Hot Compost

We had a lot of vegetable scraps left over after feeding people for a week during the Earthbag workshop, way too much for the chickens (5) or the worms to possibly consume. Mission Decompose was the answer aka: Time To Make Compost!
We planned to make a large pile of hot compost, which requires a bit more work than the average “leave it in a pile compost”, but will break down quickly and reach a hot enough temperature to kill any seeds. We had some nitrogen rich veges and Nick grabbed some pure horse manure (manure without wood shavings) on his way back from town to add into the mix as well.
All that was needed was some more green nitrogen rich leaves such as herbs, comfrey and nettles to act as our compost activators and also a lot of carbon rich material.
While Bel sourced our green goodness, Kade, Amelie and I attacked the purple top armed with a rice knife and scythe. Once we had the purple top we cut it with the chaff cutter to create quickly digestible material to add to our compost.

The following is a list of all the “ingredients” in our compost recipe:

100 Litres Oaten Hay (1 Bales)

100 L Lucerne Hay (1 Bale)

450 L Purple Top chaff

90 L Pure Horse Manure

45 L Food Scraps

50 L Green Waste / Activators

1 L Rock Dust (for Minerals)

40 L Old compost (innoculates the new pile with beneficial bacteria/fungi)

First we made a cage to contain the pile, approximately 1.5m in diameter. We started with a layer of carbon about 20cm deep, sprayed it well with water then added a thin layer of vege scraps, followed by a thin layer of manure moistened with water and repeated this process until we ran out of material. In between the layers we added rock dust and the compost activators. We  turned the compost every three days to keep the aerobic bacteria at a healthy high number and to encourage a faster break down rate.
To get a better understanding of what is happening and to learn how to improve future composting we have been documenting the entire process by taking temperature readings morning and night and noting when we turn the compost. The compost should reach between 55 and 65 degrees Celcius in order to kill the seeds so that we will not get weeds germinating in the garden. Any temperature higher and that will start to damage the micro organisms and fungi.

30 days on, and we have since incorporated this compost mix into a new garlic bed, the kicthen garden beds. Ultimately the size of the pile will dictate the rate of decomposition. A pile ready to use will drop in temperature and have no odour – just a nice cool soil smell. It will look dark and crumble in your hand –  not be wet or sticky.

Here are some images showing a 2 week old pile being turned. We unclip the cage then transfer the whole pile back into the cage adding water as we go.



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