zondag 8 mei 2016

The method Krantz.

On this blog we often refer to the method Krantz, which basically has been a method to preserve (and finally compost) stable manure. We took the basic idea of this method and applied it to the composting of wild grasses and herbs.

For this we used the research report of microbiologist Dr. Ir. F.C. Gerretsen called 'Soil bacteriology at the service of agriculture and horticulture', which was published in the Netherlands in 1939 by the Department of Economic Affairs. At that time dr. Gerretsen was director of the microbiology department of the state agricultural research station in Groningen.
When Hendrik had a talk with Dr. Gerretsen in 1985 he met an embittered man. A man who had found himself disregarded and maligned. And he did not want to respond to our questions.
This well describes the condition in which microbiologists were in those days. Gerretsen was one of those researchers who had dedicated his live finding the truth behind things. His life's work had been ignored and replaced with the then prevailing economic standard.

The agricultural area in the Netherlands had been parceled out. Much was expected of new large scale farms, they where highly spoken of and the use of fertilizers and pesticides should raise agriculture to a higher level. At the European policy level agricultural subsidies were the engine of this new development. Every 'well thinking' person should support the new 'progressive' policies. There was no place for the microbiology of the soil in this environment, which was to be totally replaced by fertilization calculations and yields per hectare.
And just at that moment we were occupied with organic farming and the composting of grasses of natural areas and roadsides; on the basis of the microbiological knowledge, with which we became familiar due to Gerretsen's report. Well..., pigheaded?
No actually not. We were just interested. We were looking for a good solution to compost wild grasses and herbs. And found a beginning of a solution in the so-called 'cold manure preparation' and also in the Krantz method, by means of Gerretsen. At that time old knowledge was new knowledge for us. We had no prejudices. Our interests were not more specific than those for the construction of an effective composting setup.

Back to 1939.

The dunghill. A mess. A mountain of garbage where all waste from the farm landed. With rain all substances washed out, in nice weather the whole thing started to stink. This was the situation on many farms. Fore the preparation of manure there was hardly any attention. Partly due to the social circumstances which where no good, thus to a lack of knowledge and attention.
People like Gerretsen saw it as their duty to provide information, based on a thorough investigation, given his publications. He was a scientist, not a politician.

Gerretsen says it neatly in the first line under the heading 'Manure Preservation': "In many ways one has been trying to avoid the losses occurring while preparing manure."

It is remarkable to note that a study initially focused on maintaining nitrogen in the manure, lead us to the composting of wild grasses, to which we attach no value at all to the preservation of nitrogen. Our objective is focused on the preservation of the organic substance. And yet, the processes of the retention of the organic matter and the conversion into humus is the same, as those to retain nitrogen in the manure.
All this is connected to the binding and capture of ammonia in humus. That actual is nitrogen (nitrate or protein) conversed into humus.
Read also our post: 'Microbiology for dummies.' About what happens during composting.

Gerretsen says about a good dung conservation result:
"The organic substance must be, as complete as possible, transformed into humus-like substances and in any case the easy decomposable ingredients, cellulose, hemicellulose, etc. must have been disappeared for the most part. Both the dark brown color, as the fact that the straw in this case, has lost its strength and is easy to pull apart, may serve here (...) as a guide."

And this is what we have been experiencing our selves. Once our grass compost leaves the big bag we can pull it apart easily. We stab the material loose and stack it light and airily to let it ripen. It crumbles and falls further apart naturally. After several weeks (depending on when we need it) the compost is oxidized (which means it has become accustomed to the open air) and we can use it. The activity of this compost is further increased by sieving it (which in fact, means aeration) and bringing it into contact with soil and/or old used compost.

Under the heading 'The microbiology of manure preparation' we read about fresh stable manure:
"As the manure is looser stacked and the air could accede more, the losses become greater. The carbon compounds eventually escape as carbon dioxide or methane: According Löhnis, during ripening, from one m3 manure would occur 46 kg of CO2 and 16.9 kg of CH4, also about 47 m3 of gas would be formed. By other researchers, indeed, amounts of 10-100 m3 of gas are measured, volatilized from one m3 of manure."
And then we read about the dunghill:
"The huge losses of organic matter and nitrogen are largely caused by the excessively broad entry of air into the dunghill. This has led, to make structural changes in addition to other more biological transformations."

Then about the so-called 'cold manure preparation', to which is referred as one of the improvements:
"It is worth mentioning the in Germany recommended, so-called "Württembergische Dunglege", which consists of several compartments, which are successively filled and allow for a complete closure of the manure. (...) Also, the manure is stamped down immediately; As a result the air entry from the beginning has been hampered, conversions proceed anaerobic, more slowly and with significantly less loss of organic matter. In order to foster a good conversion, we must also pay attention to a sufficiently moist in the manure..."

