Ultisol is comparable with alfisol except for having

Ultisols are strongly leached, acid forest soils with relatively low native fertility. They are found primarily in humid temperate and tropical areas of the world.
Alfisols are moderately leached soils that have relatively high native fertility. These are primarily found in temperate humid and subhumid regions of the world.
Alfisols have at least 35% base saturation, meaning calcium, magnesium, and potassium are relatively abundant. This is in contrast to ultisols, which are the more highly leached forest soils having less than 35% base saturation. That means Ultisol is comparable with alfisol except for having low BS% where BS is base saturation.