Tag Archives: Ingham

Using the microscope to grade compost and compost extract

This is using Elaine Ingham’s microscopy techniques to investigate thermal compost – some of what I saw. I am at an early stage of being able to do this, so any errors are mine and not Elaine Ingham’s 😉 The principle is to classify organisms by their morphology – aerobic fungi tend to have a colour, diameter wider than 2.5µm and/or have uniform septa. Spiral structures are bad, indiciative of anaerobic conditions, and ciliates (hairs all over the body) also indicate anaerobic – bad- conditions. Apart form the spirochete most of these are good.

This is on a 5x dilution, the recommended intial conditions (use 1ml of compost and make up to 5ml total with water left to stand so the chlorine has gone).

Making Compost Extract

The easiest and low-tech way of adding the microorganisms from compost is to extract them fro mthe compost using water and a mesh, then spray the water  – in our case using watering cans. You can spread the compost itself, and there’s much to be said for that, but it’s more stuff to wrangle and needs to happen before you plant, ideally. Since we are going to test areas on already growing plants, extract it is. Compost tea is a way of getting more microbes out there, but it is technically harder and we don’t have the gear. Extract it is, then. The rate seems to be about a good handful per 5 gallons, we used half an IBC, ie about 500 liters, which is 110 gallons. So we need about 20 times as much

Start with a wodge of compost in a net curtain

Start with a wodge of compost in a net curtain

and some reasonably clean borehole water (so no worries on chlorine or chloramine)

and 500 litres reasonably clean borehole water (so no worries on chlorine or chloramine)

We made a bag by putting the compost in the middle of the net curtain material and tying up the top with a releasable cable tie.

You can see the brown of the humic acid leaching out of the compost into the water

You can see the brown of the humic acid leaching out of the compost into the water

the end result is a dark brown chocolate colour

the end result is a dark brown chocolate colour

Continue reading

using the microscope with the finished compost

The successful compost is ready – it has now fallen to roughly ambient temperature.

1507_otl_AS_fourweeklyunfortunately the temperature logger failed when I was on holiday so I don’t know what the profile was as it cooled down. And yes, it didn’t spend three times three days above 55C – more like three days and two days. There’s still more to learn here.

Time to look at this and see what sort of microbial stuff is in it. I shook this up with about 20 times the amount of water and put a drop on a slide

fungal hypah and bacteria

fungal hypha and bacteria

According to Elaine Ingham’s rules of thumb this is probably a good sort of soil fungus, because if the little round cocci are 1µm in diameter the fungal hypha is about 4µm. I could see that this one was slightly tan coloured, but the incandescent lamp of the microscope plays havoc with the white balance of the camera, making everything bright yellow.

1507_hypha_DSCN2669_lznThis next one is narrow and clear, so not good in the morphology  rule of thumb that fungi < 3µm in diameter and clear are undesirable soil fungi.

I saw no protozoa or micro-arthropods. That’s either because there aren’t any or because I didn’t recognise them. The dilution is high, – it appears that Ingham starts at 5:1 so I’m four times less likely to see these at 20:1.