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

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.

I looked at a sample of this compost extract with the microscope. The concentration of organisms seemed low, certainly a lot lower than the 5:1 sampling recommended for compost. This isn’t that surprising – there was less than 20% of the total volume of compost used, and the net material will have held back a lot.

Nevertheless I saw a few fungal hyphae that were wide and tan-coloured, and some testate amoebae

The end result was added to marked plots using a watering can. Some of the plots were given the compost extract, while others in the same bed were given water without compost extract to act as a control.