What term describes a pesticide that breaks down quickly in the environment?

The term that describes a pesticide that breaks down quickly in the environment is "biodegradable." This means that the pesticide is capable of being decomposed by microorganisms into simpler, non-toxic substances, allowing for a reduced environmental impact. Biodegradable pesticides are designed to minimize accumulation in soil and water, which is important for maintaining ecological balance and protecting non-target organisms.

In contrast, a persistent pesticide remains in the environment for an extended period before breaking down, potentially leading to longer-term ecological risks. The term "toxic" refers to the degree to which a substance can cause harm to living organisms, but it does not provide any specific information about how long the pesticide remains in the environment. "Systemic" describes a pesticide that is absorbed by a plant and distributed throughout its tissues, affecting pests that ingest plant parts, but again, it does not pertain to the breakdown rate in the environment.

Therefore, "biodegradable" is the accurate descriptor for pesticides that decompose quickly, helping to ensure that their environmental footprint is minimized.