Taking on the 'Soil my Undies' challenge

Finding out how much life is in garden soil can be done by burying a pair of cotton pants and seeing how long they take to disappear, so let's do it!

Pieces of cotton fabric and elastic to be buried in various gardensLife in the soil is a vital part of growing success; the tiny life forms (nematodes, arthropods, protozoa, bacteria) are just as important as the more visible ones like earthworms, centipedes beetles and fungal mycelium.

This teeming community, often called 'soil biology', is the backbone of a healthy garden and a good indicator of soil health. They are the ones breaking down organic matter to release nutrients, mixing it all in and aerating the soil in the process. As the soil microbiologist Elaine Ingham said, without the biology, you don't have soil you have 'dirt'. 'Soil' is alive and what you grow in, she says, while 'dirt' is dead and what ends up on the doormat as you stamp your way into the house. You wouldn't think of sweeping it up and planting in it.  

Dishing the dirt on 'dirt'

How can you find out about your garden soil health? You can send a sample away to be analysed, numerous laboratories offer a service. A cheap and simple home method, however, is being used by farmers and growers around the world and it couldn't be easier. You simply to bury a pair of 100% cotton underpants for two or three months and then dig them up to see how they've fared. If your soil is healthy and full of life, the pants should have little left but strips of rag and the elastic waistband. For poor soil with little life in it, the pants might come out almost as good as new, at least after a good hot wash. 

Cotton fabric and a strip of elastic buried in the soilHaving read a few articles on the 'Soil my Undies' challenge and seeing the pictures of smiling farmers and gardeners holding up ragged pants, showing off how healthy their soil is, I had to try it. I couldn't bring myself to go out and buy new underwear just to bury it, nor could I see myself taking them from my beloved's underwear drawer, and certainly not if they're going to be photographed. We do, however, have a plentiful supply of old work shirts, which we cut into pieces and use when oiling tools or re-waxing hats. I also found some ancient and unusable elastic at the bottom of my sewing kit which would stand in for the waist band of the underpants. 

I thought a good place to start would be one of the raised beds we use to grow vegetables. The one I decided on had been used for shallots and garlic first and later sown with buckwheat to see if the bees would use it for forage. Sadly, they completely ignored it, so I chopped it down, intending to dig it in.

The stems had lain on the soil surface for some weeks and today seemed as good a time as any to dig them in and bury the first pieces of cotton and elastic at a depth of 10cm. Cold weather is approaching so the soil fauna may not as active as during warmer weather, but they don't down tools for winter, they carry on working. To be on the safe side, I'll leave the cotton buried for three months and dig them up on February 13, 2018. It will be interesting to see what has happened in that time and I hope to find only the elastic remaining. 

See also

RHS advice: Soil care

RHS advice: Soil types


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