Silage is fermenting crops under an oxygen deficiency(this is crucial to stop the crops from rotting) to preserve the gras. Its basically an upscaled version of making sauerkraut.
Easy as that.
But yeah, this devinetively isn't something everyone knows and also most people will never need this in their lives.
I don't think that at all. My family has had farms for the last four generations. The nitrogen thing is something I've actually heard, and it's a great quote for memeing.
Anaerobically fermented grass, it's cattle feed for the winter, it ferments under covers without (much) air getting to it, that way it also doesn't rot.
I think. But I'm a network engineer so that could be wrong. It's just what I think I heard in some random source I don't remember.