[Terrapreta] Soils, sugars and nutrient elements-response

[Kevin Chisholm]

Dear Janice

Janice Thies wrote:
> Dear Kevin,
> 
> I can address some of these questions for you and clarify a few 
> misconceptions.
> 
> First, plants do not gain their energy from the soil.  They 
> photosynthesize, meaning they use energy from the sun to make reduced 
> carbon compounds (such as sugars) necessary for growth, development, 
> reproduction and metabolism from carbon dioxide.  This does not mean 
> that they do not respire, they do.  They use the organic C compounds 
> (sugars) they produce via photosynthesis to generate cellular energy for 
> other metabolic processes.  So, where you comment that the plants are 
> getting energy by feeding sugar to the soil - this is not the case at all.

Sorry... this was sloppiness on my part... Dr. Karve's sugar method is 
clearly intended to "feed the soil", rather than feeding the plant.
> 
> Instead, what is likely happening is that soil heterotrophic organisms 
> (decomposers) are using the sugars themselves for energy.  Where there 
> is abundant energy (carbon compounds, such as sugars) and abundant 
> mineral nutrients (such as N, P, K, Mg, S, etc), the mineral nutrient 
> elements will increase in concentration in the soil solution as they are 
> in excess of the cellular needs of the microbes.  Hence, more of these 
> nutrients are available for plant uptake (because they do take these up 
> from the soil solution). Where there is abundant energy and mineral 
> nutrient elements are scarce, then they will likely be "immobilized" in 
> microbial biomass and NOT available to plants.  This is the explanation 
> for the 'robbing N from plants' part of your question.

OK.
> 
> On in place composting, you need to be careful of a few things.  The pH 
> of the materials incoming, their C:N ratio, salt concentrations and how 
> much of a good thing there is come to mind immediately. 

With "natural" materials, such as agricultural waste, food waste, etc, 
is there any concern for pH? What are some examples of situations where 
pH would be a significant concern? When you refer to "salt", do you mean 
the equivalent to ocean spray, or perhaps some other salt source?

  One hallmark of
> composting is the thermogenic stage, where the pile heats up.  This can 
> help begin the decomposition of more recalcitrant materials, but can - 
> if happening in place - burn your plants literally. 

I can see heating as a concern, when teh compost bed is rich, well 
balanced with C/N, and well aerated. Is overheating a problem with 
composting in place, where aeration is likely to be inferior, and teh 
rate oc composting slower?

  If urea is present
> in high amounts, this can cause another kind of leaf 'burning' to take 
> place.  If the pH of the material is too high, N may be lost an ammonia 
> to the atmosphere, if the pH is too low, plant roots will be very 
> unhappy. 

If manures and greens are used as the source of Nitrogen, rather than 
synthetic Nitrogen sources, are tehse concerns still valid?

  If the C content is very high, then N will be immobilized, if
> it is very low, then it is likely to be very actively degraded and 
> localized heating can be expected.  Salts can also be a problem if the 
> materials are not mixed to dilute them with the surface soil or other 
> organic materials that are low in salt content.  So, know your materials 
> is the best bet.  Understand how they will behave as they decompose in 
> place and be sure that you do not inadvertently harm the system while 
> trying to preserve the nutrient content to feed the soil, rather than be 
> lost to the atmosphere.

OK...
> 
Del...


>> On the other hand, composting "in place" does end up with more "in 
>> place energy availability". The first question is: Is this potential 
>> energy available to the plant, or does it simply get consumed by the 
>> "in-place
>> composting bacteria", with no direct benefit to the plant? 

>the latter
>>
>> The next question is: It there any way to prevent the "in-place 
>> composting process" from temporarily depleting the Nitrogen that would 
>> otherwise have been available for plant growth? 

> yes, by keeping the 
>> C:N ratio overall not too much higher than 20:1, which is the 
>> theoretical tipping point between N immobilization and N mineralization.
>>
OK!! This would seem to be why Dr. Karve's "sugar feed" works... a 
relatively small anount of relatively available carbohydrate stimulates 
the soil bacteria, and there is not enough to tie up nutrients.

>> One obvious solution to the Nitrogen Availability problem might be to 
>> ensure the raw materials had adequate Nitrogen to permit "self 
>> composting" ingredients to compost in-place, without the need for 
>> temporarily robbing Nitrogen from the plant.  Indeed  However, all 
>> that this might accomplish would be a "self fueled fire". The 
>> ingredients would have no need to interact with the Soil, and rob its 
>> nitrogen. 

> Not sure what you mean here
>>
Dr. Karve suggests there is a significant benefit to "composting in 
place", in contrast to composting the feeds externally, and adding the 
compost. If there was a "perfect mixture of materials for composting, 
there should be no addition to, or draw from, the soil during the 
composting process. What I am missing is an insight into why composting 
in place is an advantage.

>> On the other hand, your "Sugar Fertilizer" procedure seems to work 
>> wonderfully, and no Nitrogen is added to the Soil... only energy for 
>> the plants.  

> This is not energy for the plants as explained above
>>
Poor explanation on my part... what I meant to suggest was that Dr. 
Karve's sugar process adds a very small amount of carbohydrate, not 
enough to tie up sufficient Nitrogen to stress teh plants.

