Under which condition would nutrients typically move most quickly to groundwater?

Nutrients typically move most quickly to groundwater when they are applied during a heavy rain event. This is because heavy rain can lead to increased surface runoff and rapid infiltration, resulting in nutrients being transported beyond the root zone of the plants directly into the groundwater.

In contrast, when nutrients are applied all at once while plants are very small, the limited root system cannot effectively absorb these nutrients, but this scenario does not inherently lead to a quick movement of nutrients to groundwater. Nutrients applied at high rates may exceed plant uptake capabilities, but again, this does not ensure rapid movement to groundwater unless facilitated by other factors, like heavy rainfall. When plants are at full growth, they typically utilize more nutrients, reducing the likelihood that excess nutrients will leach into the groundwater. Therefore, heavy rain represents a critical condition that accelerates nutrient transport to groundwater.