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)
Observation
- 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.
The expected answers include:
4. (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
Spacing = 30 cm x 30 cm
= 0.3 m x 0.3 m
= 0.09 m 2
Area of farmland = Length x Breadth
= 75 m x 51 m
= 3,825 m2
Plant population = Area of farmland
Spacing
= 3,825 m2
0.09 m2
= 42,500 plants
(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