Empty plot over the winter - to cover or not

We grew forage peas and winter tares in 2 raised beds last year. In spring I chopped the stems at ground level and left the plants on top of the soil as a mulch, moving it aside when planting. This year we don't have much empty space in the beds due to garlic and overwintering brassicas, but when the chinese cabbage, kohl rabi and pak choi finishes I'll sow some forage peas again (it's probably a bit too late for winter tares).