Teaming with Microbes

This is most of the first chapter. Please offer critics. Right now, this book (Teaming with Microbes) and "Omnivore's Dilemma" seem to give the clearest sense of the direction that gardening and farming should be going to get us off the dependancy on petroleum based pesticides and fertilizers. Again, thank to whoever turned me on to this book.
Teaming with Microbes by Jeff Lowenfels and Wayne Lewis
Chapter 1
What Is the Soil Food Web and Why Should Gardeners Care?
Plants are in control
Most gardeners think of plants as only taking up nutrients through root systems and feeding the leaves. Few realize that a great deal of the energy that results from photosynthesis in the leaves is actually used by plants to produce chemicals they secrete through their roots. These secretions are known as exudates. A good analogy is perspiration, a human's exudate. Root exudates are in the form of carbohydrates (including sugars) and proteins. Amazingly, their presence wakes up, attracts, and grows specific beneficial bacteria and fungi living in the soil that subsist on these exudates and the_ cellular material sloughed off as the plant's root tips grow. All this secretion of_ exudates and sloughing-off of cells takes place in the rhizosphere, a zone immediately around the roots, extending out about a tenth of an inch, or a couple of millimeters (1 millimeter = 1/25 inch). The rhizosphere, which can look _like a jelly or jam under the electron microscope, contains a constantly changing mix of soil organisms, including bacteria, fungi, nematodes, protozoa, and_ even larger organisms. All this life" competes for the exudates in the rhizosphere, or its water or mineral content.
At the bottom of the soil food web are bacteria and fungi, which are attracted to and consume plant root exudates. In turn, they attract and are eaten_ by bigger microbes, specifically nematodes and protozoa (remember the_ amoebae, paramecia, flagellates, and ciliates you should have studied in biology?), who eat bacteria and fungi (primarily for carbon) to fuel their metabolic_ functions. Anything they don't need is excreted as wastes, which plant roots are readily able to absorb as nutrients. How convenient that this production of_ plant nutrients takes place right in the rhizosphere, the site of root-nutrient_ absorption. At the center of any viable soil food web are plants. Plants control the food_ web for their own benefit, an amazing fact that is too little understood and_ surely not appreciated by gardeners who are constantly interfering with Nature's system. Studies indicate that individual plants can control the numbers_ and the different kinds of fungi and bacteria attracted to the rhizosphere by the exudates they produce during different times of the growing season, populations of the rhizosphere bacteria and fungi wax and wane, depending on the nutrient needs of the plant and the exudates it produces.
Soil bacteria and fungi are like small bags of fertilizer, retaining in their_ bodies nitrogen and other nutrients they gain from root exudates and other _organic matter (such as those sloughed-off root-tip cells). Carrying on the _analogy, soil protozoa and nematodes act as fertilizer spreaders" by releasing ,_the nutrients locked up in the bacteria and fungi fertilizer bags." The nematodes and protozoa in the soil come along and eat the bacteria and fungi in the,_ rhizosphere. They digest what they need to survive and excrete excess carbon_ and other nutrients as waste.
Left to their own devices, then, plants produce exudates that attract fungi_ and bacteria (and, ultimately, nematodes and protozoa); their survival depends on the interplay between these microbes. It is a completely natural system, the very same one that has fueled plants since they evolved. Soil life provides the nutrients needed for plant life, and plants initiate and fuel the cycle_ by producing exudates.
Soil life creates soil structure
The protozoa and nematodes that feasted on the fungi and bacteria attracted_ by plant exudates are in turn eaten by arthropods (animals with segmented_ bodies, jointed appendages, and a hard outer covering called an exoskeleton). Insects, spiders, even shrimp and lobsters are arthropods. Soil arthropods eat_ each other and themselves are the food of snakes, birds, moles, and other animals. Simply put, the soil is one big fast-food restaurant. In the course of all_ this eating, members of a soil food web move about in search of prey or protection, and while they do, they have an impact on the soil.
Bacteria are so small they need to stick to things, or they will wash away; to_ attach themselves, they produce a slime, the secondary result of which is that_ individual soil particles are bound together (if the concept is hard to grasp,_ think of the plaque produced overnight in your mouth, which enables mouth_ bacteria to stick to your teeth). Fungal hyphae, too, travel through soil particles, sticking to them and binding them together, thread-like, into aggregates.
Worms, together with insect larvae and moles and other burrowing animals, move through the soil in search of food and protection, creating path-_ways that allow air and water to enter and leave the soil. Even microscopic_ fungi can help in this regard (see chapter 4). The soil food web, then, in addition to providing nutrients to roots in the rhizosphere, also helps create soil_ structure: the activities of its members bind soil particles together even as they_ provide for the passage of air and water through the soil.
Soil life produces soil nutrients
When any member of a soil food web dies, it becomes fodder for other members of the community. The nutrients in these bodies are passed on to other_ members of the community. A larger predator may eat them alive, or they may _be decayed after they die. One way or the other, fungi and bacteria get involved,_ be it decaying the organism directly or working on the dung of the successful_ eater. It makes no difference. Nutrients are preserved and eventually are retained in the bodies of even the smallest fungi and bacteria. When these are in_the rhizosphere, they release nutrients in plant-available form when they, in_ turn, are consumed or die.
Without this system, most important nutrients would drain from soil. Instead, they are retained in the bodies of soil life. Here is the gardener's truth: when you apply a chemical fertilizer, a tiny bit hits the rhizosphere, where it is absorbed, but most of it continues to drain through soil until it hits the water table._ Not so with the nutrients locked up inside soil organisms, a state known as immobilization; these nutrients are eventually released as wastes, or mineralized._ And when the plants themselves die and are allowed to decay, the nutrients they_ retained are again immobilized in the fungi and bacteria that consume them.
The nutrient supply in the soil is influenced by soil life in other ways. For example, worms pull organic matter into the soil, where it is shredded by_ beetles and the larvae of other insects, opening it up for fungal and bacterial_ decay. This worm activity provides yet more nutrients for the soil community.
Healthy soil food webs control disease
A healthy food web is one that is not being destroyed by pathogenic and_ disease-causing organisms. Not all soil organisms are beneficial, after all. As_ gardeners you know that pathogenic soil bacteria and fungi cause many plain_ diseases. Healthy soil food webs not only have tremendous numbers of individual organisms but a great diversity of organisms. . . . Perhaps 20,000 to 30,000 different species make up its billion bacteria-a healthy population in numbers and diversity. A large and diverse community controls troublemakers. . . . they compete with them for exudates and other nutrients, air, water,_ and even space. If the soil food web is a healthy one, this competition keeps the_ pathogens in check; they may even be outcompeted to their death.
Just as important, every member of the soil food web has its place in the_ soil community. Each, be it on the surface or subsurface, plays a specific role._ Elimination of even just one group can drastically alter a soil community. . . . . A healthy soil_ food web won't allow one set of members to get so strong as to destroy the web._ If there are too many nematodes and protozoa, the bacteria and fungi on_ which they prey are in trouble and, ultimately, so are the plants in the area.
