Fertilisers & Eutrophication

What Are Fertilisers?

Fertilisers are substances added to soil to supply essential nutrients for plant growth. They can be natural (organic) or artificial (inorganic).

• Organic Fertilisers: Derived from plant or animal matter, such as compost or manure.
• Inorganic Fertilisers: Manufactured chemicals containing nutrients like nitrogen, phosphorus, and potassium.

How Do Fertilisers Impact the Environment?

While fertilisers boost plant growth, they can also have negative environmental impacts:

• Runoff: Excess fertiliser can wash into water bodies, leading to pollution.
• Soil Degradation: Overuse of fertilisers can alter soil pH and reduce soil fertility over time.

Understanding Eutrophication

Eutrophication is the process where water bodies become overly enriched with nutrients, leading to excessive growth of algae and other aquatic plants.

Stages of Eutrophication

1. Nutrient Enrichment: Nutrients from fertilisers enter water bodies.
2. Algal Bloom: Rapid growth of algae due to excess nutrients.
3. Oxygen Depletion: Decomposing algae consume oxygen, reducing availability for other aquatic life.
4. Death of Aquatic Life: Low oxygen levels can lead to the death of fish and other organisms.

Examples of Eutrophication

A common example of eutrophication is the "dead zones" in the Gulf of Mexico, where nutrient runoff from the Mississippi River has led to significant oxygen depletion.