|Soil profile 1992|
The ruler is measuring the top soil and in 1992 it was about 1 foot deep. I still had not drained the allotment and the allotment was regularly waterlogged during the winter.
As far as I remember I was adding a great deal of organic matter to the soil and had double dug it but there seems to be little evidence of it in this photograph. You can see the soil is divided into very distinct horizontal layers which are called horizons. There is more organic material nearer the surface and more mineral content in the lower layers. The subsoil is mainly clay because the allotment site is on a terminal moraine left there by the Welsh glaciers.
From the booklet:" Soil Types A Field Identification Guide" I think that this is a Stagnogley. It is predominantly grey coloured with mottling present. Soils which are poorly drained ,like my soil was, and are waterlogged for a number of months during the year are often given the prefix stagno showing that stagnant water conditions occur regularly.
It would be interesting to compare this soil profile with the profile of the soil now that it has been modified by adding lots of carbon. Unfortunately, I cannot dig a hole like this because the allotment is nearly full of plants and there is no room to dig without damaging lots of plants.
The soil has now been drained using a big pipe that stretches from where the spring used to be and runs to the trackway where it flows down to the carpark. The soil is rarely waterlogged now and it is very workable in winter. I have also raised the allotment using any old organic matter I could find so that water is more likely to flow underneath the top soil.
|Bottom of the allotment 2008|
I have a simple land drain that crosses the top of this area and under the path is 12 inches of stones that take the water away to a land drain running down this side of the allotment.
This area had the very best soil on the allotment site. Unfortunately when it was tested they found some nasty chemicals and decided to change it completely.