Alfalfa is well adapted to a wide range of climatic and edaphic
conditions, but it does best in deep, loamy soils with porous subsoils.
It is intolerant of flooding, waterlogging, or poor soil drainage. It
requires large amounts of lime. Alfalfa does not do well on acid or
very alkaline soils, although it will tolerate some alkalinity. It has
fair salt tolerance [47,50,110]. It is naturalized to roadsides, old
fields, and waste places [37].
Alfalfa will tolerate drought and is known as a good producer in dry
years. It needs about 12 inches (30 cm) of precipitation per year on
good soils, 14 inches (36 cm) on less favorable soils [111]. Irrigation greatly enhances productivity in dry climates [50,106].