Activity

Visual soil assessment

In this activity, students learn about soil quality and soil properties by conducting a visual soil assessment (VSA). The activity involves digging up a 20 cm cube of soil to examine the soil structure and porosity and look for earthworms. This simplified VSA can be done at school or on a farm pasture.

Feet of teacher and students digging out a 20 cm cube of topsoil

Digging

Begin the visual soil assessment (VSA) by digging out a 20 cm cube of topsoil.

Rights: The University of Waikato Te Whare Wānanga o Waikato
Holding a slice of soil to observe the soil porosity.

Soil porosity

Use a slice of soil from the side of the hole to observe the soil porosity.

Rights: The University of Waikato Te Whare Wānanga o Waikato
Hand holding soil with earthworms in it outside.

Earthworms

Count the number of earthworms in the cube of soil.

Rights: The University of Waikato Te Whare Wānanga o Waikato

By the end of this activity, students should be able to:

  • identify why soil structure, porosity and earthworms are indicators of soil quality

  • discuss how land use can affect soils

  • conduct a simplified version of a visual soil assessment.

Download the Word file for:

  • introduction/background notes

  • what you need

  • what to do

  • discussion questions

  • extension ideas

  • student handout

  • visual scoring references.

Nature of science

Farmers and others need reliable tools to help them make decisions that lead to sustainable land management. The visual soil assessment was developed as an inexpensive, effective diagnostic tool that provides immediate results that are easy to interpret and understand.

Related content

If you are doing a visual soil assessment in the months of June through September, contribute information from your earthworm count to the citizen science project The Great Kiwi Earthworm Survey. You will be helping researchers improve their understanding of earthworm abundance and diversity.

Useful links

To learn more about conducting a full VSA or to download field guides for cropping or pastoral grazing on flat country or hill country, visit the Landcare Research website.

Published: 30 July 2013,Updated: 30 July 2013