No, if you expect farmland to produce 0 food then having extra farmland is pointless. 0 * 2 X = 0 * X = 0.

The point of extra farmland is to make up for some expected shortfall, but you’re better off stockpiling food during productive periods than have reserve capacity for use when something else is going wrong.

PS: It is common to have quite large stockpiles of food. Many crops come in once a year and then get used up over that year. But that assumes a 1:1 match between production and consumption, a little extra production = quite a large surplus in a year.