>> Is it perhaps a case of "too much of a good thing is a bad thing?" One 
>> can see that too much cellulostic plant material with a high C/N ratio 
>> added to the soil could possibly deplete N from plants, but if a smaller
>> amount was added, there might not be enough cellulose to deplete 
>> existing soil N to retard plant growth over the short term. 

> Indeed
>>
>> So we seem to get back to the first question: Could you please explain 
>> how the release of energy from "in-place composting" is more 
>> beneficial to the "Soil Food Web" than would be the addition of the 
>> same material
>> that was composted externally? 

> The answer lies in doing 'in place 
> composting' correctly, aiming to not lose your N (and S) to the 
> atmosphere, but keeping it in organic forms, such as living microbial 
> biomass that is recycled on a short time scale.
> 
> Hope this helps.
> 
I am still missing something. I still cannot see why composting "in 
place" would offer any advantage over external composting, assuming 
there was a good mix of ingredients to be composted.
> Janice
>
Thanks again!

Kevin

> 
>> Thanks!!
>>
>> Kevin Chisholm
>>
>> adkarve wrote:
>> > Dear Juergen,
>> > Do not apply compost to the soil.  On the one hand, agronomists tell 
>> us to
>> > apply organic matter to the soil in order to feed  the soil 
>> micro-organisms,
>> > but on the other hand, they ask us to compost the biomass before 
>> applying it
>> > to the soil. The nutritional value of the biomass is lost in the 
>> process of
>> > composting. Also, while recommending the dose of compost to be applied,
>> > agronomists calculate it according to the N.P and K content of the 
>> compost
>> > and not according to the nutritional calories in the compost. We 
>> found in
>> > our experiments that non-composted green leaves, applied at the rate 
>> of 125
>> > kg per ha, once every 2 to 3 months, gives as high yield from crops as
>> > application of recommended doses of chemical fertilizers.  Even in 
>> the case
>> > of dung, we found that relatively small quantities of dung are highly
>> > effective, if the dung is applied in the raw and non-composted 
>> form.  Dung
>> > consists partly of lignin (which can be digested neither by herbivorous
>> > animals nor by the anaerobic bacteria in their guts) and partly of a 
>> large
>> > number of bacteria. Both the lignin and the dung bacteria serve as 
>> food for
>> > the soil bacteria. By composting dung, we unnecessarily rob the soil
>> > micro-organisms of nutrition.
>> > Yours
>> > A.D.Karve
>> >
>> > ----- Original Message -----
>> > From: Juergen Botz <jurgen at botz.org>
>> > To: <terrapreta at bioenergylists.org>
>> > Sent: Wednesday, April 18, 2007 5:45 PM
>> > Subject: [Terrapreta] Greetings
>> >
>> >
>> >> Hello, all.  I just joined the list, glad to see it so lively!
>> >>
>> >> To introduce myself... about a year ago I acquired a small farm
>> >> in coastal Bahia, Brazil.
>> >>
>> >> The land is 2/3 secondary growth Atlantic rain forest, the other
>> >> 1/3 is partially planted with coconut palms and pineapple, plus
>> >> various fruits and plenty of manioca.  Unplanted areas that
>> >> aren't forest are heavily overgrown with dense brush.  The
>> >> subsoil is nutrient-poor loam, often highly compacted.  In most
>> >> spots there's a layer of anywhere from an inch to a foot that
>> >> has a significant amount of organic matter, and yes, quite a bit
>> >> of charcoal.
>> >>
>> >> The charcoal doesn't seem to have been deliberately incorporated...
>> >> rather, the area has been cleared by fire a couple of times in
>> >> the past and because of the high humidity here that leaves a
>> >> lot of charred matter.
>> >>
>> >> I am experimenting with various natural farming and permaculture
>> >> techniques here, and my main goal right now is to get the soil
>> >> in better shape.  That means breaking up the compacted subsoil,
>> >> adding organic matter, adding more charcoal to stabilize it and
>> >> reduce future compaction, planting various leguminous trees and
>> >> ground covers, and of course building up a layer of humus.
>> >>
>> >> I have a source of humus and wood for charcoal in the forest.
>> >> I've also been making large quantities of compost from a mixture
>> >> of wood- chips, manure, and seaweeds raked up at the beach.  I'm
>> >> thinking of adding charcoal to this mix right from the start of
>> >> composting.
>> >>
>> >> One of the things that led me to this list was that I was
>> >> scouring the Net for info on small-scale charcoal production.
>> >> I found a bunch, and I found this list.  I think I'll be trying
>> >> some pit-kiln variation shortly, and in the longer run I may
>> >> build something like the adam retort.
>> >>
>> >> :j
>> >>
>> >>
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>> >> 
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>> >
>> >
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>> > 
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>> >
>> >
>>
>>
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> 
> *****************************************************************
> Janice E. Thies
> Assoc. Professor of Soil Biology
> Director of Graduate Studies
> 719 Bradfield Hall
> Dept. of Crop and Soil Sciences
> Cornell University
> Ithaca, NY  14853
> 
> phone 607-255-5099
> fax    607-255-8615