Alfalfa is a tough perennial with established rooting depths down eight feet or more. Depending on deep soil profile moisture, some varieties can extend spring dormancy and survive up to 45 days without rainfall. However, forage yields drop dramatically, since alfalfa requires about six inches of root available water to produce one ton of forage per acre.

Read the full article at: https://cropwatch.unl.edu/2024/pasture-and-forage-minute-early-season-irrigation-controlling-alfalfa-weevil