* Luwad na may halong buhangin at humus - This literally translates to "clay mixed with sand and humus." This is the most accurate way to describe loam in Tagalog.
* Mayabong na lupa - This translates to "fertile soil," which is a general description that could be applied to loam.
* Lupa na angkop sa pagtatanim - This translates to "soil suitable for planting," which is another general description that could be applied to loam.
Ultimately, the best Tagalog phrase to use for "loam" depends on the specific context of your conversation.