Week 1 – SS2 First Term Agricultural Science Notes

FIRST TERM E-LEARNING NOTE

 SUBJECT: AGRICULTURAL SCIENCE             CLASS: SS 2

 SCHEME OF WORK

 WEEK    TOPIC
    1-2    Soil: Meaning, Types, Composition and Properties of Soil.
    3        Farm Machinery and Implements: Types, Description, Uses and Maintenance.
    4-5    Surveying and Planning of Farmstead; Meaning and Importance, Common Survey Equipment.
    6    Irrigation and Drainage; Meaning, Importance, Types, Advantages and Disadvantages.
    7     Environmental Factors Affecting Agricultural Production (Crops and Animals), Climatic Factors – Biotic factors – Edaphic factors.
    8 – 9    Plant Nutrient and Nutrient Cycle.
    Macro and Micro Nutrients.
    Nitrogen, Carbon and Water cycles.
    10     Factors Influencing Nutrient Availability in the Soil.
    Methods of Replenishing Soil Nutrients
    Farming Practices

 REFERENCE BOOK

• Essential Agricultural Science for Senior Secondary Schools, by O.A. Iwena
• Prescribed Agricultural Science for Senior Secondary Schools by S.A. Omofuyi Otal
• WAEC Pack

 
 WEEK ONE
TOPIC: SOIL
CONTENT

• Meaning of Soil
• Types of Soil
• Composition of Soil
• Properties of Soil

 MEANING OF SOIL
Soil can be defined as the unconsolidated weathered materials found in the upper most layer of the earth surface on which plants grow. It provides support and nutrients for the plants.

 TYPES OF SOIL
The three types of soil are; Sandy Soil, Clay Soil and Loamy Soil.
 A soil is said to be sandy if the proportion of sand particles in a sample of the soil is high. The particles are mainly quartz (SiO2).

 PROPERTIES OF SANDY SOIL

1. Sandy soil is coarse, grained and gritty.
2. It is loose with large pore spaces.
3. It absorbs and loses water easily.
4. It is not sticky when wet and cannot form a cast or ribbon.
5. It is well aerated with low water holding capacity.
6. Percolation in sandy soil is high but capillarity is low.
7. Sandy soil heats up easily during the day and cools down quickly in the night.
8. It supports leaching, hence it is low in plant nutrients.
9. It does not support water logging and erosion.
10. Sandy Soil has grey or brownish colour.

     METHODS OF IMPROVING SANDY SOIL
    

11. Planting of cover crops
12. Application of compost manure
13. Application of farm yard manure
14. Mulching the soil
15. Avoidance of bush burning

     ECONOMIC IMPORTANCE OF SANDY SOIL
    

16. It is good for cultivation of cassava, cotton, groundnut etc.
17. It is good for building construction when mixed with cement.

     EVALUATION
    

18. What is soil?
19. List the three types of Soil and state three characteristics of sandy soil.

     CLAY SOIL
    A soil is said to be clayed if the proportion of clay in a sample of the soil is very high.

     PROPERTIES OF CLAYED SOIL
    

20. The particles are fine, powdery and smooth when dry.
21. The parties are sticky and moody when wet.
22. The particles are tightly bound together with little pore (air) spaces.
23. It has a high water holding capacity.
24. It is poorly aerated.
25. Percolation in clay is low but capillarity is high.
26. It does not support leaching, hence it contain plant nutrients.
27. It is hard when dry and sticky when wet.
28. It can easily form a ribbon or cast when molded.
29. It supports water – logging and erosion.
30. It has a grey or brownish colour.

     METHODS OF IMPROVING CLAYED SOIL
    

31. Liming
32. Addition of organic manure

     
     EVALUATION
    

33. What is clay soil?
34. In a tabular form, give five differences between sandy and Clay soil.

     LOAMY SOIL
    Loamy soil is a mixture of sand and clay particles with high proportion of organic matter.

     PROPERTIES OF LOAMY SOIL
    

35. Loamy Soil is moist, loose with moderate sized pore space.
36. The structure breaks easily when wet and friable when dry.
37. It has non-powdery and non-sticky texture.
38. It can easily be worked or cultivated.
39. It contains lots of organic matter (humus).
40. It does not support erosion and water logging.
41. It was well aerated and it can hold water.
42. It is the best soil for cultivation of crops.
43. It is dark brown or black in colour.

     EVALUATION
    

44. What is loamy soil?
45. List four properties of loamy soil.

     COMPONENT/COMPOSITION OF THE SOIL
    The composition of the soil by percentage are:

46. Soil mineral matter        45%
47. Soil water            25%
48. Soil air                25%
49. Soil living Organisms        5%

     GENERAL EVALUATION
    

50. List two methods of improving clay soil.    
51. List the component of soil and their respective percentage composition.
52. List three ways of improving sandy soil.
53. List five properties of sandy soil.
54. List five properties of clay soil.

     READING ASSIGNMENT
    Essential Agricultural Science for Senior Secondary Schools by O.A. Iwena pages 65-87.

     WEEKEND ASSIGNMENT
    

    1. Particles of soil care closely packed together in ____ soil (a) sandy (b) clay

       (c) loamy (d) silt

    2. Quartz is the major composition of ____ soil (a) clay (b) loamy (c) sand (d) silt
    3. The soil which mostly which mostly support leaching is ____ (a) sand (b) clay

       (c) loamy (d) silt

    4. The soil which supports water logging is ____ (a) sand (b) silt (c) clay (d) loamy
    5. The best soil for agriculture is ______ (a) sand (b) clay (c) silt (d) loamy

     THEORY
    

55. (a) What is a soil?

        (b) List the four component of soil.
    2.    (a) State four characteristics of clay soil.
        (b) What is weathering?