Question 4
(a) State six advantages of organic fertilizers over inorganic fertilizers. (6 marks)
(b) If the spacing of tomato is 30 cm x 30 cm, determine the population of tomato plants expected on a farmland measuring 75 m x 51 m. (6 marks)
(c) (i) What are ornamental plants? (2 marks)
(ii) Mention four maintenance practices that are carried out on ornamental plants. (4 marks)
- Some candidates misconstrue Question 4(a) and tabulated the differences between organic and inorganic fertilizers.
- Question 3(b) was poorly attempted as majority of the candidates could not determine expected plant population of tomato on the farmland.
- Question 3(c) was popular among candidates and responses were above average.
Observation
The expected answers include:
- (a) Advantages of organic fertilizers over inorganic fertilizers
- Not easily leached in the soil
- Improve soil structure
- Supply more nutrients than inorganic fertilizers
- Relatively cheaper than inorganic fertilizers
- Nutrients in organic fertilizers are not volatile and could not be lost
in hot weather in form of gases
- Organic fertilizers do not make the soil to be acidic/have buffering
effect on the soil
- Promote the activities of soil microorganisms
- Increase soil microbial population
- Helps to regulate soil temperature
- Have longer effect on the soil
- Readily available
- Nutrients are slowly released to the soil
(b) Determination of population of tomato plants expected on farmland
(c) (i) Meaning of ornamental plants
Ornamental plants are plants that are grown to decorate/beautify the
environment/ grown for their aesthetic value
(ii) Maintenance practices that are carried out on ornamental plants
- Shading - Watering/ irrigation
- Weeding - Pruning/ trimming
- Fencing - Fertilizer application/organic manuring
- Thinning - Supplying