Root depth comparisons

Download PDF here

Root depth worksheet available here

Nearly all plants have roots and for those that interact directly with soil, it is almost an essential. We can examine plant roots easily by exposing a face of soil and looking at the mat of interwoven roots that descend down the soil profile.

It is difficult in this instance to separate individual plants, especially in vegetation such as a grass sward where there are multiple individual plants. This exercise structures looking at the collective root matter and removing individual plants root system. There is also a worksheet that allows you to record what you find.

Specific learning outcomes

  • Explore and gain knowledge through interaction with plant roots about the depths they travel into the soil.
  • Consider the structure of the soil upon the development of roots and vice-versa.

Equipment for a group of 5

  • 5x 30cm clear rulers
  • Worksheet [hyperlink]
  • Water in a spray bottle
  • An already exposed soil face, OR
    • Spade with treads
    • Trowel
    • Tarpaulin

Time

  • Introduction 5 minutes maximum.
  • Optional; exposing a soil face- 20 mins
  • Measuring roots – 10 mins
  • Recording roots- 10-20 mins

Total timing 25-55 minutes.

Background learning needs

  • Understanding of the processes roots carry out for plants
  • Understanding of the processes roots carry out in soil
  • Basic understanding soil structure and root relationship

Steps

  1. Exposed soil face if needed
  2. Use water sprayer to spray the soil surfaces until the water drips down and removes soil particles with it
  3. Examine the visible roots in the profile and use the ruler to measure those which are exposed, make a note of these
  4. Use the nose of the trowel blade to tease out individual plants at the edge of the soil profile, pull the plant above ground body downwards slowly and try to locate where the roots are located within the soil
  5. Optional; record on the record sheet [hyperlink] the plant type and root depth and pattern seen eg. 10cm at deepest and spreading sideways with only ½ long roots.