And there are other benefits. The nets or webs fungi form around roots act_ as physical barriers to invasion and protect plants from pathogenic fungi and_ bacteria. Bacteria coat surfaces so thoroughly, there is no room for others to attach themselves. If something impacts these fungi or bacteria and their numbers drop or they disappear, the plant can easily be attacked.
Special soil fungi, called mycorrhizal fungi, establish themselves in a symbiotic relationship with roots, providing them not only with-physical protection but with nutrient delivery as well. In return for exudates, these fungi provide water, phosphorus, and other necessary plant nutrients. Soil food web _populations must be in balance, or these fungi are eaten and the plant suffers.
Bacteria produce exudates of their own, and the slime they use to attach to_ surfaces traps pathogens. Sometimes, bacteria work in conjunction with fungi_ to form protective layers, not only around roots in the rhizosphere but on an_ equivalent area around leaf surfaces, the phyllosphere. Leaves produce exudates that attract microorganisms in exactly the same way roots do; these act_ as a barrier to invasion, preventing disease-causing organisms from entering_ the plant's system. Some fungi and bacteria produce inhibitory compounds, things like vitamins and antibiotics, which help maintain or improve plant health; penicillin_ and streptomycin, for example, are produced by a soil-borne fungus and a soil borne bacterium, respectively.
All nitrogen is not the same
Ultimately, from the plant's perspective anyhow, the role of the soil food web_ is to cycle down nutrients until they become temporarily immobilized in the bodies of bacteria and fungi and then mineralized. The most important of _these nutrients is nitrogen-the basic building block of amino acids and,_ therefore, life. The biomass of fungi and bacteria (that is, the total amount of_ each in the soil) determines, for the most part, the amount of nitrogen that is_ readily available for plant use.
It wasn't until the 1980s that soil scientists could accurately measure the_ amount of bacteria and fungi in soils. Dr. Elaine Ingham at Oregon State University along with others started publishing research that showed the ratio of_ these two organisms in various types of soil. In general, the least disturbed soils_(those that supported old growth timber) had far more fungi than bacteria,_ while disturbed soils (rototilled soil, for example) had far more bacteria than_ fungi. These and later studies show that agricultural soils have a fungal to bacterial biomass (F:B ratio) of 1:1 or less, while forest soils have ten times or more_ fungi than bacteria.
Ingham and some of her graduate students at OSU also noticed a correlation between plants and their preference for soils that were fungally dominated_ versus those that were bacterially dominated or neutral. Since the path from_ bacterial to fungal domination in soils follows the general course of plant succession, it became easy to predict what type of soil particular plants preferred_ by noting where they came from. In general, perennials, trees, and shrubs prefer fungally dominated soils, while annuals, grasses, and vegetables prefer soils_ dominated by bacteria.
One implication of these findings, for the gardener, has to do with the nitrogen in bacteria and fungi. Remember, this is what the soil food web means _to a plant: when these organisms are eaten, some of the nitrogen is retained by_ the eater, but much of it is released as waste in the form of plant-available ammonium (NH3). Depending on the soil environment, this can either remain as_ ammonium or be converted into nitrate (NO3,) by special bacteria. When does_ this conversion occur? When ammonium is released in soils that are dominated by bacteria. This is because such soils generally have an alkaline pH_(thanks to bacterial bioslime), which encourages the nitrogen-fixing bacteria to thrive. The acids produced by fungi, as they begin to dominate, lower the pH_ and greatly reduce the amount of these bacteria. In fungally dominated soils, much of the nitrogen remains in ammonium form.
Ah, here is the rub: chemical fertilizers provide plants with nitrogen, but_ most do so in the form of nitrates (NO3). An understanding of the soil food_ web makes it clear, however, that plants that prefer fungally dominated soils ultimately won't flourish on a diet of nitrates. Knowing this can make a great deal_ of difference in the way you manage your gardens and yard. If you can cause_ either fungi or bacteria to dominate, or provide an equal mix (and you can-_just how is explained in Part 2), then plants can get the kind of nitrogen they prefer, without chemicals, and thrive.
Negative impacts on the soil food web
Chemical fertilizers negatively impact the soil food web by killing off entire_ portions of it. What gardener hasn't seen what table salt does to a slug? Fertilizers are salts; they suck the water out of the bacteria, fungi, protozoa, and_ nematodes in the soil. Since these microbes are at the very foundation of the_ soil food web nutrient system, you have to keep adding fertilizer once you start_ using it regularly. The microbiology is missing and not there to do its job, feeding the plants.
It makes sense that once the bacteria, fungi, nematodes, and protozoa are_ gone, other members of the food web disappear as well. Earthworms, for example, lacking food and irritated by the synthetic nitrates in soluble nitrogen_ fertilizers, move out. Since they are major shredders of organic material, their_ absence is a great loss. Without the activity and diversity of a healthy food web, you not only impact the nutrient system but all the other things a healthy soil_ food web brings. Soil structure deteriorates, watering can become problematic,"_ pathogens and pests establish themselves and, worst of all, gardening becomes_ a lot more work than it needs to be.
If the salt-based chemical fertilizers don't kill portions of the soil food web, rototilling will. This gardening rite of spring breaks up fungal hyphae, decimates worms, and rips and crushes arthropods. It destroys soil structure and_ eventually saps soil of necessary air. Again, this means more work for you in_ the end. Air pollution, pesticides, fungicides, and herbicides, too, kill off important members of the food web community or chase" them away. Any chain_ is only as strong as its weakest link: if there is a gap in the soil food web, the system will break down and stop functioning properly.
Healthy soil food webs benefit you and your plants
Why should a gardener be knowledgeable about how soils and soil food webs_ work? Because then you can manage them so they work for you and your_ plants. By using techniques that employ soil food web science as you garden,_ you can at least reduce and at best eliminate the need for fertilizers, herbicides,_ fungicides, and pesticides (and a lot of accompanying work). You can improve_ degraded soils and return them to usefulness. Soils will retain nutrients in the_ bodies of soil food web organisms instead of letting them leach out to God_ knows where. Your plants will be getting nutrients in the form each particular_ plant wants and needs so they will be less stressed. You will have natural disease prevention, protection, and suppression. Your soils will hold more water.
The organisms in the soil food web will do most of the work of maintaining plant health. Billions of living organisms will be continuously at work_ throughout the year, doing the heavy chores, providing nutrients to plants,_ building defense systems against pests and diseases, loosening soil and increasing drainage, providing necessary pathways for oxygen and carbon dioxide._ You won't have to do these things yourself.
Gardening with the soil food web is easy, but you must get the life back in_ your soils. First, however, you have to know something about the soil in which_ the soil food web operates; second, you need to know what each of the key_ members of the food web community does. Both these concerns are taken up_ in the rest of Part 1.
--
Billy
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wrote:

