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.
Digging
Begin the visual soil assessment (VSA) by digging out a 20 cm cube of topsoil.
Soil porosity
Use a slice of soil from the side of the hole to observe the soil porosity.
Earthworms
Count the number of earthworms in the cube of soil.
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.
