Rhizosheaths are coatings of soil particles that cling to plant roots, making roots brown instead of white. They are a sign of biological/microbial 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 therefore indicates the formation of good soil structure.
Rhizosheath development helps plants to cope with water stress, nitrogen and phosphorus deficiencies, and soil acidity. Biology and exudates around rhizosheath can buffer plants up to a pH of 2 units. This zone also provides a buffer against high Al and Na.
N.B. Some species do not form rhizosheaths, such as cultivars in the brassica, allium & asparagus family.
What to record
- Score
- 0. None, roots white. No soil covering
- 1. Some roots coated. Some roots have partial or full coating
- 2. Most or all roots coated. Most roots are fully coated
- Photos
- 0. None, roots white. No soil covering
- 1. Some roots coated. Some roots have partial or full coating
- 2. Most or all roots coated. Most roots are fully coated
Equipment
- Spade
- Gloves
How to do the test