Strictly speaking, the reasoning, which is used here with regard to an anaerobic manure processing, is not quite correct. Rightly, however, is the note that the air ingress is hampered. Beyond this, this process does not go. In our post 'Rich in oxygen and oxygen-poor.' we write some more about this subject.

And about 'noble manure' Gerretsen sais:
"Around 1924 a method of manure processing was introduced by the German agricultural H. Krantz, which do justice to various microbiological requirements, which set standards for a proper manure preparation. The principle on which this method is based, is to ferment the manure with a significant air accession, in a short time, and then to inhibit the conversion as much as possible through stamping down the manure considerably. In this way one achieves a fast conversion of the readily to break down C compounds. Also, the evaporation of ammonia is reduced to a minimum. (...) Since the nitrifying bacteria already die around 45ºC, the noble manure is free of these bacteria. This has the advantage that thereby nitrogen losses can not occur by denitrification formed in the nitrite or nitrate in the manure. The advantage of this partial sterilization, paired with a good air seal, once the manure is ripe, no further conversions take place. The value of the manure remains unchanged for months, in contrast with ordinary farmyard manure, in which the microbiological degradation continues and the quantity of which, as well as the quality deteriorates when it is stored for a longer period."

What is referred here to the 'preservation' of manure we tend to call 'composting'. Everything indicates that this manure is composted. And basically, we consider it as such.

Obviously a pile grass or hay includes no excrements of animals. But the largest component of manure is this excrement. However, the same processes take place in our composting of wild grasses.
By adding a percentage of animal droppings to wild grasses we can easily copy the process of the preservation of manure (manure composting). The same bacteria are active here. And the same criteria for air entry and C/N ratio apply here also.
In our post 'Microbiology for dummies' Hendrik already was referring to the difference in C/N between hay from wild grasses (C/N 19/1) and cereal straw (C/N 69/1). Because in wild grasses we see more nitrate, we can do the same work with a lower amount of manure (animal droppings), to prevent the process turning acid. With straw only this will be harder. This straw needs more manure.

The result of all this is that we do not primarily add the nitrogen (in the form of manure) to our raw material grass, but we use the total pool of bacterium from the manure to start the composting and control the process further.
A social side effect of this is that in any area where there is only a little manure, it can be possible to compost wild plants, herbs and grasses. Also here, self-produced compost can improve the topsoil. Fertilizers in whatever form need not be supplied or purchased. It is quite possible to come to a good farming with locally available resources!
At least technically.



April 2015.

The method - Evaluating.

On this blog we share our experiences with the composting of grasses and herbs.

The source of our knowledge lies in the microbiology, the bacteriology of the soil. Specifically in two old methodes for the composting of stable manure.
The first method, the 'Würtenbergsche Dunglege' is called 'cold manure preparation', another method dating from about 1922, was developed by the German agricultural engineer Dr. H. Krantz, producing the so called 'noble manure'.
In both methods the composting process starts with an aerobic bacterial activity, after which, in a second phase, an oxygen-deficient bacterial activity is forced.
With his methodes we gain good results in preserving the available organic matter in grasses and herbs. We make a good active compost, where the organic material is preserved and is enshrined in humus.

The common, well spread, opinion is to aerate materials over and over again when the temperature rises during the composting process. With this aerating lots of organic matter vanishes into CO2, because of the decomposition of organic matter in ammonia due to oxygen. This is unfortunate, because we need the organic material to generate sufficient soil activity (in humus). It is available, so why not preserve it.

Thus we use manure as a compost starter and as a (absolutely necessary) bacteria source that prevents the process going acid, lactic acid or butyric acid. Therefore we soak fresh manure in water and immerse the materials with this manure-water (grafting fluid) before composting. Then we let it all drip and store the immersed materials later for the actual composting, the heating.

In the initial phase of the decomposition sufficient oxygen is required, to start a normal aerobic bacterial action. The temperature rises to 50-70ºC. When we then press the materials with a heavy weight, the materials run out of oxygen and the process turns into a oxygen-poor bacterial action, but without going acid, due to the bacteria in the manure. The temperature drops.
Depending on weather conditions and outside temperature, it takes about 3 months for the materials to decompose. Finally the temperature of the compost pile has droped to about 15-5ºC.

After this process the compost may be aerated so that it can oxidize and 'ripen'. Oxygen enters again and brings back all the necessary processes in motion. The better the compost is aerated at this stage, the faster it will be ready for use. And meanwhile heating remains off, because we passed that stage, the preconditions are not present anymore.

For more details, read:
'About composting grasses. How I do it.'
'This hay is great stuff for composting.'
'Why immerse materials before composting?'
'The great immersion barrel show.'



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