The truck farm I worked at during my HS and collega years - we mulched about two acres every year with "salt hay" - which isn't truly salty, nor is it hay....mostly. the tidal marshes are filled with what we call "marsh grass" - but I think it is actually some type of sedge....over the winter the long stems break off and the wind and tides pile it in deep layers around the edges of the marshes. So Every spring we would load the truck up multiple times.(with pitchforks) and spread it on the fields (again, with pitchforks)   
The asparagus beds; the raspberry beds and most of the vine crops would all get a nice 6 inch layer. (That;s the cukes, the zuchinni and summer squash, the ornamental gourds) Some years the field tomatoes got mulched as well - though not the winter squash or the trellissed tomatoes.

The boss always had us spread a truckload in the greenhouse as well.