(a) ldentify specimens A, B, and C.
Specimen A: Specimen B; Specimen C;
(b) In a tabular form, compare three physical characteristics of specimens A and B.
(c) (i) Which of specimens A and B would you recommend for pond construction?
(ii) Give one reason for your answer in (c)(i).
(d) List two ways of improving specimen A for crop production.
(e) State two ways by which specimen C is of economic importance in agriculture.
Explanation
(a) identification of specimen A, B and C;
- Specimens A ; Sandy soil
- B ; Clayey soil
- C; Earthworm
(b) Physical characteristics of specimens A and B
|
Specimen A (Sandy soil) |
Specimen B (Clayey soil) |
|
It is coarse - grained It is gritty Low capillarity action High percolation rate Leaching is high It easily gets hot and cold It is not sticky when wet Low plasticity/cannot be moulded into any shape Has low water-holding capacity It is well-drained and aerated Has large pore spaces Easy to work |
It is fine grained It is smooth to the touch Capillarity is very high Percolation is low Not easily leached It does not easily get hot and cold When wet, it is highly sticky It can be moulded into any shape/high plasticity High water-holding capacity Clayey soils are poorly drained and poorly aerated Has small/fine pore spaces Difficult/heavy to work |
(c) Specimen recommended for pond construction: Specimen B/Clayey
Reason;
- Because it has very good water holding capacity
- Does not lose water through percolation easily
(d) Ways of improving specimen A (Sandy soil)
- Mulching
- Planting of cover crops/Green manuring
- Liming
- Fallowing
(e) Ways by which specimen C (Earthworm) is of economic importance in agriculture
- Helps to increase water infiltration and percolation.
- It burrows into the soil thereby helping to loosen the soil for easy root penetration.
- Helps in soil aeration.
- During feeding, the earthworms drag plant remains and leaves into the soil, thereby improving soil fertility improves crop yields.
- Helps in soil formation
- helps in mixing the soil
- It increases the organic matter content of the soil.
- Helps to improve soil structure.