1. Plant Nutrition- Ch. 37
Stephanie Ellis

2. Essential Nutrients
All minerals a plant needs to survive and reproduce
Macronutrients are needed in relatively large amounts
Micronutrients are needed in relatively small amounts

3. Soil Composition Most nutrients found in Topsoil Horizons
Sand, silt, clay
Loams are the most fertile type of soil

4. Obtaining Minerals from Soil
+ Charged minerals adhere to charged clay particles
Cation Exchange displaces the + mineral ions with H+ ions secreted by the plant’s roots

5. Obtaining Nitrogen
Nitrogen is not available directly from the atmosphere
Nitrogen fixing bacteria provide N in the form of ammonium

6. Nitrogen Fixation
N2 + 8 e- + 8 H ATP 
2 NH3 + H ADP + 16 Pi
This reaction is catalyzed by the enzyme complex nitrogenase.

7. An Adaptation for N Fixation
Legume roots have a symbiotic relationship with Rhizobium
Bacteria congregates in root nodules

8. Mycorrhizae Symbiotic relationship between fungi and plant roots
Plant gives sugars to fungus
Fungus gives PO4, other minerals, growth factors, antibiotics to plant

9. Ectomycorrhizae Endomycorrhizae

10. Parasitism

11. Carnivorous Plants

12. Mineral Deficiencies Effects of a deficiency depend on…
1. Role in plant nutrition
2. Mobility

13. Sustainable Agriculture
Goal to prevent mineral deficiencies in an economical and ecological manner
1. Fertilization
2. Irrigation
3. Preventing Erosion

14. Plant Nutrition… Goals for the Future
Increase plants’ protein production by adding more N compounds
This would greatly reduce malnutrition in 3rd world countries

15. Possible Methods Commercial Fertilization to add N compounds to soil
Hydroponic farming to provide N compounds
Synthesized catalysts modeled after Rhizobium’s nitrogenase