Soil Analysis

Alongside changes in vegetation within the hydrosere, there are also changes in the soil.

A soil auger is used in the field to collect soil from a known depth below the surface.  By keeping this depth consistent, you are making sure that the experiment is a fair test and you should gain more reliable results.  The corkscrew-like instrument is twisted into the soil and then pulled out.  The soil attached is collected into small plastic bags and each sample is labelled by placing a numbered piece of paper in the bag with the soil.  These are then taken back to the classroom for further analysis.

In the classroom, each soil sample was analysed to establish its pH, colour and moisture content.

pH is measured using a testing kit.  Soil, barium sulphate, distilled water and pH indicator solution are added to a test tube.  A colour chart is used to ascertain the pH of each soil samples.  Soils in Brueton Park are expected to be slightly acidic with pH values of between 5.5 and 6 (pH7 is neutral).

Soil samples were rubbed onto white paper and the colour of the soil was assessed in two ways.  Each soil was given a score from 1 to 7 based on its colour (1 was lightest, 7 was darkest). Then each soil was given a code using Munsell Colour charts by matching each soil to the colour on the charts.

Using balances, each soil sample is weighed.  This will be repeated when the sample is dry, and the difference in weight can be calculated.  This difference is the moisture content of the soil. 

In 2012, the moisture content of the samples will be high since the months of May and June have been particularly wet (i.e. prolonged antecedant rainfall).  This may have an influence on your results both for moisture content and pH.

Next Page - Collating Results