Soil Science Lessons 5-9 Flashcards
How many elements are necessary for plant life?
16
18 for grasses/range plants
4 Attributes of Plant Nutrients
- Promote plant metabolism
- Promote proper growth and development
- Cannot be replaced w/ another element
- Deficiency symptoms can only be remedied by supplying missing element
The 3 non-mineral plant nutrients
- Carbon
- Oxygen
- Hydrogen
The 3 plant macronutrients
- Nitrogen
- Phosphorus
- Potassium
The 3 Secondary plant Nutrients
- Calcium
- Magnesium
- Sulfur
The 2 additional nutrients required for grasses
- Silicone (Si)
- Selenium (Se)
Liebig’s Law of the Minimum
Plant production can be no greater than the level allowed by the growth factor present in the lowest amount relative to the optimum for that factor.
(Plant growth is limited by the nutrient in the least optimal amount)
What is the most common limiting nutrient?
Nitrogen
What are the 6 functions of Nitrogen?
- Promotes vegetative growth
- Provides dark green color
- Essential component of amino acids, proteins
- Essential component of DNA, RNA
- Essential component of Chlorophyll
- Increases Crop Yield
3 ways nitrogen is added to the soil
- Lightning
- Bacteria
- Fertilizer
4 Ways nitrogen is lost from the soil
- Gas
- Plant Consumption
- Runoff
- Leaching
Legume Fixation
Nitrogen fixation due to nodules on the roots of legumes
After photosynthesis, what is the most important process for life on Earth?
Nitrogen fixation
9 plant micronutrients
- Boron
- Iron
- Manganese
- Chlorine
- Copper
- Molybdenum
- Zinc
- Cobalt
- Nickle
What happens to nitrogen caused by bacterial decomposition of organic matter, and what determines which process occurs?
- Mineralization (N is released into the soil)
- Immobilization (Stored in microbial biomass)
Ratio of C to N in Org. matter determines which process occurs
What are 3 concerns of nitrate leaching?
- Represents impoverishment of ecosystem
- Can cause environmental problems
- Loss of investment if fertilizer was used
Eutrophication
Excess nutrients in a water body
Usually associated w/ nitrogen or Phosphorus
7 Functions of Phosphorus
- Stimulates early root growth
- Assists in forming ATP
- Assists in forming phospholipids
- Speeds maturity
- Assists in seed production
- Improves resistance to cold/disease
- Aids in cell division
4 Functions of Potassium in plants
- Regulates osmosis
- Promotes general health
- Produces stronger stems
- Produces plumper seeds
2 functions of calcium in plants
- Component of cell wall
- Controls soil pH
2 Functions of Magnesium
- Critical part of chlorophyll molecule
- Aids in formation of lipids
2 Function of Sulfur
- Stimulates plant growth
- Legume nodule formation