Make your own fieldwork equipment: Soil compaction

What you need

• Knitting needle

• Ruler

What you do

Create your own soil pins using knitting needles. Push the needle into the ground as far as it will go before you feel resistance. Measure the depth. Take care when carrying and using knitting needles, they should be carried to the site in students' bags, not in their hands.

When you use it

Compare levels of compaction at different sites and in different soil types, for example during a study of footpath erosion or trampling. Can be used in conjunction with infiltration equipment to determine why rates of infiltration vary between sites, and that impact that compacted and saturated soil can have on agriculture or on flood risk. The equipment can also be used to compare vegetated and cleared land as a small scale representation of the consequences of rainforest clearance.