An Introduction to Soil for the Cleveland Market Gardener

What is Soil?

• Air

• Water

• Mineral particles

• Organic Matter-Decomposed plant and

animal matter

• Live organisms-Bacteria, fungi, earthworms

(I like to refer to soil as a live body)

Soil composition HEALTHY SOIL 50/50

Source: University of Hawaii

How are mineral particles created?

• Weathering

• Chemical & Physical • Erosion

– Wind

– Water

• Heating, freezing and

thawing

Types of particles

• Clay “Smallest” <.002mm

• Silt 0.002-0.05 mm

• Sand “Largest” 0.5-1 mm

Soil Particles

Soil Profile

Soil Horizons • O Horizon-The tops crust organic

matter

• A Horizon-Topsoil

• E Horizon-The transition are between A &B horizon

• B Horizon-Subsoil

• C Horizon –Loosed unconsolidated material

• R Horizon-Bed rock

Soil Texture

• The relative proportion of the 3 types of particles

• Influences water-holding capacity

• Ease of cultivation

What types of soil are these?

1. 20% sand, 20% silt and 60% clay

2. 40% sand, 40% silt and 20% clay

Soil Pyramid

Source: Dannyliford.com

Soil orders

Alfisols

• Occur under deciduous woodland or

grassland in humid areas of the world

• Generally productive agricultural

• Clay enriched B horizons

MIAMIAN -- OHIO STATE SOIL The Miamian series consists of very deep, well drained soils that formed in a thin layer of loess and in the underlying loamy till, which is high in content of lime. The original vegetation consisted of deciduous forest species, principally white oak, maple, elm, ash, and hickory. Miamian soils are the most extensive soils in Ohio. They occur on more than 750,000 acres in the state. They are productive soils. Corn, soybeans, and winter wheat are the primary crops. The average annual precipitation ranges from 33 to 42 inches, and the average annual air temperature ranges from 51 to 55 degrees F.

• Miamian Soil Profile

• Surface layer: dark grayish brown silt loam

• Subsoil - upper: dark yellowish brown clay loam

• Subsoil - lower: yellowish brown clay and clay loam

• Substratum: yellowish brown loam

Soil Tilth

• Refers to the general

health of the soil

• “Ease of tilling”

Soil pH

“potential hydrogen”

• Concentration of H+

compared to distilled

water

• Logarithmic scale

Global Soil pH

Global variation in soil pH. Red = acidic soil. Yellow = neutral soil. Blue = alkaline soil. Black = no data.

Soil Structure

• The way soil in bound together in clumps known as aggregates

• Formed by the production of a by product of fungi called “glomulin”

• Ideal soils have mix of small, medium and large

Soil structure

AIR AND WATER MOVEMENT

DEPENDENT ON

PORE SPACE

• Macro pores

• Micro pores

DRAINAGE

• Rate of water movement

through and across soils

• Water should occupy

50% of pore space

Internal Drainage

• Affected by:

– Texture

– Structure

– Physical condition

The organic fraction of the Soil

Most dynamic fraction

of the soil

Humus

• Stable organic matter

• Will not break down

any further

• Sometimes refer to as

mature compost

• Advantages

• Buffer against acidic

or basic soils

• Warms up soil

• Increase water

holding capacity

Micro fauna

• Bacteria

• Fungi

• Protazoa

IMPORTANCE

CANNOT BE OVER

STATED!!!

Macro fauna

• Earthworms

• Nematodes

• Insects

• Mollusks

Where do you find macro fauna?

Cation Exchange Capacity

• The total number of

negative sites on a

clay soil or humus

• The soils ability to

absorb (exchange)

certain nutrients

• The higher the better

Soil Amendments • Something we add to the soil to improve it’s quality and or structure

• 1. Fertilizer

• 2. Peat moss

• 3. Compost

• 4. Manure

• 5. Worms

• 6. Inoculants

• 7. Sharp sand

• 8. Lime

• 9. Cover Crops

• 10. Mulches

• 11. Sewage sludge

Compost

• A mix of decayed plant

and animal matter used

to improve soil

• Everyone should do

it!!!!

• In most cases should

be used as an

amendment

Cover crops and green manures

MANY ADVANTAGES

• Some are nitrogen

fixing

• Add “tilth”

• Scavenge nutrients

Mulches

• Leaves

• Grass clippings

• Wood chips

• Cardboard

• Newspaper

Inoculants

• Bacterial

• Fungal

Peat

• Decayed plant matter

• Improve structure

• Improve water holding

capacity

• Improve lower pH

Soil Preparation for home

gardeners • Tilling

• Double digging

• Broad forking

Damaged Soil

Photo credit: Joe Boggs

How do we damage our soil

• Compaction • Working when wet

• Walking or moving

large equipment

• Over usage of tillage

equipment

• Over fertilization

How does compaction damage

soil?

• Destroys aggregates

• Destroys macro pore space

• Total pore space destructions

• Affects internal drainage

How does tilling affect the soil?

• Pulverizes soil

• Earthworms leave

• Organic matter is loss

PARTING THOUGHT

“The nation that destroys its soil destroys itself”

Franklin D. Roosevelt