How to Enrich the Soil and Maintain Soil Fertility 

Back to: Agricultural Science Primary 4

 

Welcome to class! 

In today’s class, we will be talking about how to enrich the soil and maintain soil fertility. Enjoy the class!

How to enrich the soil

To enrich the soil means to improve on the quality of the soil so as to ensure a good or bountiful harvest. It involves methods to maintain and improve soil fertility.

Soil is said to be fertile when all the nutrients necessary for plant growth and development are present in it. Soil can lose its fertility in five main ways: burning, leaching, erosion, crop removal and clean clearing. These factors cause the soil to lose its fertility.

Causes of loss of soil fertility

1. Burning:

Burning In some places, big forests and vast grasslands are set on fire to burn. Some of these areas are good farmlands. When this is done, dead and decaying leaves, grasses and living soil organisms are burnt. Dead leaves, grasses and soil organisms add fertility to the soil. Soil, therefore, loses its fertility when they are burnt.

Activity

Mention plants and animals that will be affected when farmlands are burnt.

2. Leaching:

Leaching is the downward movement of nutrients from the topsoil to the underground layers of the soil. Some nutrients dissolve in water for plants to absorb as food. When rain falls, some water collects in low-lying areas of the farm and stays there for some time. As this water sinks into the soil, it carries with it, dissolved soil nutrients. These nutrients can no longer be available to the plants growing on the surface of the soil. The nutrients are lost or leached away.

3. Erosion:

This is the gradual wearing away of the topsoil by water or wind. When rain falls, water flows on the surface of the soil. The water carries the topsoil along with it. The topsoil contains nutrients dissolved in water. These nutrients are carried away by the flowing water and are no longer available for plants to use. Wind blows and carries some soil particles from one place to another. This soil contains some nutrients which are also carried away by the wind.

4. Crop removal:

The crops that farmers plant in their farms absorb nutrients from the soil for their growth and development. These nutrients, once taken up or absorbed, are no longer in the soil. Another crop planted in the same soil the following year may not have sufficient nutrients for its own growth and development.

5. Clean clearing:

Leaves on forest trees drop on the soil. These leaves die and decay and add nutrients to the soil. When these trees are removed and the forest undergrowth cut, the soil loses its regular supply of nutrients from the forest.

6. Over grazing:

Cattle graze on open fields and farmland being led by cattle herdsmen. Sometimes these headsmen allow the cattle to overgraze, leaving the soil bare, whereas these grasses serve as a cover for the soil. When it becomes bare it will be heated by the sun and then becomes dry, having lost most of the soil nutrients.

General evaluation

1. When is a soil said to be fertile?
2. Mention four causes of loss of soil fertility/

Assignment

1. What is erosion?
2. The downward movement of nutrient from the soil surface is called ————

 

In our next class, we will be talking more about How to Enrich the Soil and Maintain Soil Fertility.  We hope you enjoyed the class.

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