Question 2
(a) State six differences between specimens E and G. [6 marks]
(b) (i) State the major plant nutrient element supplied by specimen E to the soil. [1 mark]
(ii) Name three other fertilizers that could supply the major plant nutrient element mentioned in 2(b)(i) to the soil. [3 marks]
(c) State five disadvantages of using specimen E in crop production. [5 marks]
Candidates’ responses to Question 2 was below average.
(a) Many candidates could not state the differences between urea fertilizer and poultry manure;
(b) Many candidates listed varied nutrients as those that are supplied by urea to the soil instead of the major nutrient (Nitrogen);
(c) Most candidates could only mention NPK as the fertilizer that could supply nitrogen to the soil;
(d) Most candidates were unable to state the disadvantages of using urea in crop production.
Observation
The expected answers include:
2. (a) Differences between specimens E (Urea fertilizer) and G (Poultry manure)
Specimen E (Urea fertilizer) |
Specimen G (Poultry manure) |
- Grey/brown colour/whitish colour |
- Dark brown/black colour |
- Inorganic fertilizer/chemically |
- Organic fertilizer/of animal origin |
- Granular structure |
- Amorphous in nature |
- Contains only one element i.e. |
- Contains many elements/variable |
- Has known /fixed nutrient |
- Has variable nutrient composition |
- Requires high skills to apply |
- Requires low skill to apply |
- Nutrient is readily available to |
- Nutrient is not readily available to |
- Microorganisms are not present |
- Contains high amount of |
- Does not improve soil structure |
- Improve soil structure |
- Odourless |
- Has an offensive odour |
- Non-bulky |
- It is bulky |
- Expensive |
- Relatively cheap |
- Can leach easily |
- Cannot leach easily |
(b) (i) Major plant nutrient element supplied by specimen E (Urea fertilizer) to the soil
- Nitrogen
(ii) Other fertilizers that could supply the major plant nutrient in specimen E (Urea) to the soil
- NPK fertilizer
- Di-ammonium phosphate (DAP)/Ammonium phosphate
- Calcium ammonium nitrate (CAN)
- Sulphate of ammonia
- Ammonia liquor
- Anhydrous ammonia
- Ammonium nitrate
- Sodium nitrate
(c) Disadvantages of using specimen E (Urea fertilizer) in crop production
- Leaves acidic residues in the soil
- High technical know-how is required to apply it
- Expensive to procure
- Easily leached/eroded from the soil
- Could pollute agricultural land and water bodies
- It is toxic to human health
- Could destroy soil microbes
- Could cause crop injury if not properly applied