Rhizosheaths are coatings of soil particles that cling to plant roots, making them brown instead of white. They are a sign of biological activity in the rhizosphere (root zone). Soil particles are bound to the roots by biotic glues, secreted by microorganisms. This is aggregation in action and indicates the formation of good soil structure.
Rhizosheath development helps plants to cope with water stress, nitrogen & phosphorus deficiency, and soil acidity. Exudates around rhizosheaths can stabilise plants’ pH, and buffer against high Al and Na.
N.B. Some species do not form rhizosheaths, such as cultivars in the brassica, allium & asparagus family.
You can do this test at the same time as other spade tests such as the VESS test.
What to record
Record rhizosheath score (0-2)
Make notes: Anything interesting you’ve noticed!
A smartphone (with Sectormentor downloaded)
How to do the test
1. Head to the chosen sample area, and dig out a section of soil as big as your spade. (can be done at the same time as VESS or other spade tests)
2. Gently break soil away from roots and shake gently so loose soil breaks away.
3. Observe if there is any soil that seems attached to the roots, and score as follows: 0 = roots white, no soil covering, 1 = some roots partly covered, 2 = many / most roots coated with soil.
4. Done! Remember to ‘Sync’ your app when you’ve finished and take a photo for future reference.