Which of the following statements about the effects of agricultural techniques on the environment is true?

Fertilizer can wash off fields into nearby lakes and rivers. The added nutrients can cause algal blooms; when the algae die and decompose, oxygen in the water is consumed, potentially depleting it. Pesticides and herbicides can remain harmful even after entering water, and tillage and other agricultural practices can affect the environment.

AI-written and checked against the verified answer.