7. Secondary Nutrients?

Question 1

Sulphur (S)?

Factors reduced sulphur? (3)

Answer 1

• Reducing sulphur-containing fossil fuels usage
• Changes in manufacturing of SSP and some pesticides
• Leaching out of the root zone especially in coarse-textured soils

Question 2

Sulphur fertilizers?

Answer 2

1. Elemental sulphur (0-0-0-90 S)
2. Ammonium Sulphate (21-0-0-24 S)
3. Calcium Sulphate (Gypsum 24% S)
4. Single superphosphate (SSP) (0-20-0) (8-10% S)
5. Ammonium polysulfide (45% S)
6. Ammonium Thiosulphate (26% S)

Question 3

Calcium (Ca)?

Associated processes?
Applicable materials?
Ca deficiency in plants reasons?

Answer 3

• Liming processes.
• Gypsum
• Ca deficiency in plants is often masked by toxicity effects of other nutrients, such as:
  > Aluminum
  > Manganese
  > Copper

Question 4

Magnesium (Mg)?

Commons application?
Different salts?

Answer 4

• Applying dolomitic lime (11% Mg) or more soluble forms of Mg as MgSO4.
• Quick acting soluble salts such as Sulphates or slow acting such as Dolomitic Lime (Magnesium Carbonate).