SOILS: the real dirt

Sevier CTE Center, Feb. 2020Dr. Dianne Farrer

Other Aspects of Soil Science we don’t have time to explore …..

● Soil Fertility

● Soil Salinity

● Soil Taxonomy

● Soil Physics

● Soil Formation

● Soil Morphology

● Soil Microbiology

● Soil Conservation

What are soils?

Minerals:Sand, Silt, Clay

Soil Fraction

Diameter Description Surface Area (1 g)

Sand 0.05 - 2 mm gritty 11 cm2

Silt 0.002 - 0.05 mm floury 1130 cm2

Clay smaller than 0.002 mm sticky when wet 113,000 cm2

Minerals: Sand, Silt, Clay

Soil Organic Matter (SOM)

Additional Soil Properties:

Soil pH

Soil fertility

Soil cation exchange capacity (CEC)

Soil salts (EC & SAR)

Buffering

Resistant to

change

Soil Fertility & Soil pH

Soil Fertility16 Essential Nutrients:

● NON-Mineral Nutrients○ C - carbon

○ H - hydrogen

○ O - oxygen

● Primary Nutrients○ N - nitrogen

○ P - phosphorus

○ K - Potassium

● Secondary Nutrients○ S - sulfur

○ Ca - calcium

○ Mg - magnesium

Soil Fertility

● Micro-Nutrients○ Fe - iron

○ Zn - zinc

○ Mn - manganese

○ Cu - copper

○ B - Boron

○ Cl - chloride

○ Mo - molybdenum

Name That Plant Nutrient Deficiency/Toxicity

Calcium

Potassium

Nitrogen

Sulfur

Phosphorus

Magnesium

MICRO-NUTRIENTS

Iron

Zinc

Manganese

Copper

Molybdenum

Boron

Chlorine

Soil Organic Matter (SOM)