8th July 2020 nfeditor

JSS 2 : AGRICULTURAL SCIENCE : WEEK 2

NEW APPROACH

TERM/WEEK: THIRD TERM/WEEK 2

DATE: 4th July, 2020

CLASS: J.S.S 2

SUBJECT: Agricultural Science

TOPIC: Soil

Reference:

BRIEF EXPLANATION: Agriculture is practice on land which is the resource of man. The land is used for cultivation of crops and rearing of animal. Soil is the component of that portion of land that supports the growth of crops and provides the food (nutrients) which the crop takes in and use for their growth and production of food. Soils vary from place to place and one form to another. This topic discusses the meaning, types and properties of soil.

NOTES FOR THE STUDENTS:

DEFINITION OF SOIL:

Soil can be defined as a medium on which plants grow on the uppermost layers of the earth’s crust.

TYPES OF SOIL AND PROPERTIES:

Soil is made up of particles. These particles may be very small, quite big, or a mixture of different sizes of particles in various proportions. This is what gives different soils their completely different properties.

CLASSIFICATION OF SOIL BASED ON PROPERTIES AND CHARACTERISTICS OF THE PARTICLES

  1. Sandy soil
  2. Silt
  3. Clay soil
  4. Loamy soil

SANDY SOIL: The particles are coarse gritty to the touch, large enough to be seen with the naked eye. They are loose and have large air spaces. They are well drained, easy to work and nutrient leash out easily. It has up to 70% sand.

SILT: They are smooth, powdery and has large surface area .They are slightly sticky.

CLAY SOIL: Clay particles are fine and very tiny. They are sticky when moisten with water and could be molded into shapes. Clay soil holds water and excludes air. It is poorly drained and waterlogged. It is heavy to work on but rich in nutrients. It has 40%  or more clay.

LOAMY SOIL: Loamy soil has roughly equal proportion of sand silt and clay. It is crumbly to the touch, has good air spaces and drainage. It is rich in nutrients. Loamy soils combines the good physical properties of sand and the good properties of clay. It is therefore the best soil for agriculture.

SOIL STRUCTURE

Soil structure refers to the grouping or arrangement of soil particles in aggregate of varying consistency or the physical appearance of the soil according to the way individual particles are packed. Soil structure has a relationship with air, water , and mineral component of the soil.

EXERCISE/ASSIGNMENT

  1. Define soil.
  2. List four types of soil.
  3. Define soil structure.