1. Chapter 37: Plant Nutrition

3. Water
90% of the plants mass is water, the remaining bulk is mainly from CO2
Effects of water on the plant:
- Solvent for dissolved goods
- Gives volume for cell elongation
- Keeps cells turgid

4. Nutrients Essential Elements- Required for the plant to live
- Macronutrients- Required in large amounts (C,H, O)
- Micronutrients- Required in small amounts

5. Soil Soil- The levels of the soil can be split into horizons
- Topsoil horizon is one of the most important and is composed of
- Particles from rock
- Humus- Remains of partially decayed organic matter
- The most fertile soils are called loams and have equal amounts of sand, silt, and clay

6. LOAM

7. Water
Irrigation- H2O is usually the limiting factor of growth

8. Fertilizers- Usually Nitrogen (N), Phosphorus (P), and Potassium (K)- The N-P-K ratio is commonly seen on fertilizers.

9. Ferilizers - Nitrogen is the most important of the minerals
- Some N will come through decomposition of organic matter in the soil
- Atmospheric nitrogen (N2) cannot be used by plants so it must be turned into a usable form (ammonium or nitrate)
- Nitrogen fixing bacteria take in N2 and convert it to NH3 (ammonia) through nitrogen fixation (denitrifying bacteria do the opposite- take in NH3 and release N2)

11. Symbiotic Relationships Used to Obtain Nutrients
1. Bacteria and N fixation
- Common in legumes (beans). They have nodules which contain bacteroids

12. Symbiotic Relationships
2. Mycorrhizae (fungus roots) -Fungus gets some of the nutrients made by the plant, and the fungus increases surface area for water absorption - 2 Types

13. Symbiotic Relationships
- Ectomycorrhizae- Mycelium (fungus) forms a thick coating on a root but does not penetrate into the cells
- Endomycorrhizae- No dense coating, but the fungus hyphae penetrate into the cells

15. Other Relationships
1. Epiphytes- Grows on another plant, but does not necessarily harm the “host”

16. Other Relationships 2. Parasitic plants- Absorbs sugars and nutrients from the host

17. Other Relationships
3. Carnivorous plants- Photosynthetic, but usually live in areas with low mineral concentrations in the soil. The shortage of minerals and nutrients is supplemented by ingesting insect.