available forms of plant nutrient

Nutrient Available form
Carbon CO2
Hydrogen H2O
Oxygen H2O

,

O2
Nitrogen NH4+

 

NO3
Phosphorus H2PO4

 

HPO42
potassium K+
calcium Ca2+
magnesium Mg2+
sulphur SO24

 

SO2
iron Fe2+

 

Fe3+
zinc Zn2+
manganese Mn2+
boron H3BO3
copper Cu2+
molybdenum MoO42
chlorine Cl

In acidic soils phosphorus is available in

H2PO4

form and at alkaline pH phosphorus is available as

PO43

.