Wow......I gotta get this book.
I agree with the non-rototilling. I have used the monster when breaking new ground, but have not had it in my beds for several years. I have been loosening the soil in the fall, and spring with a tater fork. I have been wanting to get a broadfork for this, but they are kinda pricey.
A friend of my son is a welder is going to put one together for me this winter.
Great info in the teaser chapter.
Eating a tomato is like eating a miracle, or a marvel, or ......wow. I had no idea about the extent of the wonders going on beneath ground level.
Thanks, Billy. Charlie
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thats good stuff Billy, thanks for sharing it. One resource I found really interesting & helpful was a guide to organic pastoralism. It really started me down a different path. It is free to download http://www.biodynamic.org.nz/guides/intro_ch1.pdf
rob
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Good read. Thanks for the heads up.
--
Billy
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Hi folks,
I am the author of teaming with microbes. I hope you all enjoy it. In fact, if you buy it and really don't like it, contact me and I will refund your money......Just wanted you to know that If you have a first printing edition, there is a mistake on pages 41 & 42....re pH....the higher the pH the more alkaline the soil...the lower the pH, the more acidic. If you have few hydrogen ions, the pH is high.....etc.
Anyhow, this has been corrected in the second printing edition.
If you have questions, or want a speaker etc, you can contact me off list....I do weddings and Bar Mitvahs....anywhere there are gardeners~
Cheers,
Jeff Lowenfels Anchorage, Alaska

