What are the Functions of Soil Organisms?
- Breakdown O.M. which makes nutrients available for uptake
- Nutirents stored in Organisms prevent nutrient loss from leaching
- Microbes produce waste products that help maintain the soil structure
- Earthworms help distribute these products through the soil profile
What is the Soil Food Web?
- The community of organisms in the soil that are all interdependant.
Why are there less living organisms on a golf course?
- Less plant diversity
- Non-target effect of pesticides
- Sandy Soils in general have less organisms
- droughty and low O.M.
- Cultural Practices deter them/kill them
Where are soil organisms found?
- In the Rhizosphere
- Litter
- Humus
- On and Between aggregates
What is the Rhizosphere and what heppens there?
- A narrow region of soil directly around the roots
- The plant’s nutrient cycling and disease suppression happens here
- Bacteria feed off sloughed off plant cells
- Protozoa and nemotodes graze on bacteria
Plant roots leak _______.
Sugars
Only _________ make some of the enzymes needed to degrade the complex compounds in humus.
Fungi
What is the result of a plant leaking sugars?
- Sugars attract microbes
what do microbes do for the plant?
- microbes help protect the plant from disease
- microbes release nutrients that the plant can use
- some microbes improve water uptake in plants
In the soil…who gets to eat first…plants or microbes?
Microbes
How much Nitrogen from the soil will a microbe take in before the plant gets a chance?
What does it do with the Nitrogen?
- up to 70% of the Nitrogen
- It turns it into gas
What are the different types of bacteria called?
- Nitrogen-Fixing Bacteria
- Nitrifying Bacteria
- Denitrifying Bacteria
What is the Seasonal Microbial Activity ?
(what time of year are they the most or least active?
They become active after the last frost of the winter…they peak in the early summer and begin to decline as summer ends and after the first frost, they rapidly decline until spring
What does Eukaryotic mean?
- Organized nucleous with a membrane
What soil organism has the highest population?
Bacteria
________ is a single celled organism.
Bacteria
Bacteria are prokaryotic, which means:
They have no nucleous
How do Bacteria play a role in the Nitrogen cycle?
They can take N2 and turn it into a form of Nitrogen that plants can use (NO3- NO4+)
Some bacteria do Denitrification…what is it?
turning NO3- NH4+ into N2
define:
Symbiotic
Mutually beneficial
What made Actinomyces so famous?
It gave us the first cure for Tuberculosis
Actinomyces dont have a nucleous….which makes them _________.
Prokaryotic
Actinomyces are multicellular.
True or False?
True
If you smell a “musty” or “earthy” smell ….. most likely it’s _________ that you’re smelling.
Actinomyces
