Soil Properties

1
Soil Properties

• By Johnny M. Jessup
• Agriculture Teacher/FFA Advisor

2
What is Soil?

• Is the top layer of the Earths surface suitable
  for the growth of plant life.

3
The Soil Profile

• Soil Horizon
• They are the layers of the different types of
  soil found at different depths in the soil
  profile.
• Soil Profile
• A vertical section through the soil extending
  into the unweathered parent materials and
  exposing all the horizons.

4
Master Horizons

• Are the A, B and C horizons.
• Typically found in most soils
• They are a part of a system for naming soil
  horizons in which each layer is identified by a
  code O, A, E, B, C R.

5
The Horizons

• The O Horizon
• The organic layer made of wholly or partially
  decayed plant material and animal debris.
• Normally found in a forest with fallen leaves,
  branches and other debris.

6
The Horizons

• The A Horizon
• Also called the topsoil.
• The most fertile layer of soil.
• Contains the most organic matter.
• Usually the top or first layer.

7
The Horizons

• The E Horizon
• Also called the layer of eluviation.
• This is the zone of the greatest leaching of
  clay, chemicals and organic matter.

8
The Horizons

• The B Horizon
• Also called the subsoil.
• Called the zone of accumulation where chemicals
  leached out of the A horizon.
• Reason why most subsoil has an increase
  in clay content.

9
The Horizons

• The C Horizon
• Called the parent material.
• Lacks the properties of the A B horizon.
• Less touched by soil forming processes.

10
The Horizons

• R Horizon
• Is the underlying bedrock such as.
• Limestone
• Sandstone
• Granite

11
Soil Profiles
12
Soil Texture

• Refers to the size of particles.
• Three types are.
• Sand (Large)
• Silt (Medium)
• Clay (Small)

13
Relative Size of Soil Particles
14
Soil Texture - Sandy

• The largest of the soil particles.
• Individual particles can be seen with
  the naked eye.
• Low moisture-holding capacity.

15
Soil Texture - Loamy

• About equal parts of.
• Sand
• Silt
• Clay
• Ideal texture for most non-container outside
  plants.

16
Soil Texture - Clayey

• The smallest of the soil particles.
• Clay particles stick to one another.
• Has a high water-holding capacity.

17
Textural Classes

• There are 12 textural classes.
• Represented on the Soil Texture Triangle.
• Textural class determined by the percentage of
  sand, silt, clay.

18
(No Transcript)
19
Soil Structure

• Refers to the way soil particles cling together
  to form soil units or aggregates, while leaving
  pore space to.
• Store air.
• Store water.
• Store nutrients.
• Allow root
  penetration.

20
Types of Soil Structures

• There are five types of soil structures.
• They are
• Single grain
• Granular
• Platy
• Blocky
• Prismatic

21
Soil Structure Single Grain

• Associated with sandy soils.

22
Soil Structure - Granular

• Is the best for most plants.
• Particles cling together to form rounded
  aggregates.
• It is commonly found in A horizons.
• Peds are small usually between 1 to 10
  millimeters.

23
Soil Structure - Platy

• Usually found in E horizons.
• Large, thin peds.
• Plate-like arranged in overlapping horizontal
  layers.

24
Soil Structure - Blocky

• Particles cling together in angular aggregates.
• Typical of soils with high clay content.
• Typical of B horizons.
• Peds are large about 5 to 50 millimeters.

25
Soil Structure - Massive

• Soil has no visible structure.
• Hard to break apart appears in very large clods.

26
Soil Structure

• More important to producers who grow plants in
  natural soils because.
• Producers of container grown plants add
  ingredients to make growing media desirable.

27
Soil Composition

• About 50 of the soil should be solid particles.
• 45 - Minerals
• 5 - Organic Matter
• About 50 of soil should be pore space.
• 25 - Air/Pore Space
• 25 - Water

28
Soil pH

• pH has the most impact on the availability of
  nutrients in the soil/media.
• pH Scale
• Ranges from 0 to 15.
• Indicates the level of acidity or alkalinity.
• 7 is considered neutral.
• Everything greater than 7 is considered alkaline
  (basic).
• Everything less than 7 is considered acidic.

29
pH Scale
30
Ideal pH

• The ideal pH of most ornamental plants
  lawn/turfgrasses is 5.5 to 7.0.

31
Ph Scale Review

• What would be a pH of 7.0?
• Neutral.
• What would a Ph pf 3.5 be?
• Acidic.
• What would a pH of 9.0 be?
• Alkaline.

32
Land Capability

• Based on the physical, chemical, and
  topographical aspects of the land.

33
Land Capability Classes

• Assigning a number to
  land.
• Eight classes used.
• I to VIII with I having the
  best arability.
• Class I to IV can be cultivated.
• V to VIII tend to have high slope or are low
  wet.

34
Land Capability Classes

• Class I - Very good land.
• Very few limitations.
• Deep soil and nearly level.
• Can be cropped every year as long as land is
  taken care of.
• Class II - Good land
• Has deep soil.
• May require moderate attention to conservation
  practices.

35
Land Capability Classes

• Class III - moderately good land.
• Crops must be more carefully selected.
• Often gently sloping hills.
• Terraces and strip-cropping are more often used.
• Class IV - fairly good land.
• Lowest class cultivated.
• On hills with more slope than class III.
• Class V - Unsuited for cultivation.
• Can be used for pasture crops and cattle grazing,
  hay crops or tree farming.
• Often used for wildlife or recreation areas.

36
Land Capability Classes

• Class VI - Not suited for row crops.
• Too much slope.
• Usually damaged by erosion with gullies.
• Can be used for trees, wildlife habitat, and
  recreation.
• Class VII - Highly unsuited for cultivation.
• Has severe limitations.
• Best used for planting trees.
• Steeply sloping.
• Large rock surfaces and boulders may be found.
• Very little soil present.

37
Land Capability Classes

• Class VIII Cannot be use for commercial plants.
• Cannot be used for row crops or other crops.
• Often lowland covered with water.
• Soil maybe wet or high in clay.
• Best suited for wildlife recreation.

38
Designed By

• Johnny M. Jessup, FFA Advisor
• Hobbton High School