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snipped-for-privacy@gardener.com wrote:

Specifically,
1) Page 41, Soil pH, starting with the end of the second line: " If you have relatively few hydrogen ions compared to the rest of what is in solution, the pH is low and the solution is acidic."
This is an error. High concentrations of (H+ or H3O+: hydronium ions) make the solution acidic.
The pH measures the concentration of (H+ or H3O+: hydronium ions) in the solution. 1^E-1 is larger than 1^E-14. The -1 and the -14 are made positive by convention. pH1 is strongly acidic and pH 14 strongly basic. Because pH 14 is so basic, there are very few hydronium ions floating around.
2) Then third line up from the bottom of p. 41: As the concentration of H+ goes up, the pH goes up-the soil is increasingly alkaline. It should read, "As the concentration of H+ goes up, the pH goes down-the soil is increasingly acidic
3) Then first line, first sentence p.42: Adding OH to the solution lowers the pH (that is, soil is increasingly acidic) because it lowers the concentration of H+. It should read, "Adding OH to the solution raises the pH (that is, soil is increasingly basic) because it lowers the concentration of H+."
Other than that snafu on the first edition the rest seems fine. Presently I'm reading a first edition from the library but I plan on buying the second.
--
Billy
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Some comments in line
...snip... quite good stuff on the role of microbes and plants

A good point.
...

