(a) (i) Describe the physical properties of each of Specimens B (SAND), C (CLAY), and D (LOAM)
(ii) To about 10ml each of the specimens B, C and D, add about 5ml of specimen O and using the hand, mix well. Describe the physical properties of each specimen?
(b) Which of the specimens B, C, and D should be considered of greater value to farmers? Give two reasons for your answers
(c) State three ways of improving each of the other two specimens not mentioned in (b) above
Explanation
(a)(i) Physical properties (before wetting) of Specimen B Sand:
- It consists of coarse and fine particles.
- It is light grey as well as light brown in colour.
- The grains are separate and do not stick together, they are loosely or Closely packed.
- It has good pore spaces and are well aerated,
Specimen C is Clay and the physical properties are as follows:
- It consists of very small and fine particles closely packed together
- Its colours may be light brown or yellowish-brown as well as straw-coloured.
- Most clay can be powdery, smooth or velvety.
Specimen D is Loam:
- It contains the presence of humus and organic matter.
- The colours are dark brown, black and greyish black.
- Loamy soil is always friable and consistent.
- Its particles are loosely packed.
- It has moderate pore spaces.
(ii) Physical properties after wetting of Specimen B is Sand:
- Most sandy soil are always gritty after wetting
- It cannot be moulded and is not plastic
- It is easily permeable to water and very porous.
Specimen C is Clay;
- Clay soil are sticky after wetting
- It can easily be moulded into plastic.
- It is not permeable to water and has low porosity.
Specimen D is Loam;
- Loamy soil is partially sticky after wetting.
- Loamy soil moulds but breaks when an attempt to form a ring is made.
- Loamy soil is moderately porous after wetting.
(b) Specimen D is Loamy soil is of greatest value to farmers: Reason:
- It has a moderate water retention capacity.
- It also has a higher proportion of organic matter.
- Most loamy soil is adequately aerated.
- They are also moderately porous.
- It has high capillarity.
- it is rich in plant nutrients
- Loamy soil is rich in soil microbes.
(c) Ways of improving specimen B Sand:
- Áddition of organic matter to sandy soil can improve its content.
- Application of lime to sandy soil can restore its content.
- Constant application of irrigation can improve sandy soil.
- Application of clay to sandy sol can improve its contents.
- The practice of fallow can improve sandy soil.
- Sandy soil can be improved by planting cover crops in the farm.
- Application of inorganic fertilizers can also improve sandy soil.
- Mulching restores the soil's fertility and ensures a good yield.
Ways of Improving Specimen C:
- Clay soil can be improved by the addition of organic matter.
- It can further be improved by the application of lime
- Drainage of excess water from the soil can improve clay soil.
- An introduction of sandy soil can improve clay soil
- Practising fallow farming for sometime can improve the clay soil.