Soil Tech Note 8A- Actinomycetes

Actinomycetes

PROBLEM: “Somebody actually told me that some bug in the soil makes it smell good. I can’t believe that!”

INFORMATION WANTED:

• Yes, one of the microbial species in the soil, Actinomycetes, produces a chemical called Geosmin which gives the “earthy” somewhat “clean” smell in newly disturbed soils.
• Actinomycetes have filaments that help form stable organic aggregates in the soil.
• These are a form of bacteria but visually similar to fungi. Form strands of hyphae that permeate the soil and help bind it together.
• Degrade the more resistant parts of the soil organic matter, such as cellulose and lignin.
• Predominantly live in the rhizosphere.

POSSIBLE SOLUTIONS TO INCREASE ACTINOMYCES IN THE SOIL:

• Cover crops provide the plant diversity which will help to feed these microbes as they do with fungi.
• Avoid as much tillage as possible. Physically destroys the material they feed on.
• Tillage can also produce hard pan in soil, which prohibits air and water movement. Can make the soil surface too dry or too wet for all microbes.
• Watch pH levels, as these microbes like neutral to slightly acid conditions.
• Actinomycetes need moisture, but are aerobic in nature. Residue cover on surface will protect against excessively high soil surface temperatures.