Nicely put.
.....

Not necessarily. Many nutrients are bound fairly tightly to colloidal surfaces in clay and humous. OK the microbes have a big role in making humous but they don't make clay.

Once again not necesarily. If you have sand-based soil you spend you life building it up with organic material to stop this happening but with clay-based soil you don't, they hold most nutrients well.
..snip....

What does 'mineralized' mean here? It's not clear to me.
...snip..

I presume they mean NH4+ the soluble ammonium cation (positively charged particle), NH3 is ammonia gas.
Depending on the soil

Here they mean NO3- the soluble nitrate anion (negtively charged particle).
Why am I being picky about these being ions (that is charged)? Because the fact that they are charged is important to understanding how they bind to colloids, which is key to nutrient retention, a point which is overlooked by the author.
When does_ this conversion occur?

All well and good but ignores the fact that the alternative to adding synthetic nitogen compounds (ignoring nitrogen fixing for now) is adding manures or urine. It's true that these don't contain much in the way nitrates from the beast but nitrates are formed naturally in manure heaps. Gunpowder use to be made from potassium nitrate gathered from manure heaps.

Evidence please. The following isn't good enough.

Irrelevant. You don't put salt (sodium chloride) in your soil and the way it kills slugs has little to do with the topic. Remember that salts are a class of chemical substances which are NOT just common salt (sodium chloride) in general, although sodium chloride is in fact a salt.

In excess yes. In excess synthetic fertiliser AND natural ones will both kill your plants in the same way. This does not mean that there are no dissolved salts (as ions) in healthy soil nor does it mean that you should never add such ions to your soil. You do it every time you apply chicken manure or piss on the lemon tree.
...snip...

Agreed. Once your beds are established heavy soil turning either manually or mechanically is harmful rather than helpful.
.snip....
Overall this is not a bad chapter but (unless some details are corrected in later chapters) it is incomplete and in part misleading. The main point that soil is a living community that must be maintained is very valuable.
David
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Your a damn fine skeptic mate. Let me see if I can make another run at this. I'll get back to you soon. Sorry, it's a bit late for me and I'm ever so slightly hammered.
--
Billy
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wrote:

Crap....you aren't gonna break the rule and post whilst hammered, eh?
So much for the entertainment tonite.
Might as well go finish me bottle and watch the blinks.
Funny thing about the blinks, our yard and garden, in particular, are full of them. The chemical-heads yards, that I can see while hanging over the fence, show very few.
I look forward to your's and David's discourse on this.
Charlie
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Wish we had blinks here.
Bonne nuit. Schlaft gut.
--
Billy
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------- I think the nutrients would have a hard-time penetrating the clay. Until it is turned and amended, clay soils cause puddling. My understanding of clay is that it is not colloidal. The charge separation in the molecules that comprise the clay will attach to the hydrophilic (or polar end) of colloidal material. This is how it is used to clear wine and honey of colloidal hazes. This clay (bentonite) is made into a slurry ond then added to the wine. (I'm a bit hazy on how it is done with honey but I'm sure it is essentially the same thing.) It is turned into a slurry to increase its' surface area. The retention area of clay soil would be it's surface and any cracks it develops during the dry season. Clay also hangs on to its' water making the intake of ions more difficult.So it seems that the problem with clay soil is its' resistance to flows of nutrients through them. Eve if there are nutrients in the clay, they must still find their way to the rhizosphere for them to be of use to the plant. -------

------- Here I think the question is hold or block? If the chemical nutrients are blocked at the surface then that is were some other plant will have to use them. If you have amended your soil so that the chem ferts can reach the rhizosphere then, as contended by the authors, it will kill the bacteria and fungi in the soil and consequently the nematodes and protoplasms as well. From there on out, the natural fertility of the soil is dead and you are obliged to renew it by adding more petrochemical fertilizers to feed you plants. ---------

------- I'm with your there. All I know, I found at http://en.wikipedia.org/wiki/Mineralized . I presume it has to do with converting NH4 (organic) to HNO3 (inorganic). --------

