You answer:

Yet another classic case where you should be asking if before you ask why. Canada is by far and away a net exporter of food. The Canadian Prairie provinces have long been known as the bread basket of the world because of the amount of wheat produced and exported from there. In addition to grains Canada also exports large amounts of meat, fruit and other food products. Really the only things that Canada imports a lot of are tropical type fruits and vegetables that can't be grown here.