Over the past few months, I've been using horse stable sweepings for compost-making. I'm improving my technique through trial and error and some research.

I currently have quite a big heap, and every time I mow my lawn, I then turn the heap, mixing in my fresh grass-clippings for added nitrogen. Once the lawn needs mowing much less often due to winter's onset, I will probably leave the heap alone to finish rotting down over winter.

Initially, every time I turned the heap, I was finding that the hot core of the heap had turned into something that looked like very dry, grey ash. Is that indeed what it was? I presume this was caused by the high temperatures that develop inside the heap, due to microbial/chemical action.

I find that this doesn't occur if I take a broom handle and poke a lot of deep ventilation tunnels into the heap. I initially started doing this because I read that oxygen is required by the microbes that help with the decomposition of the compost. However, I have also read that heat is a necessary requirement for compost-making! However, I would imagine that the kind of heat that turns vegetable matter into ash, would also kill bacteria!

So my question is: Which is more important for making good quality compost, fairly quickly; heat or oxygen? Perhaps the answer is 'a bit of both' in the right balance. What do you think?

Many thanks!

Al

On 29/10/2017 11:27, Al_4 wrote:
Over the past few months, I've been using horse stable sweepings for
compost-making. I'm improving my technique through trial and error
and some research.

I currently have quite a big heap, and every time I mow my lawn, I
then turn the heap, mixing in my fresh grass-clippings for added
nitrogen. Once the lawn needs mowing much less often due to winter's
onset, I will probably leave the heap alone to finish rotting down
over winter.

Initially, every time I turned the heap, I was finding that the hot
core of the heap had turned into something that looked like very dry,
grey ash. Is that indeed what it was? I presume this was caused by
the high temperatures that develop inside the heap, due to
microbial/chemical action.

It has managed to get hot enough to smoulder. I've had my heap to it to
the interior a few times usually after adding a large amount 1m^3 of
grass cuttings in a single session. You also get a funny smell of short
chain fatty acids a couple of days after adding them as the internal
temperature starts to soar. It takes a big heap and a lot of material
all added at once and loosely for it to go so well.

I don't turn mine all that often. I just put new stuff on top and mix up
the dry top surface with the new material a bit.

I find that this doesn't occur if I take a broom handle and poke a
lot of deep ventilation tunnels into the heap. I initially started
doing this because I read that oxygen is required by the microbes
that help with the decomposition of the compost. However, I have also
read that heat is a necessary requirement for compost-making!
However, I would imagine that the kind of heat that turns vegetable
matter into ash, would also kill bacteria!

The holes are letting some of the heat out and preventing it getting hot
enough to start smouldering. You will have more compost as a result.

So my question is: Which is more important for making good quality
compost, fairly quickly; heat or oxygen? Perhaps the answer is 'a bit
of both' in the right balance. What do you think?

Some of each. Ash still has the mineral content but no bulk. In an ideal
world you want the heap to get upto 60-70C internally and stay there
until stuff has been digested. A mix of grass and some woody bits helps
keep things under control. A hot heap will eat quite woody prunings.

--
Regards,
Martin Brown

On Tuesday, October 31, 2017 at 9:22:43 AM UTC, Martin Brown wrote:

Some of each. Ash still has the mineral content but no bulk. In an ideal
world you want the heap to get upto 60-70C internally and stay there
until stuff has been digested. A mix of grass and some woody bits helps
keep things under control. A hot heap will eat quite woody prunings.

Thanks for your input, Martin. So it *was* ash! I think I'll continue with my hole-poking method after reading your reply.

Al

On 02/11/2017 17:50, Al_4 wrote:
On Tuesday, October 31, 2017 at 9:22:43 AM UTC, Martin Brown wrote:

Some of each. Ash still has the mineral content but no bulk. In an ideal
world you want the heap to get upto 60-70C internally and stay there
until stuff has been digested. A mix of grass and some woody bits helps
keep things under control. A hot heap will eat quite woody prunings.

Thanks for your input, Martin. So it *was* ash! I think I'll continue with my hole-poking method after reading your reply.

Al

I'd be inclined to pour water into each hole you punch to keep the
centre of the heap moist.

On 02/11/2017 20:31, David wrote:
On 02/11/2017 17:50, Al_4 wrote:
On Tuesday, October 31, 2017 at 9:22:43 AM UTC, Martin Brown wrote:

Some of each. Ash still has the mineral content but no bulk. In an ideal
world you want the heap to get upto 60-70C internally and stay there
until stuff has been digested. A mix of grass and some woody bits helps
keep things under control. A hot heap will eat quite woody prunings.

Thanks for your input, Martin. So it *was* ash! I think I'll continue
with my hole-poking method after reading your reply.

Al

I'd be inclined to pour water into each hole you punch to keep the
centre of the heap moist.

With mine it is generally the surface that dries out quickest aided and
abetted by the hot interior. Steam rising on cooler mornings. I
generally spray it over with water before turning to compensate.

--
Regards,
Martin Brown