NPK fertilisers

What are NPK fertilisers

• Contain water soluble compounds containing nitrogen (18%, Phosphorous 24% and Potassium 12%)

• Help crops grow to increase yield

• Different formulations for different crops

Why are NPK fertilisers used on crops?

Help crops grow + increase crop yield

What are 2 sources of most of the salts in NPK fertilisers?

Mined and Manufactured

Why can phosphate rock not be used as a fertiliser?

It is insoluble therefore it won’t be absorbed by the soil

Many salts in fertilisers are ammonium salts made from ammonia. In what other way is ammonia used to make salts for fertilisers?

Used to make nitric acid for nitrates

Which salts are in single superphosphate fertilisers?

Calcium phosphate + calcium sulphate

Which salts are in triple superphosphate fertilisers?

Calcium phosphate

Ammonium nitrate

NH4NO3, manufactured, nitric acid + ammonium hydroxide

Ammonium sulphate

(NH4)2SO4, manufactured, sulphuric acid + ammonium hydroxide

Ammonium phosphate

(NH4)3PO4, manufactured, phosphoric acid + ammonium hydroxide

Potassium chloride

KCl, mined

Potassium sulphate

K2SO4, mined

Calcium nitrate

Ca(NO3)2, manufactured , nitric acid + calcium hydroxide

Calcium phosphate

Ca2(PO4)3, manufactured, phosphoric acid + calcium hydroxide

Calcium sulphate

CaSO4,manufactured, sulphuric acid + calcium hydroxide