Pls !

which of the following agricultural practices can lead to algal blooms? select the two correct answers.
- sediments released by tilling of soil
- withdrawls of water for crop irrigation
- animal waste accumulated in livestock production
- application of nutrients to crops
- erosion caused by livestock overgrazing

The agricultural practices can lead to algal blooms are:

Explanation:

Unsustainable agricultural practices and livestock production leads to an algal bloom. Algal blooms are mainly caused due to eutrophication of water bodies like lakes, rivers, streams, ponds, seas etc with an increase of nutrients like phosphorous and nitrogen.

Nutrients like phosphorus and nitrogen are present in large amounts in fertilizers (NPK fertilizers) or manure applied to the crops, excess of which settles on the ground.

Animal wastes contain ammonia and other nitrogenous compounds. Improper waste management in livestock production leads to the accumulation of these wastes.

When it rains, these soil nutrients and accumulated animal wastes runoff and get carried and washed away by the flowing water and reach these water bodies. The water bodies get highly enriched with these nutrients which lead to eutrophication and algal blooms.