Pasture
Grass
noun
The pasture grass is the pasture and grass.
ぼくそう
With 草 you learned a different reading from the one here. Just think about how with this pasture you have to constantly sew (そう) it together to make it come together, otherwise it comes apart and moves all around, and that's no good for any pasture.
氷点下の日々が続いているせいで、牧草が全てやられてしまった。
It has been below freezing for days, so all my grass is dead.