Interesting, I thought the N would be stored in the little nodules on the roots? For other legumes you're supposed to cut them of, not pull them out, so that the roots with their nodules remain and release the N during the rotting process. Is this bullshit?

When clover is mowed and the clippings mulched back into the soil, the decomposition of the leaves adds nitrogen to the soil. If you remove the clippings the nitrogen goes with it.

Yes, "green manure" is taking nitrogen fixing crops (like clover and beans and peanuts) and to mulch them while still green, and incorporate that decomposing mulch into the soil you're using. That adds nitrogen in fewer steps than the traditional way of using animal manure (where the nitrogen still ultimately comes from plants).

Of course, the modern Haber process also fixes nitrogen through industrial chemistry rather than agriculture, so most commercial fertilizer today gets its nitrogen from chemical synthesis of atmospheric nitrogen into ammonia.

50°F = 10°C
95°F = 35°C

Oh, and it's super satisfying to walk on in barefeet

Unless you happen upon one of those bees.