the same. I also did a special paper on this very subject while attending UW-Stevens Point when the school was still Wisconsin
State University. Also, if you can find a copy of Jenny's "Factors of Soil Formation", you can read about vegetative influences
on soils. Forested soils will never catch up to prairie soils in building soil organic matter. The chemistry of forested soils
versus prairie soils works against organic matter accumulation except at the very surface of a forested soil unless the soil is
very wet to the point of being a swamp or bog. In that instance, the soil is low on oxygen and the organic matter accumulates
since it is not oxidized into carbon dioxide very quickly if at all.


> Isn't it normally done on large scale operations that you grow the organic
> mass on the land and till it in for sheet composting?
>
> REPLY: If you have a high residue crop, like grain corn, you do return a lot of organic matter. If it is tilled in, organic
> matter content tends to be higher than if the corn had been taken off for silage or a low residue crop had been planted
> instead. In the Upper Midwest and the Northeast, high residue crops, such as corn, can maintain rather high levels of soil
> organic matter. Due to the cool climate (on a whole, not right now!) less oxidation of organic matter takes place. Since the
> rate is slower, high residue crops can help maintain or even improve soil organic matter content on tilled soils. However, you
> go further south, Mid-Atlantic states to Missouri and below, the climate is warmer for a longer period of time and each year's
> residue gets pretty much completely decomposed before the end of summer, or sooner depending on moisture levels. In that
> climate, even high residue crops can do little to build organic matter levels if tilled conventionally. Well drained soils in
> the South were naturally low in organic matter before cultivation started so there was little to build on in the first place.

> Perhaps this is a bit off the topic of grazing, but if you were going to do
> moderate scale market gardening (one acre or larger), and you wanted to stay
> "organic," what would you recommend for a practical labor reducing approach
> to weed control. This is our largest problem on our farm.
>
> We heavily mulch potatoes (Ruth Stout method mostly) but have not done this
> with other plants to a great extent. Is it possible to use wood chips as
> long term mulch? I am thinking that we need to mulch to retain moisture,
> make it easier to walk on clay/loam type soils, and not add any weed seeds.
> We have significant amounts of Ashleaf Maple on our property that could be
> run through a chopper/chipper to provide this material. Or are other methods
> better?

REPLY: I would still rely on a hay or straw mulch over wood chips. The wood chips have a very high carbon to nitrogen ratio and
would make the plants nitrogen deficient unless you added some manure to compensate before laying down the chips. The box elder
chips probably would not acidify the soil during breakdown as pine chips would. For potatoes, plant first and then roll out a
large hay bales and let the potatoes come up through. For set plants, it depends on how those are set in the ground. If doing it
by hand with a trowel, roll out a large round bale first, use a sharp tool to cut a hole in the hay, and then proceed with the
trowel. If using a machine like a tobacco planter, then it might be better to use small square bales and use the slabs as formed
by the baler to lay down between rows. No matter what, you are looking at a labor intensive operation compared to the non-organic
way of clean till, plant, and spray. However, if you feel you have a cleaner, safer product that is worth the extra effort, go
ahead. For my two 50 foot rows of potatoes, I squash Colorado potato beatles and their larva by hand rather than spray with an
insecticide. I have noticed wasps sting and take off with the larva too. However, I cannot rely on that as a very effective
biocontrol. A handful of larva killed by wasps when there are a couple of hundred or so on 100 feet of potatoes is not my idea of
economic control, no matter how in tune with nature it might be.

Jim Cropper
Forage Management Specialist


------------------------ Yahoo! Groups Sponsor ---------------------~-->
Access your PC just like Web Mail
http://us.click.yahoo.com/r5uw2C/zncEAA/Ey.GAA/S8XolB/TM
---------------------------------------------------------------------~->

Since time is important, please reduce the number of lines from previous posts you reply to, and use an accurate subject line.
Post message: grazersedge@egroups.com
Subscribe: grazersedge-subscribe@egroups.com
Unsubscribe: grazersedge-unsubscribe@egroups.com
List owner: grazersedge-owner@egroups.com
Our homepage: http://www.egroups.com/group/grazersedge


Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

Mark P. Ludwig
Poultry Research Lab
University of Wisconsin -Madison
608-262-1730 WK
608-846-7125 HM





Archive powered by MHonArc 2.6.24.

Top of Page