Observation

a) This question was fairly popular among the candidates. Majority of candidates were able to state the method of dispersal of the weeds listed but did not follow the scientific convention of writing botanical names thereby losing marks.

b) Many candidates were unable to give examples of physical and economic factors affecting land availability for agriculture.

c) Although, most candidates were able to enumerate the effects of pollution on agricultural lands and ponds, only few of them could state the ways of minimizing it.

The expected answers include:

2. (a) Completion of table on weeds



(b) Factors affecting land availability for agriculture

(i) Physical factors

- Soil type
- Land degradation
- Soil fertility
- Soil properties such as texture and structure
- Topography
- Soil pollution

(ii) Economic factors

- Population pressure/housing
- Expansion of industries
- Mining/mineral exploitation
- Recreation/tourism
- Transportation
- Construction of markets

(c) Effects of pollution on agricultural lands and ponds

- Death of aquatic organisms
- Loss of income/investment
- Disruption of ecological balance
- Crop failure/death
- Contamination of crops
- Contamination of water
- May increase cost of production

(d) Ways of minimizing land and pond pollution

- Controlled application of herbicides
- Controlled application of fertilizers
- Controlled application of pesticides
- Proper maintenance of oil pipelines to prevent spillage
- Adoption of organic farming
- Proper disposal of sewage
- Proper disposal of animal wastes
- Fencing of ponds