We are using 160901 to make compost tea. Although the temperature has fallen to ambient, it’s still a bit early. This is only seven weeks old, and it’s apparent that while all the green material and plant material has gone and isn’t recognisable for what it is, the woodchip takes longer to break down. As such it will be mainly bacterial, the fungi take longer to develop. Fungi are better at decomposing woody material. But sometimes it is not worth letting the perfect be the enemy of the good.
Compost extract was a great success but it seems to take time to take effect. The effect on the sweetcorn was marginally noticeable with only a month and a half, whereas the beans were very noticeable the next year.
If this hypothesis is true (other differences are the crops were different, and the beans and tomatoes were in the polytunnels and the sweetcorn outside) then we need to really get the compost extract out now for next year.
The 160901 compost isn’t really ready, although it has fallen back to ambient temperature, so we chose to run the experiment to get ahead. This is much more bacterial than fungal under the microscope, which is to be expected as bacterial reproduction is so much faster. But needs must in this case.
We adopted a tip from Nigel of Landews Meadow Farm in Kent and trialled using about 0.5kg of compost stirred vigorously into about 40l of water in a trug. This is more economical with the compost than the method we used last year, so we can make more extract from a given amount of compost if it works, and it is more suited to our volumes for experimentation distributing by hand. The other method is more suited to bigger volumes and mechanical spraying, because the net curtain filter screens the particle size so it is less likely to clog pumps and nozzles.
The aim is to stir fast enough to establish a vortex in the water and occasionally reverse direction. Shades of Steiner’s biodynamics here, but also a good way to aerate a volume of water by hand.
Both of our current compost heaps, 160901 and 160910 have now reached stable equilibrium. The two graphs below show the complete “heap lifetime” temperature against time. The tail of each chart is now reasonably steady, suggesting they are now “mature”. It’s between five and six weeks since we first built these heaps.
In both of these there seems to be a reasonable evenness through the pile when both temperature probes are active, the temperature recording tips of the probes were set in the centre of the pile horizontally, and at about 1/3 and 2/3 from the top of the compost heap material.
We had a quick look at 160901 compost under the microscope a little while back and it was very exciting!
Although the temperature profile wasn’t up to scratch this heap has rotted down well, so it was turned into the small container to free up the big container for the next heap. Temperature sensors were reallocated to heap 160910 but box AS retained and long probe inserted, second probe is set to monitor ambient.
The temperature of this heap was falling behind so urine added Wed 7th, 1 part urine to 3 parts water, total volume approx 2 watering cans. Thanks to members of our Community Supported Agriculture Scheme for generously supplying the urine (some particularly dedicated members even bring it to the farm from home!)