1. Plant Nutrition: N,P and K

2. Plant Nutrition: N,P and K
Nutritional needs
Autotrophic does not mean autonomous
plants need…
sun as an energy source
inorganic compounds as raw materials
water (H2O)
CO2
minerals

3. Plant Nutrition: N,P and K
Macronutrients
Plants require these nutrients in relatively large amounts: C, O, H, N, P, K, Ca, Mg, S

4. Plant Nutrition: N,P and K
From where and for what? C
macromolecule synthesis
CO2 O H
macromolecule synthesis & proton pumps
H2O N
protein & nucleic acid synthesis
soil P
nucleic acids, ATP, phospholipids K
stomate control, water balance Ca
cell wall & membrane structure, regulation Mg
chlorophyll S
proteins, enzymes

5. Plant Nutrition: N,P and K
Micronutrients
Plants require in very small amounts
Cl, Fe, Mn, Bo, Zi, Ni, Mb
primarily cofactors for enzyme function

6. Plant Nutrition: N,P and K
Nutrient Deficiencies
Lack of essential nutrients
exhibit specific symptoms
dependent on function of nutrient
dependent on solubility of nutrient

7. Plant Nutrition: N,P and K
Nutrient Deficiencies
Low Nitrogen Crop

8. Plant Nutrition: N,P and K
Magnesium Deficiencies
Symptoms
chlorosis = yellowing of leaves
Why? What is magnesium’s function?

9. Plant Nutrition: N,P and K
Magnesium Deficiencies

10. Plant Nutrition: N,P and K
Soils
Plants are dependent on soil quality
texture / structure
relative amounts of various sizes of soil particles
composition
organic & inorganic chemical components
fertility

11. Plant Nutrition: N,P and K
Soils
Topsoil
most important to plant growth
rich in organic matter
humus
decomposing organic material
breakdown of dead organisms, feces, fallen leaves & other organic refuse by bacteria & fungi
improves soil texture
reservoir of minerals
organisms
1 tsp. of topsoil has ~5 billion bacteria living with fungi, algae, protists, insects, earthworms, nematodes

12. Plant Nutrition: N,P and K
Soils Conservation
Not taking care of soil health has far-reaching, damaging consequences
1920’s Dust Bowl
lack of soil conservation
growing the same crop year after year (wheat)
grazing by cattle
bare ground exposed to wind erosion in winter
drought

13. Plant Nutrition: N,P and K
Soils Conservation
Soil conservation & sustainable agriculture
maintaining healthy environment
sustainable production of food supply
economically viable farming industry
contour plowing
cover crops
crop rotation

14. Plant Nutrition: N,P and K
Global Issues
soil fertility
erosion
irrigation
forestry destruction

15. Plant Nutrition: N,P and K
Fertilizers
“Organic” fertilizers
manure, compost, fishmeal
“Chemical” fertilizers
commercially manufactured
N-P-K (ex )
15% nitrogen
10% phosphorus
5% potassium

16. Plant Nutrition: N,P and K
Nitrogen Uptake
Nitrates
plants can only take up nitrate (NO3-)
Nitrogen cycle by bacteria
trace path of nitrogen fixation!

17. Plant Nutrition: N,P and K
Nitrogen Uptake

18. Plant Nutrition: N,P and K
Soybean Root Nodules
N fixation by Rhizobium bacteria
symbiotic relationship with bean family (legumes)

19. Plant Nutrition: N,P and K
Soil Augmentation: Changing Fertility
Cover crops
growing a field of plants just to plow them under
usually a legume crop
taking care of soil’s health
puts nitrogen back in soil

20. Plant Nutrition: N,P and K
Plant Oddities
Pitcher Plant: Bog Plant
Mistletoe: parasitic
Venus Fly Trap: Bog Plant

21. Plant Nutrition: N,P and K
What is a Bog?
High acid environment
most minerals & nutrients bound up & are not available to plants
must find alternative sources of nutrients

22. Any Questions?