Sonntag, 20. Januar 2013
Ingham on Compost & Bokashi
An interesting discussion about Aerobic, Anaerobic, Fermentation, Putrefication in composting
with Elaine Ingham (the only one I know of, who is able to look at the soil in a way the Francés did)
in a network of Steve Diver (formerly ATTRA) http://www.ibiblio.org
soil amendments from composting v fermentation
Elaine Ingham, 15 May 2004
Anaerobic metabolism includes several metabolic pathways, and the different end products from the different pathways need to be differentiated, because some pathways end up with plant toxic materials being produced, while others do not.
However, all anaerobic processes result in significantly acidic organic acids being produced, which may or may not be a problem for your plants. Depends on the plants being grown, right? What pH do they need?
Those organisms that produce mainly lactic and proprionic acid as the main metabolic end products and do not produce hydrogen sulfide or ammonia. They can make phosphine gas, however, which means your PO4 may be out-gassing. So, a little sour smell to the process, some loss pf PO4, somewhat low pH metabolites produced. This may not lower pH in hte pile much, since the acids mix with the organic matter that have a higher pH.
Most people use the term "fermentative metabolism" for these metabolic processes. Wine and beer production use particular species that perform this type of anaerobic metabolism. Can we call this kind of anaerobic metabolism fermentation, please.
As opposed to putrefaction. Putrefactive processes make the really bad smells, because hydrogen sulfide production is a putrefactive process. Ammonia is also produced, along with phosphine gas, and a host of really bad smelling organic acids, from vinegar (acetic acid) to vomit (valeric acid) to putrescine. Alcohol is produced by the bacteria in significant quantities, high enough concentration to kill plant roots. This can be a real problem if you use mulch that has suffered this kind of anaerobic metabolism.
Note that I do not call this compost, becasue it is not compost.
Putrefactive anaerobic conditions are what you want to avoid. If the compost pile becomes anaerobic, you need to turn it or dilute the food resources to slow the bacteria and fungi down. Bacteria and fungi can grow so fast that they use up most of the oxygen in the pile. They use up the oxygen because they are growing on the foods in the pile so fast. As they grow, they generate heat.
Thus, if you are careful to never let the pile go anaerobic, heat will tell you when to turn. But if the pile goes anaerobic, then heat is not related to anything positive anymore.
Composting is by definition an AEROBIC process. Worm compost has to be aerobic, because the worms require aerobic levels of oxygen. But the lower layers in a worm compost can go anaerobic. If that happens, the worms will no longer go down deep into the pile.
And it is the SUM of the pile that needs to be considered. Pockets of the organic matter can have low oxygen, where the anaerobic metabolites will move into the aerobic areas, but as long as most of the pile is aerobic, the anaerobic metabolites get consumed by the aerobic organisms, and just help increase diversity in the pile.
What's the right balance to achieve a pile that is enough aerobic? That's what the microbiology of compost course is about that I teach. A couple students are involved right now in replicating the process so we have the solid, scientifically sound results to present.
"aerobic" bokashi ?
Elaine Ingham, 4 Sep 2005 21:41:48
When you add in all the materials typically added in bokashi (which were mentioned in the original post), and do not turn or mix except once a week, the resulting material will go anaerobic, because of the rapid growth of the microbes in the organic food resources added.
It is not possible that the mix described could stay aerobic, unless the material was put in a refrigerator, or kept at very low temperatures to reduce microbial growth.
Bokashi is produced by an anaerobic process.
Protozoa, the beneficial fungi and the beneficial nematodes will be lost as soon as the material becomes anaerobic.
Does that mean there is no benefit of using bokashi, or ferments, or anaerobic materials as part of a soil program?
Please, I have never said that there was no benefit.
But, if you say there is a benefit, then explain exactly what benefit there is, and how that can be reliably repeated time after time.
Lactobacillus, proprionic acid-producing bacteria and other facultative anaerobic bacteria, and some actinobacteria and yeasts typically found in bokashi can do some very interesting things.
But they cannot do all the things a full foodweb set of organisms will do for plants.
Don't ask bokashi to do everything and don't make claims that these organisms can do all the things aerobic soil organisms can do.
Can bokashi organisms start moving soil in the right direction?
Sure they can, especially if they start suppressing disease organisms, and begin the process of building soil structure, and leaving behind some organic matter.
