Which type of herbicide is known for acting quickly and not persisting in the soil?

Nonresidual herbicides are designed to act quickly on target weeds and do not persist in the soil after application. This characteristic makes them particularly useful for quick control of annual weeds or for managing specific weed outbreaks without leaving harmful residues that could impact subsequent crops or vegetation.

These herbicides typically work by directly affecting the physiological processes of the weeds upon contact, leading to their rapid demise. Because they break down quickly in the environment, they do not pose a long-term risk to subsequent plantings and can be safely used in diverse agricultural or landscape settings.

In contrast, other types of herbicides, such as systemic or residual herbicides, may work differently, either by being absorbed into the plant's system and affecting it over time, or by remaining active in the soil for extended periods, making their use more complex in crop rotations or sensitive landscapes. Contact herbicides, while acting quickly like nonresidual ones, may not have the same low persistence in the environment, thus making nonresidual herbicides the best choice for immediate and temporary weed control.