|
|
MINERAL NUTRITION IN PLANTS
| |
|
|
|
MACRONUTRIENTS |
|
MICRONUTRIENTS or Trace Elements |
|
C,H,O,N,P,S,K,Ca,Mg |
Fe |
Cu,Mb,Zn,B,Mn,Na,Cl |
Others occasionally required: Al,Si,Ga,Co though Al is
usually toxic
| |
ELEMENT |
UPTAKE |
USE IN THE PLANT |
DEFICIENCY SYMPTOMS |
|
 |
Nitrogen
(N)
|
NO3-
NH4+
(Amino acids, urea foliofertiliser)
|
Proteins, nucleotides porphyrins (Chlorophyll)
vitamins, Hormones |
Chlorosis (yellowing) beginning in lower leaves.
Stunted growth
Anthocyanin production. Premature abscission and
drying of the leaves |
|
Potassium
(K)
|
K+ |
Enzyme activation, osmotic control, stomatal
movement. |
Affects practically all plant metabolism.
Specifically: Mottled chlorosis in older leaves,
necrotic spots, bronzing of younger leaves, short
internodes, stunting |
|
Phosphorus
(P)
|
PO43-
HPO42-
H2PO4-
|
Nucleotides, phosphorylation, buffering, ...
Metabolism in general |
Slight yellowing, rapid abscission |
|
Calcium
(Ca)
|
Ca2+ |
Calcium pectate (cell wall),
membrane permeability,
spindle development at cell division. |
Tip death - cell division stopped, cells leaky. |
|
Sulphur
(S)
|
SO42- |
Proteins, biotin,. thymine, CoASH |
As for N but in reverse it is immobile. |
|
Magnesium
(Mg) |
Mg2+ |
Chlorophyll |
Extreme chlorosis, older leaves first - mobile |
|
Iron
(Fe) |
Fe2+
(some Fe3+) |
Precursor of chlorophyll porphyrins |
Extreme chlorosis, young leaves first - immobile. |
|
 |
Manganese
(Mn) |
|
Enzyme· activator |
Similar to- K, no bronzing |
|
Zinc
(Zn) |
|
Synthesis of auxin, Enzyme activator |
'Little leaf disease' Toxic in excess |
|
Boron
(B) |
H3BO3 |
Cell membrane transport |
Similar to Ca |
|
Copper
(Cu) |
Cu2+ |
Enzyme activator |
Tip death, stunting, premature abscission. |
|
Molybdenum
(Mo) |
Molibdate |
Electron acceptor Nitrogen metabolism |
Cauliflower whiptail disease |
|
Sodium
(Na) |
Na+ |
Synergistic with K |
Nearly always present |
|
Chorine
(Cl) |
Cl- |
Electron transport PS II |
|
|
© Paul Billiet 2012 |
The Open Door Web Site