Essential nutrients are
-Required for normal growth and reproduction-the plant cannot complete its life cycle without these nutrients
-Required for specific structures or metabolic functions.
Nutrient
Sources
Functions
% of dry plant mass
Deficiency symptom
MACRO
-Oxygen
O2, H2O
Electron acceptor in cellular respiration; major component of organic compounds.
45%
Cell death by suffocation
Carbon
CO2
Substrate for photosynthesis; major component of organic compounds.
45%
Cell death by starvation
Hydrogen
H2O
Major component of organic compounds; electrical balance and establishment of electrochemical gradients.
6%
Cell death by dessication
Nitrogen
NO3- (nitrate), NH4+ (ammonium ion)
Component of nucleic acids, proteins, hormones, and coenzymes.
1.5%
Failure to thrive; chlorosis (yellowing of leaves)
Potassium
K+
Cofactor for many enzymes necessary for osmotic adjustment in cells; required for synthesis of organic molecules.
1.0%
Chlorosis (yellowing) at margins of leaves or in mottled pattern; weak stems; short internodes
Calcium
Ca^2+
Refulator functions; role in cell wall structure; stabilizes membranes, controls movements; second messenger in signal transduction.
0.5%
Necrosis in meristems; deformation of young leaves; stunted, highly branched root system.
Magnesium
MG^2+
Chlorophyll component; activates many enzymes
0.2%
Chlorosis between leaf veins; premature leaf drop.
Phosphorus
H2PO4- (dihydrogen phosphate ion), HPO4^2- (hydrogen phosphate ion)
Used in energetic bonds; component of nucleic acids, phospholipids, and several coenzymes.
0.2%
Stunted growth in young plants; dark green leaves with necrosis (small spots of dead cells)
Sulfur
SO4^2- (sulfate ion)
Component of protein and coenzymes.
0.1%
Stunted growth; chlorosis (yellowing)
MICRO
Chlorine
Needed for water-splitting step of photosynthesis; functions in water balance and electrical balance.
0.01%
Wilting at leaf tips; general chlorosis and necrosis of leaves or development of bronze color.
Iron
Necessay for chlorophyl synthesis; component of cytochromes and gerredoxin; enzyme cofactor.
0.01%
Chlorosis between veins of young leaves
Manganese
Involved in photosynthetic O2 evolution; enzyme activator; important in electron transfer.
0.005%
Chlorosis between leaf veins and small necrotic spots.
Zinc
Involved in synthesis of auxin, maintenance of ribosome structure, and eenzyme activation.
0.002%
Small internodes; stunted and distorted ("puckered") leaves.
Boron
Cofactor in chlorophyll synthesis; possible role in sugar transport; aids in regulation of enzyme function.
0.002%
Black necrosis (dying) in young leaves and buds.
Copper
Cofactor of some enzymes; present in lignin of xylem.
0.0006%
Dark-green leaves with necrotic spots; twisted and malformed leaves.
Nickel
Cofactor for enzyme functioning ini nitrogen metabolism.
???%
Necrosis at leaf tips.
Molybdenum
Cofactor in nitrogen reduction; essential for nitrogen fixation.
0.00001%
Chlorosis between veins; necrosis of older leaves.
(Scott Freman's Biological Science, 2ed)
All of these nutrients are necessary for plants. Lockouts occur around pHs below 5.3 and above 6.5, approximately.
Accepted pH for hydro is 5.5-6.5
For soil 6.0 is the goal.
