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2.2 Chemical Characteristics
Soil ecosystems are the driving source of transformation, transportation, and renewal of the supplies
of nutrients available to plants. It is important to remember that nutrient movement through a soil
ecosystem is very complex and that where a nutrient is in the system (soil aggregate or particle, air
or water, available or held tightly) dictates its availability for plant and organism uptake and use. We
will look at soil nutrients through the lens of requirements for plant growth, and categorize them
according to plant needs.
Nutrient Classification
Nutrients
Primary nutrients
are the nutrients needed by plants in
relatively large amounts.
Secondary nutrients
are needed by plants in substantial
amounts, but much less than the
primary nutrients.
Micronutrients
are needed by plants in small
quantities, but they play a large role in
plant growth and development.