- Fertilizers are the nutrients that are made by man and provided to the crops.

- Many types of nutrients are manufactured by man.

- When only one type of nutrient is used as a fertilizer, the product is known as straight fertilizer.

- When more than one nutrient are mixed or combined to form a fertilizer, the product is known as a compound fertilizer.

Fertilizers can be applied onto crops in various ways for example:

  1. Digging holes in soil and placing solid fertilizers in them together with the seeds.

  2. Liquid fertilizers can be sprayed on the plant.

This method is called foliar application.

The fertilizer can be dissolved in water, then the water is used to water the plant.

Below is an illustration of how foliar application is done:

  3. The fertilizer can also be applied as topdressing in that the fertilizer is applied around the stem of the plant.

The table below contains commonly used fertilizers and the nutrients they contain:  

Advantages of using fertilizers 

• Increases soil fertility
• Increases crop yield
• Have many nutrients
• Increases rate of growth
• Specific fertilizers are applied for specific deficiencies.

Disadvantages of using fertilizers 

• Difficult to apply
• Often pollute water, air and soil
• Some have harmful effects to plants and even when applied in excess
• Requires a lot of labour
• Often expensive
• Not easily available
• May have side effects to farmers and livestock
• Poisonous if crops are harvested and eaten soon after spraying.