This document discusses soil properties for growing plants and turf. It explains that greenhouse growers mix different soil-less materials together to make a soil suitable for growing plants inside that does not contain insects, diseases or weeds. Some common organic materials used include peat moss, compost, sphagnum moss and bark, while common inorganic materials include vermiculite and perlite. Horticultural soils have advantages like being sterile, having a neutral pH, and being disease and weed free. The document also covers soil structure, texture, pH, physical properties and the process for soil sampling and testing.

1. SOIL PROPERTIES
FOR GROWING
PLANTS AND TURF
By: Jon Hill Turf

2. Soils and growing media
■ Soils and growing media are made up of two
types of materials
– Organic matter
– Inorganic compounds

3. Growing Media
■ When growing plants in a greenhouse, dirt from the
ground cannot be used because it may contain:
■ Insects
■ Diseases
■ Weeds
■ Greenhouse plant growers will mix different soil-less
materials together to make a soil suitable for growing
plants inside of a greenhouse in containers.

4. Organic Soil-less Media Components
■ Media is
– any matter, excluding organic soil, used for
the production of horticultural plants.
– Soil-less media does not contain natural soil.
The soil is replaced by other materials

5. Organic Matter (OM)
■ Dead plant or animal tissue
■ contains carbon
■ usually has diseases or insects

6. Types of Organic Soil-less Media
Peat Moss
■Organic and has a slightly acidic pH
■Partially decomposed material mined from the
swamps
■Has good moisture holding properties

7. Types of Organic Soil-less Media
Compost
•Decayed organic matter
•Compost is used for soil conditioning and fertilizer.

8. Types of Organic Soil-less Media
Sphagnum Moss
•Sphagnum is organic and is very acidic
•Dehydrated remains of acid bog plants
•Holds moisture
•Commonly used line wire hanging baskets

9. Types of Organic Soil-less Media
Bark
•Organic and slightly
acid pH
•Larger matter added to
some horticulture media
to promote drainage
•Adding bark to a
soilless mix usually
makes the mix heavier
•Widely used in tree and
shrub production

10. Additional Organic Materials
Used in Soil-less Media Mixes
■ Sawdust and Wood Shavings
– Have a high carbon to nitrogen ration
– Make nitrogen unavailable for plant use
■ Organic materials must be well rotted or decomposed to
avoid problems with nitrogen tie-up.

11. Inorganic compounds
■ Do not contain carbon
■ usually sterile

12. Types of Inorganic Soil-less Media
Vermiculite
•A light-weight mica mineral matter commonly used
to start seed and cuttings.
•Inorganic and has a slightly alkaline pH
•Holds moisture

13. Types of Inorganic Soil-less Media
Perlite
A natural volcanic material
Slightly alkaline pH
Helps with soil aeration and drainage

14. Advantages of horticultural soils
1. Sterile.
2. pH is neutral.
3. Disease and weed free.
4. It is good for starting disease sensitive seeds
• Tomato
1. It is easy to control the nutrient content
2. Improves crop uniformity.
3. It is easy to create a horticulture soil for
particular plant needs.

15. Disadvantages
1. Expensive
2. It is light weight

16. SOIL PROFILES
AND SAMPLING

17. Soil Profile
■ Soil layers are
called horizons
■ All soil profiles do
not have the same
number of horizons
■ Most typical soils in
NC will have a
minimum of the A,
B, and C or R
horizons.

18. O Horizon
• Rich Soil found
where a plant cover
has been in place for
an extended time
• Is rich in Organic
Matter.
• Dark in Color
• Most fertile layer
in the soil
A Horizon
• The topsoil and
most fertile in the
absence of an O
Horizon
• Home to
earthworms and soil
organisms
• Brown in color
Soil Profile

19. B Horizon
■Subsoil
■Clayey soil with high mineral
content
■Brown to Reddish in Color
C Horizon
■Parent Material
■Mostly Clumps of un-
weathered rocks
R Horizon
■Bedrock
■Very few roots can penetrate

20. Soil Structure
■ How particles cluster together
– single grain
– granular (best for most plants)
– blocky
– platy
– massive

21. Soil Structure
■ Soil structure is more important to producers who
grow plants in natural soils
■ Producers of container grown plants add
ingredients to make growing media desirable
■ Granular soil structure is the best.
– Plants have good root development
– Water movement is at an appropriate rate

22. Soil Texture
■ Size of particles
■ Types of textures
– clayey
– loamy
– sandy

23. Clayey Texture
■ Small particles
■ Has a high water-holding capacity
■ most common texture in western NC

24. Silt
■ Medium sized particles
■ Good moisture and nutrient holding capacity

25. Loamy texture
■About equal parts of sand, clay
and silt
■Ideal texture for most non-
container outside plants

26. Sandy texture
■ Large particles
■ Low moisture-holding
capacity
■ Most common in eastern
NC

27. Soil pH
■ Measurement of acidity or alkalinity
from 0 to 14
– Acid-less than 0-6.9
– Alkaline-more than 8-14
– Neutral - 7
■ Most organic matter is acid
■ Most artificial media is neutral
■ Ideal pH for most gardens is 5.5 to
7.0
■ Lime will raise the pH value in soils
■ Calcium or sulfur will lower the pH
Value

28. Physical Properties of Soils
■ Permeability
– rate at which water moves through the soil
■ Water holding capacity
– ability of a soil to hold water for plant use
■ Porosity
– amount of air space between soil particles

29. Physical Properties of Soils
■ 50% of soil should be pore
space
– 25% water space
– 25% air space.
■ 50% of soil should be soil
particles
– 45% mineral matter
– 5% organic matter

30. Soil Sampling
■ Soil sampling and testing is essential for an
accurate fertilizer recommendation for growing
plants.

31. Soil Sampling
Procedures1. Create a visual grid of the area to be
planted.
• For gardens and landscapes, take 5-10 sub-
samples
• Sample before the growing season.
1. Use a stainless steel soil-sampling probe.
2. Take the surface sample to tillage depth
1. about 4inches for lawns
2. 6-8 inches for crops
3. Mix the soil samples together.

32. Soil Sampling
Procedures5. Remove any grass, rocks or other material besides soil.
6. Avoid unusual spots
• Problem areas need to be sent in a separate box.
5. Place soil samples in a box
• Obtain from the County Extension Office along with
Soil Sample Information sheet
5. Send the box and information to:
• Agronomic Division Soil Test Lab in Raleigh for a free
soil test.

33. FFA Land Judging CDE

34. Thanks