You don't say what kind of grass.  I am going to presume it is perennial forage grass, not an annual grass (weedy grass).

There is value in rotating to a non-grass crop, after a grass. So, I would lean towards the peas or canola.

However, I have seen guys kill down timothy/orchardgrass sods in late summer (August) and no-till in winter barley or winter wheat.  If you watch your fertility, it can work.