Key Terms
Three criteria must ALL be met
1. The plant cannot complete its life cycle without it 2.
Nine total
Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Sulfur
Calcium does double duty
Nutrient transport AND enzyme support.
Ten total
Iron (Fe), Manganese (Mn), Boron (B), Molybdenum (Mo), Copper (Cu), Zinc (Zn), Chlorine (Cl), Nickel (Ni), Cobalt (Co),
Soil
The outer loose layer covering Earth's surface. Soil quality determines plant distribution and growth alongside climate.
Autotrophic plants
Make their own food via photosynthesis; use CO2, water, sunlight. Heterotrophic (holoparasitic) plants: no chlorophyll;
Nitrogen is critical
It is part of nucleic acids and proteins. Atmospheric nitrogen (N2) is the largest nitrogen pool in terrestrial ecosyste
Solution
Biological nitrogen fixation (BNF). BNF = conversion of N2 to ammonia (NH3) by prokaryotes (soil bacteria or cyanobacter
Key enzyme
Nitrogenase. It reduces N2 to NH3.
Most important BNF source
Symbiosis between rhizobia (soil bacteria) and legume roots.
Problem
Nutrient depletion zones develop around roots when uptake is faster than diffusion; soil moisture is low; or nutrient co
Mycorrhizae
Symbiotic fungus-root associations; improve mineral uptake
Example
Dodder (wraps around host, forms suckers that tap into vascular tissue)
Essential nutrient
Element required to complete the plant life cycle; no substitute; directly involved in plant nutrition
Macronutrient
Required in large amounts (C, H, O, N, P, K, Ca, Mg, S)