1. Soil Organisms Dr. Lori Gourneau Cankdeska Cikana Community College
NDEPSCOR/NDSU/NATURE
SUMMER CAMP 2017

2. Soil Organisms Soil is full of living organisms
How many organism are in the soil?
What types of organisms are in the soil?
Why are they important?

3. Soil Organisms

4. Soil is Alive How many organism are in the soil?
10^7 to 10^9 bacteria per cm3
10 to 1000 protozoa per cm3
10^3 to 10^6 fungi per cm3
1.3 gm soil = 1 cm3

5. Soil Types

6. The Five Kingdoms: soil organisms
Animalia
Plantae
Fungi
Protista
Monera (bacteria)

7. Soil Organisms

8. Facts: Soil Organisms Soil Microorganisms - Small, Plentiful, Powerful
Even with a decent microscope soil bacteria, if visible, are only specks. To really see their form you need an electron microscope - definitely outside the budget range of the average gardener or farmer.
Consider this:
250,000 bacteria could fit on a spot the size of a period.
A billion bacteria live in a single gram of soil.
A healthy acre of land will be home to about a ton and a half soil bacteria, equivalent to about two cows worth of life below the ground on four average size residential lots.
We think tropical rainforests have incredible biodiversity. About half the 10 million plant, animal and insect species are found there.
According to calculations published in Science in 2005, researchers at the Los Alamos National Laboratory estimated that a single gram of pristine soil contains close to a million distinct species of bacteria.
Reference:

9. Function: Soil Organisms
Bacteria and Fungi – are the foundations of the web
They help to hold nutrients in the root zone for your plants
Build soil structure so that water both drains and holds better
Help prevent soil erosion
Produces plant stimulating hormones
They help to fix nitrogen from nitrogen gas to plant usable nitrogen
They help to make phosphorous available for plants
Open the soil so that plant roots can penetrate more deeply
Compete with bad guy bacteria and fungi thus keeping them in check and helping plants fight disease or stay disease free
The other soil organisms, the protozoa, nematodes and other larger members of the soil food web eat the bacteria and fungi and in doing so release the nutrients the plants need when they need them. Pretty amazing really.
Reference:

10. Web of Soil Organisms

11. Soil Organisms: microorganisms
Bacterial Shapes

12. Soil Bacteria Prokaryotic, unicellular, many shapes
Most numerous of soil organism

13. Actinomycetes Special class of bacteria, prokaryotic
Look more like fungi
Give the earthy smell of fresh soil – geosmin (organic compound) produced by actinobacteria, dominant in alkaline (basic) soils

14. Soil Fungi Live off dead or living plant, animal, microbial remains
Yeasts, filamentous fungi, mushrooms, molds

15. Soil Protists Unicellular organism
Act as grazers, prey on bacteria & fungi

16. Soil Plants Algae Microscopic plants in soil
Algal blooms- green carpet of growth on warm moist soil

17. Soil Animals Burrowing animals: moles, mice
Earthworms: digest plant & animal remains
Arthropods: ants, termites, centipedes
Nematodes: microscopic worms- eat decaying organic material

18. Soil Organisms Activity #2A: 20-30 minutes
Soil Organism Worksheet: Please fill out the table completely using your computer as a resource.
Answer the questions at the bottom of the table.
Discussion