-------- Sounds right to me. So we are talking NH3 + H2O <---> NH4 + OH. The equilibrium will still be far to the left. -------

------ Let's get on the same page here. Colloids, in my understanding, (and I presume that I couldn't stop you from correcting me even if I tried) are composed of molecules that have one water soluble end and one that isn't. The colloidal particle has all its' non-water soluble ends together in the interior of the particle and exposes its' water loving end at the surface to its' aqueous solvent or (vice-a-versa). Why is this important to nutrient retention? ------

------- In the soil by nitrogen fixing bacteria (those that can make the conversion from ammonia to nitrate, not N2 to nitrate), hopefully in the rhizosphere where it will be of use to the plant. --------

------You were as hammered as I was, weren't you?? Synthetic nitrogen is a salt, the osmotic pressure it engenders kills the soil flora and fauna. In manure it comes from the break down (de-aminization) of amino acids (NH3, not salt), which in turn nurture the soil flora and fauna. -------

------Look at http://www.biodynamic.org.nz/guides/intro_ch1.pdf that was pointed out to me by a Kiwi, George.com. At the end of the pdf is the bit about fertilizer salts and some references. That's all I know mate. Suspect we'd need a microscope to make the evidence more tangible. ---------

----------- First line below. Fetilizers are salts. They separate into cations and anions, creating osmotic pressure that kills the microbes. -------

-------- Very good point. Chem ferts can be used but we don't know the safe dilution level. Maybe it's just me but I don't trust recommended dosages because, I reason that they want you to use them up quickly and come back for more. Secondly, if you do kill your microbes then you are relaiant on the chem ferts to feed your plants. Now with ammonia, you can smell it and a radical increase in the pH of the soil is apt to kill your plants. So don't apply, if you can smell it. Also it (nitrogen) can be safely added as protein. Microbes won't break it down if products become toxic. -------

----- Right on, right on. ------

It always seems the more we know, the less we know. I was surprised that most of the books that I turned to to get some background on the interaction between plants and soils, had very little information. It was like I was looking for physiology and the books were giving me anatomy.
Thanks for the questions because I think I have a better grasp of the subject now.
Scratch yer Crater,
--
Billy
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Yes if all you have is clay, I was talking about clay as a component of soil, like humus, not pure clay. My place has about 4-6 in of dark brown topsoil over 3-8 ft of yellow plastic clay. If I ever turn up the clay it is unmanageable. The topsoil which is clay-based comes with a component of silt and organic matter to which I add more compost, gypsum (a salt BTW), garden lime and dolomite (salts), chicken litter and horse manure. After a year it holds water and allows infiltration but drains quite well (although I still build up my beds) and it holds nutrients wonderfully.
The gypsum is Calcium Sulphate which is slightly soluble, it helps to break up clay by binding to the surface of very small particles and allowing them to clump, see below on colloids. The dolomite and lime raise the pH (my soil is naturally 5.5, I like it about 6.5 for most things) and supply Calcium and Magnesium ions.
The plastic clay underneath acts like a freaking huge sponge, it means my pasture grows for months after rain as the clay slowly gives up the water it absorbs during rain.

It is. See below.
The charge separation in the molecules

This is a bit confusing, we will get to a better coverage of particle size, charge and colloidal behaviour later.

It does hold water but this does not prevent ion intake.
So it

There is no reason that plant root hairs cannot absorb nutrient directly from clay particles.

I think this is an extreme view, I mainly use manures but will use synthetics in some cases. Used judiciously AND combined with appropriate maintenance of organic matter and soil structure there is no reason for synthetics to be harmful.. Where they ARE harmful is when people think they can use them without attending to the other components. Manures are more foolproof to use without too much thought, provided you don't overdo it when fresh, as they contain organics, microbes etc as well as the raw nutrients.

I think this might be it. http://en.wikipedia.org/wiki/Mineralization_%28soil%29

No in soil it will be far to the right because there is excessive water compared to the ammonia. This is unless the soil is very dry or you have added large amounts of ammonia. This is why the Nitrogen content of fresh poultry manure is fleeting (and why it takes your breath away) because it emits NH3 unless you get it into the soil with lots of other stuff and water where it can be diluted and absorbed.

