Answer: Control the use of fertilizers.
Step-by-step explanation:
The fertilizers are the chemical or biological formulations which contains necessary inorganic and organic minerals which a soil generally lacks but required by the plants for proper growth and crop production.
The increase in use of fertilizers can cause pollution of land and water. Due to surface runoff the minerals present in the fertilizers are added to the neighboring water body which results in excess growth of plants and algea due to availability of nourishment. This phenomena is called as eutrophication.
Therefore, the use of fertilizers should be in control amounts so that it cannot cause eutrophication.