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livingontheland - Re: [Livingontheland] soil fertility

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Subject: Healthy soil and sustainable growing

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  • From: "TradingPostPaul" <tradingpost@riseup.net>
  • To: "Douglas Willhite" <drwillhite@earthlink.net>, livingontheland@lists.ibiblio.org
  • Subject: Re: [Livingontheland] soil fertility
  • Date: Sun, 03 Jun 2007 19:16:57 -0600


As usual most people full of themselves still manage to say a lot of
worthwhile things. Warner is typical of the experts who take time-honored
ideas and try to dress them up in scientific language and make them sound
original. What he terms "Whole systems agriculture" is a combination of
practices promoted by the Rodales and many other organic gardeners for the
past several decades. Any credit to the Rodales, however, is conspicuously
missing from his long tome. Does gardening really need "Leibig's Law of the
Minimum"? And Law of Conservation of Matter? And on and on. Personally I
think Warner's criticism of Jeavons' "closed system" is unscientific. A
system that takes in gases from the air and soil and is powered by sunlight
to convert raw materials into food is not strictly a "closed system" at
all.

Great, he's a no-tractor, no tillage market grower. So am I. And of course
you can grow that much on very small garden space. We've talked about that;
Jeavons wrote a great deal on the subject. I agree absolutely with grabbing
composting or mulch materials from outside your property. It's a no-brainer
though; our society trucks so much organic waste to landfills we're running
out of places to bury it. Bury it in the garden where it belongs.

paul tradingpost@lobo.net

*********** REPLY SEPARATOR ***********

On 6/3/2007 at 10:51 AM Douglas Willhite wrote:

>In my years as an agriculture teacher, a science teacher, and a farmer,
>I've
>noticed a great deal of misinformation out there about animal manures and
>compost. Many believe that you can turn a few animals out in a pasture and
>the
>animals, by means of their manure, will make the soil more fertile without
>any
>help from the feed store. .
>
>And when it comes to compost, magical qualities are sometimes attributed
>to it
>that can't be supported by the laws of science. A popular book by John
>Jeavons,
>"How to Grow More Vegetables . . . ", advocates growing "compost crops" on
>garden beds, composting them, and then returning them to the beds with the
>expectation that soil fertility will be sustainably enhanced. For years
>I've
>let the idea of a "closed system" slide without challenge but at this
>point in
>time I feel compelled to come out of the closet. As we know, grim times
>may not
>be far ahead and gardeners who anticipate getting a good portion of their
>food
>from their gardens need to be working with a full-deck of information.
>
>Whole systems agriculture advocates an "open system" to build and maintain
>fertile soil. The principal vehicle for this, in a post-carbon world,
>would be
>to gather mulch from land surrounding one's garden and bring it into the
>garden
>for mulching the beds. My very rough calculations for the amount of land
>required for this go like this. . .
>
>--1/10th acre of intensive bed will supply the subsistence caloric
>requirement
>for 1 person, harvesting 2 crops per year. 1/5th acre would be required if
>the
>climate is such that only one crop can be grown.
>
>--Fertility would be enhanced and maintained by gathering mulch from an
>additional 1/10 acre to one acre of less intensively used land, say from
>urban
>and suburban landscapes, pastoral or wildlands.
>
>Let me review the scientific principles that apply here. . ..
>
>We have, in the first place, the Law of Conservation of Matter. This says
>that
>matter, and more specifically elements, cannot be created or destroyed [at
>least
>in one's backyard] and that matter can only be reorganized into various
>compounds. This means that nothing comes out the back of an animal that
>doesn't
>go in the front and nothing comes out of a compost pile that didn't go
>into it
>as far as the 16 or so essential plant nutrients are concerned.
>
>Then we have Leibig's Law of the Minimum. This states that plant growth
>will be
>limited by the least available nutrient and it further states that one
>nutrient
>element cannot substitute for another. My soil here in Madera, for
example,
>has an a critical shortage of potassium but this will not be made up for
>by the
>abundance of phosphorus. Plant and soil scientists believe that, in the
>end,
>potassium will probably be the most critical element in maintaining soil
>fertility.
>
>Lastly there is the Law of Entropy which could be thought of as "the
>disorganizing force" that always pulls on all that is organized. Each time
>the
>elements of life, that is the 16 or 20 elements required for plant and
>animal
>life, are assembled into plants, then reassembled into animals, then
>remineralized back in the soil, there is a loss. In farms in gardens this
>"leakage" takes place by leaching and erosion whereby the elements become
>widely
>disbursed and unrecoverable. [Liquid fuels are made up of highly organized
>molecules of carbon, hydrogen and oxygen but combustion "disorganizes"
them
>into carbon dioxide and water with the attendant loss of the sun's energy
>that
>went into them.] As we know, it will take a very long time for them to get
>reorganized back into petroleum based fuels.
>
>In the end, agricultural sustainability will be limited by the rate at
>which
>rocks can be weathered into soil and the minerals in those rocks made
>soluble.
>This is why intensive beds alone cannot be relied upon to be sustainable
>regardless of one's skill at making compost. A considerably larger area is
>required to make the minerals in rocks available to plants and I suspect
>that
>even 1 acre per person may not even be enough.
>
>In discussing these ideas with Dr. James Farrar, Plant Science Department
>Head
>at California State University, Fresno , he commented as follows. . .
>
>"You are correct that composting will not add any minerals that are not
>present
>in the animal or plant material. As you know, composting can change the
>nature
>of the organic material and the population of microorganisms present in
the
>compost.
>
>"The only mineral exception is that it is possible to incorporate nitrogen
>into
>the system through the use of legumes. The downside is that that
>legumes--Rhizobium symbiosis--is driven by low nitrogen availability so
you
>have to start with a nitrogen depleted soil in order to get much benefit.
>There
>are also free-living nitrogen fixing bacteria that we are learning more
>about."
>
>Please visit our website at . . .
>
>http://www.wholesystemsag.org
>
>for more good ideas about growing food in the difficult times. A global
>food
>crisis may be at hand. with the USDA predicting only a 53 day supply for
>the
>2007 crop year--half the supply of 1999 and the lowest ever since records
>have
>been kept. Food production per person has been declining for years and the
>fact
>that huge amounts of land are now being used for growing biofuels puts the
>Wolf
>right near the door. Expect substantial food price increases soon if you
>haven't noticed already.
>
>In addition to honing up on gardening knowledge and skill I recommend
>laying up
>a good supply of dry beans and peas. Read more in the Food Security
>section of
>our website.
>
>Good wishes and good growing, all
>
>John Warner
>Madera Whole Systems Agriculture near Fresno, California
>No-tractor, no tillage market growers since 1996
>http://www.wholesystemsag.org
>
>
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