Colloids are substances that are VERY finely divided, they may or may not have polar bits on the surface. You can have inorganic colloids (eg clay) or organic (humous). The fact that they are composed of very small particles means for a given weight their surface area is huge.
See http://en.wikipedia.org/wiki/Particle_size
Surfaces are where all sorts of interesting chemical and physical changes happen. So colloids can be very active in living and unliving systems. Clay colloids are the sort with charged surfaces (especially negative charges) so they can bind positively charged ions like metals (Calcium2+, sodium+, potassium+ etc) or ammonium NH4+. This is how they hold mineral nutrients. This is one reason that sodised soil (excessive salt, sodium chloride) are infertile because the sodium ions (that plants only need tiny amounts of) displace all the others (eg potassium) that they need lots of.

This isn't right. See http://en.wikipedia.org/wiki/Nitrogen_fixation

No. Jober as a sudge. Manure heaps may not be the best way to describe it, try this. http://en.wikipedia.org/wiki/Potassium_nitrate
Synthetic nitrogen is

No. *Excessive* soluble salts kill cells by damaging them with osmotic pressure. You cannot have living things without soluble salts. This false distinction between synthetic and natural sources of such salts is claptrap. The important thing is the whole regime that use to maintain your soil not whether the chemicals come out of a chook or a steel pressure vessel. This point about NH3 is also misleading. You can add natural NH3 in chook poo (mainly as NH4+) or stuff the synthetic dry gas directly into the soil where it immediately combines with water to give NH4+. Insofar as the NH3 it makes no difference. The chook poo might be preferred for other reasons but not because it is "natural", whatever that means, it's the same freaking molecule.

The biodynamic guys are extremists in this. They firmly believe that there is something magical about "natural" substances. Living and once living things contain some kind of life force in their religion. This, like all religion, is a matter of faith which can neither be proved or disproved. For me I see no need to invoke the supernatural to explain how stuff happens.

Dealt with above.

This safe level stuff is just propaganda. You get the same ions out of synthetics as "naturals" so why should we assume they behave any differently. The problem with synthetics is that it is so much more concenrated it is easier to overdose.
Secondly, if you do kill your microbes then you are

Good thinking! But avoiding excess applies equally well to applying synthetic ammonia as chook poo.
Also it (nitrogen) can

I don't know what you are getting at here. What protein would you add to soil?

There are good books out there on soil chemistry that are aimed at the non technical person whcih are not just shills for chemical companies.
David
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Lord love a duck, mate. This will take some muckin' about to get straight. Score one for you, what I would call an emulsion the ignorant Wikipedia calls a colloidal dispersion. Stupid bastards.

Well, not so much a sponge as a stopper. We call it hardpan. The water can't go anywhere. Also makes it hard for trees to set tap roots and find water, which then require watering.

Not if the soil is amended, such as you have.

I don't see any disagreement here. Clay impedes the flow of water and will attempt to bind with passing charged particles. (Need to get an authority for this.)

So what your saying is that you've created an agricultural pot, the sides and bottom of which is clay and that the nutrients that you put in the pot, stay in the pot because the clay isn't permeable. RIght?
I'm thinking that the salts can't leave either but I'll revisit that later.
One observation though, this is the way we try to keep landfills from contaminating aquifers and how we sequester material from Superfund sites.

Agreed, but no one uses green animal manures on food crops. Now I've offered 2 authors, plus references, that contend will damage soil fertility by killing off the micro-organisms that provide nutrients and soil structure, if used in excess. Can you tell me what a healthy level of chem fert is that doesn't harm soil organisms and provide supporting documentation?

So it takes it back to before de-aminization to the amino acids.

Just a little nit-pick. To the left.
NH3 + H2O <---> NH4 + OH
1.82 x 10^-5 = ([NH4] [OH]) / (NH3)
The ammonia is on its' way out (as a gas) until it is converted to NO3.

I'm still having trouble with your use of the term colloids here, in reference to clay. Clays have stoichiometric formulas colloids (according to stupid head Wikipedia) have continuous and dispersed phases. I'm beginning to think that you are referring to is your mixture of organic material and clay soil as a colloidal despersion or suspension.

