Acidity and Salt Index of Fertilizers

The following table shows the number of kilograms of lime (calcium carbonate) required to neutralize the acidifying effects of one kilogram of the fertilizer concerned.

Kg

Sulphate of Ammonia 1.14

Agran 0.61

Urea 0.83

Superphosphate NIL

Double Superphosphate NIL

Triple Superphosphate NIL

Muriate of Potash NIL

Sulphate of Potash NIL

Agras No. 1 0.94

MAP 0.59

DAP 0.64

Horticulture Special 0.51

Turf Special 0.67

NPK (blue) 0.40

NPK (red) 0.69

Iron Sulphate 0.35

Calcium Nitrate 0.20

Potassium Nitrate 0.26

Sodium Chloride (common salt) NaCl 154

Muriate of Potash KCL 114

Agran NH4NO3 105

Sodium Nitrate NaNO3 100

Urea CO (NH2) 2 75

Potassium Nitrate KNO3 74

Sulphate of Ammonia (NH4) 2SO4 69

Magnesium Sulphate MgSO4, H2O 53

DAP (NH4) 2HPO4 34

MAP (NH4) 2H2PO4 30

TSP Ca (H2PO4) 2 10

Gypsum CaSO4, 2H2O 8

Superphosphate 8

Lime CaCO3 5