Observation

This question was poorly attempted by many candidates.

 

(a) Many candidates were unable to identify the sprinkler irrigation system depicted with majority of them writing the types of irrigation systems like surface irrigation and sub-surface irrigation. Furthermore, many candidates failed to use technical terms for the important components of sprinkler irrigation. Some candidates were writing mouth in place of the nozzle.
(b) Candidates were also unable to state the advantages and disadvantages of sprinkler irrigation system as well as the effects of sprinkler irrigation on the environment. The expected answers include:
1. (a) Identification of the irrigation system - Sprinkler irrigation

 

(b) Important components of the irrigation system
- Pipe network
- Coupler
- Riser
- Pumping machine
- Nozzle

 

(c) The component which directs water into the air
- Nozzle machines fabricated locally will be less expensive      

 

  (d) Advantages of using the irrigation system
- Can be used on steep slope/undulating landscape
- Efficient control of water
- Ditches not required
- Can be used to apply liquid fertilizers
- Can be used to apply pesticides
- Small amount of water can be used economically
- Soil erosion is minimized      

 

  (e) Disadvantages of using the irrigation system
- High cost of installation
- Poor uniformity of water application during windy periods
- Pipe network obstruct the movement of farm machinery
- Requires technical know-how to operate
- Cannot be used where water supply is limited/inadequate
- Costly to maintain

 

(f) Effects of the irrigation system on the environment
- A humid environment is created in the irrigated area/microclimate
- The wet conditions encourages the breeding of pests
- Humid environment encourages the multiplication of pathogens
- Wet soil conditions promotes the growth of weeds
- May lead to pollution if it contains dangerous chemicals
- May increase soil salinity