Na und?

I said not N2 to nitrate which is what "nitrogen fixing" bacteria do. I'm referring to NH4 ---> NO3.

Interesting, I always thought the way was to burn sea shells, grind them up, add them to water with vegetation, boil, filter, and evaporate.

The authors didn't say that any quantity would kill micro-organisms. That is reflected here somewhere. But with my suspicion that we are already advised by the instructions on the package to use more than we really need (my paranoia, if you will) and the if-a-little-bit-is-good, then-more-must-be-better mentality, serious damage can be done to the soil. I take full responsibility for my claptrap.

OK, OK, I'm no fan of booga booga either. Pick out the watermelon seeds and enjoy. There is a lot of good science in that pdf. The only time they lost me was with the "bio-dynamic" calendar and the adding paramagnetic rock to the soils. Belief is not required. Again, did you see the excerpts from "Omnivore's Dilemma"?

And I think that is what we are talking about. Excess. If you give the micro-organisms the organic nutrients they need they will convert them into the materials needed to create a web of life that supports the soil and your plants. Where a large and diverse population of micro-organisms can protect against non-benevolent micro-organisms. I realize that you don't just use chem ferts but none of them support the diverse population of organisms that make your soil fertile. Otherwise you may as well go hydroponic.
We aren't trying to make a goose from Toulouse here, where you "cram" it full of nutrient so that you can eat its' liver.
The ideal is to create a biome. Ideally with crop rotation and green (plant) manures we can create sustainable (or nearly sustainable) agriculture.

Did you see the excerpts from "Omnivore's Dilemma", footnoted with work from the University of California at Davis stating that nitrogen from chem ferts concentrated in leaves and attracted insects?

Dog hair for one and then there is the protein that make up the micro-organisms.

I thought that was my line? Anyway, the books I've seen so far tell about soil composition and how to correct any faults. What I don't see very often are books explaining the microbiology and their impact on farming and gardening.

Got the second longest day of the year going on here. I'd better get out and get me some. Have a Cooper's stout for me.
--
Billy
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This is not what I observe. The tree roots go right into it and once established become much more drought proof. I also observe the sponge behavour as do my neighbours who have been farming here for generations.

you
No. My amended gardens are all on top of the solid clay, I try to never bring it to the surface. The reason the amended soils hold nutrients so we is the colloids from the humus and the clay mixed into them.

Agreed.
David
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All right David,
I think you are due the following:
http://www.youtube.com/watch?v.Mkth8FWno&mode=related&search=
.
I wanted clean this up a bit as our discussion was getting spread out and I'd like to keep it coherent.
My main contention is that chemical fertilizers may be used for crops but they don't do anything for the soil ecology and, at worst, will damage the soil, if used exclusively in place of organic fertilizers, or if they are used in too high a concentration. A concentration of which we are ignorant. We don't know what it is. Whereas, organically fed soil, will support the thousands of different bacteria, fungi, protoplast, nematodes, and earthworms that form the base of the soil biome. These in a symbiotic relationship with the plants nurture each other from their own niches. When the crops grow, they provide nutrient for the micro-organisma. When they die, they provide more nutrient. When the bacteria and fungi form alliance with the plants, they provide nutrients for the plants. When the micro-organism dies, it provides more nutrient for the plants. A win-win situation. Working together, they create an inter-active ecology in which ever larger species can exist.
Perhaps there is a role for chem ferts, but I would have to think that it would be limited.
Now, what I was woefully ignorant of was soil composition (30%-50% sand, 30%-50% silt, 20%-30% clay, and 5%-10% organic material. If this is homogenized in you garden, you will have excellent soil. I was unaware of the importance of clay and humus in binding nutrients, thanks for the heads-up.
You seem to be proud of what you've accomplished with your growing beds. Could you tell me your approach and maybe clear up my confusion to your use of the word colloidal? Sand, silt, and clay represent a gradation of inorganic material. Since the inorganic fraction is the largest fraction of the garden, it must represent the continuous phase, whereas the organic must be the dispersed phase.
--
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