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So it's the first time I've properly tried to compost with an objective and it's been a horrible failure. In fact I've had better results not trying at all.
To give a bit of background, the plot I inherited had a compost heap at the back, and I replaced the pallets that were rotting with knew ones over the years. I've never really had very much biomass from the heap so the idea was to change that and turn it into a more efficient operation. In the past it just sat there.
The first mistake I made was covering the whole heap with black poly sheet, as is suggested by many tutorials. This is to stop the heap from getting too saturated, and so turning the whole thing anerobic, which is not what you want. I judged the moisture content by eye and assumed that as I was adding wet material all the time, it would all add up to something. It didn't. The heap suffered a lot from lack of moisture.
Horrible result:
The heap is compromised by about :
10% horse manure from a local stable
10% grass clippings from mowing
10% straw bought from the local stable
60% weeds pulled from the ground
10% household food waste which amounts to approximately 20-30kg every 2-3 weeks
So in this fashion the compost heap was filled to the top and then covered with the sheet and left for a few months. It's been sitting like this for about 10-12 weeks.
Why did it go wrong & observations
The centre of the heap never reached above 35 degrees. After researching, it appears anthropods should not be in compost at such high numbers, and it made me question whether the wood had something to do with it, although more likely due to dry conditions.
What I found most bewildering was the sheer amount of soil in there. I had no idea I was adding so much soil when dumping weeds.
Negatives in conclusion:
What I learnt & what to change
Clearly hosing down the heap periodically is essential
Not adding wood clippings without chopping them
Being more selective about the weeds I put in, making sure not to throw in huge lumps of clay with it as it all adds up
Layering hotter and cooler materials consecutively to get a more even chemical process
Turning it frequently
The shape of the heap is more rectangular than square, I will need to shorten it lengthwise to get a more even square. I suspect this will affect the heat generated at the centre. I added the weeds under the pretence that they would burn up, as is the common conception, but conditions never reached hot enough for this to happen.
Adding more heat, so material with a better nitrogen content, i.e. manure & more grass clippings.
Questioning the heap - getting the context right
I don't think buying in a plastic compost bin is the answer, I'm not convinced they are necessary, and there is no evidence to suggest they are any more efficient than using pallets.
Some of the compost turfed out and relocated, there are still materials like cardboard that have been in the heap for over 3 months that are practically still preserved:
In conclusion I hope someone can benefit from how not to compost and not make the same mistakes I did. As the old saying goes a mistake is only a mistake if you don't learn from it..
To give a bit of background, the plot I inherited had a compost heap at the back, and I replaced the pallets that were rotting with knew ones over the years. I've never really had very much biomass from the heap so the idea was to change that and turn it into a more efficient operation. In the past it just sat there.
The first mistake I made was covering the whole heap with black poly sheet, as is suggested by many tutorials. This is to stop the heap from getting too saturated, and so turning the whole thing anerobic, which is not what you want. I judged the moisture content by eye and assumed that as I was adding wet material all the time, it would all add up to something. It didn't. The heap suffered a lot from lack of moisture.
Horrible result:
The heap is compromised by about :
10% horse manure from a local stable
10% grass clippings from mowing
10% straw bought from the local stable
60% weeds pulled from the ground
10% household food waste which amounts to approximately 20-30kg every 2-3 weeks
So in this fashion the compost heap was filled to the top and then covered with the sheet and left for a few months. It's been sitting like this for about 10-12 weeks.
Why did it go wrong & observations
The centre of the heap never reached above 35 degrees. After researching, it appears anthropods should not be in compost at such high numbers, and it made me question whether the wood had something to do with it, although more likely due to dry conditions.
What I found most bewildering was the sheer amount of soil in there. I had no idea I was adding so much soil when dumping weeds.
Negatives in conclusion:
- adding material like tree clippings without chopping them up finely and mini-christmas trees whole
- adding weeds pulled from beds often with huge amounts of clay soil still attached to them
- inadequate layering of each material (would not prevent decomposition in any serious way, but a good thing to get right for efficiency)
- not turning it more regularly (not essential but would lead to better efficiency)
- not using an optimised shape.
- not keeping the heap at the right moisture content
What I learnt & what to change
Clearly hosing down the heap periodically is essential
Not adding wood clippings without chopping them
Being more selective about the weeds I put in, making sure not to throw in huge lumps of clay with it as it all adds up
Layering hotter and cooler materials consecutively to get a more even chemical process
Turning it frequently
The shape of the heap is more rectangular than square, I will need to shorten it lengthwise to get a more even square. I suspect this will affect the heat generated at the centre. I added the weeds under the pretence that they would burn up, as is the common conception, but conditions never reached hot enough for this to happen.
Adding more heat, so material with a better nitrogen content, i.e. manure & more grass clippings.
Questioning the heap - getting the context right
I don't think buying in a plastic compost bin is the answer, I'm not convinced they are necessary, and there is no evidence to suggest they are any more efficient than using pallets.
Some of the compost turfed out and relocated, there are still materials like cardboard that have been in the heap for over 3 months that are practically still preserved:
In conclusion I hope someone can benefit from how not to compost and not make the same mistakes I did. As the old saying goes a mistake is only a mistake if you don't learn from it..
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