I've upgraded the pastry expansion on my bakery to level 5 out of 10. It's supposed to reduce crop consumption, it's done nothing, no effect whatsoever.
Look at your consumption values in the Farm. You may be building troops at the same time you reduce consumption rates.
In the Farm stats, you can see the benefit of each crop related resource. The last one in my view is for the reduction of crop use based on the level of the pastry.
Check it out.