Remains of the Day, and NPK Issue 18 – 20/01/14

Start of a New Year … as wet as the old one, by the look of it;
perhaps we should slap VAT on rain – that might just put a stop to it….
….but now, a glorious brisk Sunday morning, ideal for a bit of routine maintenance….and chats with all those lovely people coming by to visit.
Remains of the Day fill our boxes and we need to make some changes, next week at the latest – the active box (No 4) is now practically full.  I combined the soggy contents of boxes 1 and 2 in box 1, so box 2 is now empty, ready to become ‘active’ . Here is the state of play:

Date             Box 1                        Box 2                          Box 3                    Box 4
19/01           Full of very wet        Empty, ready             Half full of wet      Full of fresh
stuff, part turned      to become active      stuff; tool store     stuff, ready to close

After a week of heavy rains the path along the boxes is quite muddy. I shovelled some saw-dust a kindly soul deposits behind the boxes from time to time to soak up the sludge and save our shoes….and while doing this, discovered with pleasure that someone has taken a few bags of compost I had left there for that purpose – I hope it did not prove disappointing. I moved a few more bags nearer the curb for the next gardener in need and hope they keep coming….
I am now trying out something new in our one-sided struggle with water: let’s give in gracefully and accept that we can’t keep out rainwater, so instead I arranged the contents in boxes 1 and 3 to form a pitched roof and covered it with a sheet of plastic, tucking it in all round the edges as best I could. The theory is that water entering the box will land on the plastic and then run down to the edge and out through gaps in the walls and holes drilled in the bottom, keeping our material dry and warm and aerobic and smelling sweet. Any bets on whether it will succeed?
And now, at last, the question we have all been wanting to raise but were too shy to ask: what is it we are trying to achieve by composting, apart from making us feel better …. and enriching my social life?
The key is NPK, C, plus 50-odd ‘trace elements’ essential to plant growth.
NPK is what farmers pay for when buying fertiliser: nitrogen, phosphorus and potassium (called kalium, apart from the anglo-saxons who call it potassium for reasons similar to those that persuaded us island people to drive on the left when most others in the early days of motoring chose to follow the French).
C, for carbon, is not generally a problem as it is obtained by plants from air in photosynthesis by combining CO2 and H2O in a neat trick that releases O2 – which is how we acquired our oxygen rich atmosphere in the first place.
N, P and K are the main (and potentially most problematical) plant nutrients needed to sustain growth. Lack of essential nutrients results in all sorts of problems signalled by discoloured leaves and lack of growth and fertility.
Commercial fertilizers bought by farmers are typically rated 12-10-10 – the respective values of N, P and K expressed in arcane chemical units.
‘Green’ waste contains the NPK the plant used to sustain its growth in the first place but the content in compost is very low, perhaps only 0.5-0.3-0.5, though the figures vary widely depending on origin, state and age.
The story does not end there:  vegetable matter left alone will soon be invaded by microbes of all kinds which, encouraged by plentiful food, embark on an orgy of eating, multiplying and pooing…. and being eaten by each other several times over in a complex and ever changing food chain that puts Arthur Schnitzler’s La Ronde to shamed while generating much heat and increasing the availability of nutrients in a form accessible to plants. That is a good thing…
What about the cardboard we add to the compost and any sticks and shells that get mixed in? Bacteria normally present in compost cannot cope with the molecules in which carbon usually occurs in plants but there are specialists that thrive on it, and they in turn get eaten by others … and so on….La Ronde by another name.
So:  that’s what it is all about.
Don’t you wish you had never asked?
You didn’t? Ooops – sorry.


PS  Ruth and Trish – when box 4 is full, perhaps you could switch to box 2