"France produced a lot of wheat this year."

Translation: La France a produit beaucoup de blé cette année.

[knovs]

Why would they use the imperfect when there was a specific time frame given?

[ferynn]

This is not "Imparfait" but "passé composé" here : "...a produit...".
Imperfect would be "La France produisait beaucoup de blé", but you couldn't say "cette année"...