Nitrogen (N) :

Main Function : Component of plant proteins, chlorophyll, nucleic acids

Approx. Conc. in Plant : 1 to 6%

• Nitrate Nitrogen (NO ₃ ^- ) and Ammonical Nitrogen (NH ₄ ⁺) taken up by plant roots

• Nitrate Nitrogen (NO ₃ ^- ) mobile in the soil - Leaches readily

• Ammonical Nitrogen (NH ₄ ⁺) held to soil cation exchange

• Most Nitrogen (N) is in organic forms - Undergoes many transformations

Nitrogen (N) Deficiency of Plant :

Phosphorus (P) :

Main Function : Energy transfer ; metabolism, nucleic acids, nucleoproteins

Approx. Conc. in Plant : 0.05 to 1%

• Is taken up by plant roots as  hydrogen phosphate (H ₂ PO ₄ ^- or HPO ₄ ^2- )

• Generally not mobile in soil - Except under conditions of high soil test levels

• Plants get Phosphorus (P) by root interception

• Most available at 5.5 < pH < 7.2

• Cycles between organic and inorganic forms

Phosphorus (P) Deficiency of Plant :

Potassium (K) :

Main Function : Protein synthesis; translocation of carbohydrates; enzyme activation

Approx. Conc. in Plant : 0.3 to 6%

• Moderately mobile in the soil

• Plants obtain Potassium (K) mainly by diffusion

• Is held on the cation exchange - Greater CEC results in greater availability

• Natively Potassium (K) comes from soil minerals - Natively Potassium (K) comes from soil minerals and Added Potassium (K) can be fixed in these minerals

Potassium (K) Deficiency of Plant :