vrijdag 16 december 2016

Like cogwheels.

About the production process.

In our post 'Principles and some food for techies' we made some suggestions for the set up of a small to large composting place or plant. Here one important thing comes up several times and is crucial. All the things you do, within the process, need to connect to one another... 'like cogwheels'.

Some points of attention:


It must be possible to process the delivery of materials almost immediately, to prevent the hay to overheat and burn. Humid materials will scald and burn during a long term storage. And sometimes the supply (of hay) is delivered while it is moist.
We ourselves can store our hay, with confidence, and keep it for several months, because it is guaranteed to be dry when it is mowed. This in itself is typical of this region of Portugal. Although we cover it during the few periodes of rain, in the summer.


Once taken into production the volume of the grafted hay reduces. This is partly due to pressing it down, but also by making it moist. After this first stage in the process, the reduction will only be more, due to the heating and fermentation. From the starting material often about 1/10 part in volume is left. This affects the capacity of the processing at different stages.

Our set up:
1 Immersion barril, 300 liters.
2 drip barrils, along 400 liters.
    The content of 1 immersion barril fits into 1 drip barril of 200 liters.
3 storage barrils along 900 liters.
    The contents of 2 drip barrils fit into 1 storage barril of 300 liters.
    With which the content of 2 immersion barrils is reduced to 300 liters.
1 big bag 900 liters.
    The content of 2 drip barrils plus 3 storage barrils fit into 1 big bag.
    With which the content of 1,300 liters in reduced to about 900 liters.

During the scalding and fermentation (in the big bag) the volume reduces to about 250 liters. During ripening and aerating the volume will increase, after which it decreases again during use in the garden, with which we reckon the volume to be about 250 liters (for safety's sake).

So, with the 2400 liters of starting material, we gain about 250 liters of product.

14, or 15 pack of hay at a time?

Example: Hendrik uses one immersion barril to graft the hay. Herein go 14 to 15 packets of hay. After 8 times grafting, dripping and gathering, the hay goes into the big bag. Added together, this means that 8 x 14 packets, or 8 x 15 packets of hay where grafted... so (in the latter case) at the end of this cycle he has 8 more packets to stack into the big bag. Sometimes those 8 extra packets do not fit into the bag... so they must wait for another cycle of 8 times grafting and keeping. And it may be that these packages have long been heated up before they go into the big bag, with which the process will be delayed. This in itself is not a drama, but it is more complicated because it affects the following cycle. A simple solution is to stack the big bag extra high.

Wrapped big bags.

Hay is a starting material in which, ideally, a lot of air is present. (This in contrast to kitchen and garden waste, which is sticking together and is far more humid.) This in itself makes the aeration of hay during the composting completely unnecessary and counterproductive. Especially wind plays a negative role in the composting of hay. Wind blows everything dry and requires good protection during the composting process. Composting grasses and herbs (hay) will benefit from the exclusion of air and especially from wind.


If we wanted to change our composting, or maybe scaling up, it would have implications for the ability of all means, and parts of the process. Everything we do here is dictated by daily circumstances. The drought, the heat and winds have made the process as it is now. And also the social condition and our place in this affects the choices we make. Thus everyone will make the choice that is best and ultimately works well.

We are curious about similar projects elsewhere, in other circumstances, or on a different scale. Send us your experiences :) compostfarming.tellus at gmail.com



In April all is green...

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