But they cannot give all the things a good healthy set of aerobic organisms, the full foodweb of organisms, give to a plant.
facultative - mandatory
Heide, heidehermary, 9/4/2005 8:52:43
can you tell us how this bokashi worked for the farmers?
Also where did you obtain the mature bokashi to put into the mix, or can it be substituted with EM inoculant?
I'm also curious about the reason for adding the charcoal.
To summarise the story, if you’ve worked with (aerobic) bokashi, I would really appreciate to get some feedback.
I’ll tell a bit of the background story and then explain my doubts.
The recipe we used to prepare bokashi was adapted from an IICA publication (1) in Spanish. The components used were: 100 kg of soil, 100 kg of fresh cow manure, 100 kg of rice bran, 50 kg of ground charcoal, 20 kg of rice hull, 5 kg of ashes, 5 kg of mature bokashi, 1 kg of molasses, 250 g of yeast and water. All components were mixed homogeneously while water was added to the mixture. The heaps were turned twice and then once a day until the temperature stabilized. The composts were considered ready to use after 20 or 21 days.
It goes without saying that we tried to use as much as possible what was locally available and at the lowest possible cost. It would be completely out of out of touch with the local reality to use a commercial inoculant there.
The project is now over and I’m trying to figure out what happens in bokashi production. As far as I’ve seen, there’s not much about (aerobic) bokashi in scientific publications while there’s quite a lot about it on the net but almost everything is about what is sold on the market such as EM inoculants and the like.
I’ve seen that, some sources refer to ‘bokashi’ as a biofermented fertilizer. As far as I remember from chemistry courses a long way back, fermentation is an anaerobic process. Or can it be aerobic as well? The production of the compost itself is an aerobic process so maybe bokashi is called ‘fermented organic matter’ because Japanese farmers, who first ‘discovered’ it, made first a fermented anaerobic inoculant which was then added to the substrate mixture? Have you got a better clue on why bokashi is called a fermented organic fertilizer?
Microorganisms exist everywhere.
In this case I reckon the soil, the manure, mature bokashi and the yeast will mainly provide the microorganisms which will mineralize N from the composted material and also enhance availability of other plant nutrients.
The molasses here will provide the ‘energy’ or feedstock for microorganisms boosting their growth.
Looking back, what we did was to get the microorganisms we wanted to do the job in contact with a substrate which we wanted to be decomposed (mineralized) at the same time that we provided something that made the microorganisms multiply much faster.
From what I’ve experienced, there is indeed no need to buy a special inoculant.
Keine Pflanze kann Bokashi direkt konsumieren, der PH ist zu niedrig und die fermentierten organischen Materialien sind noch keine unmittelbare Pflanzennahrung (mit Ausnahmen - wie immer).
Diese fermentierten Materialien sind ein Zwischenprodukt, das lange Zeit in diesem anaeroben Zustand gehalten werden kann. Vielleicht eine Art vorverdaute und haltbar gemachte Pflanzennahrung.
Soll es den Pflanzen zur Nahrung diesen, so muß sie von aeroben Mikroorganismen weiterverarbeitet und verändert werden und zwar von denen, die schon im Boden vorhanden sind und die Humus, die Pflanzennahrung aufbauen können (Das Bokashi muß "vererdet" werden wie die "Bokashir"er sagen).
Grundsätzlich ist die Fermentation ein Umweg zum Humus (Die Firme sonnenerde.at hat das auch festgestellt).
Welche Vor- und Nachteile dieser Umweg hat, bleibt nüchtern zu untersuchen.
Auf jeden Fall ersetzt er nicht den "normalen" aerobischen Weg, die organischen Materialen über den Kompost zum Humus umzuwandeln - denn das hat die Natur als den unter den bisherigen Bedingungen besten Weg entwickelt.
Vielleicht ist er ein Pufferspeicher, der seine Nähstoffe zeitlich versetzt langsam zu Verfügung stellen kann. Ein Sonderfall, den der Mensch herausgefunden und sich zunutze machen versucht, der aber nur funktioniert, wenn der Normalfall vorherrscht
Wobei auch im normalen Komposthaufen nicht nur rein aerobe Zustände herrschen, es gibt auch immer wieder anaerobe kleinere oder größere Regionen, deren Effekt, Sinn und Zweck noch einer gesonderten Untersuchung bedarf.
Endlich mal eine bodenständige Bewertung (im wahrsten Sinne des Wortes) aus langjähriger Praxis der Kompostierung und tiefer sachlicher Kenntnis der mikrobiologichen und chemischen Vorgänge.