The crop failing message is usually an indicator that your farms are not being worked. The exact reason for that can vary - lack of employees, water shortage, electricity shortage, these kinds of things.
As said above, if your food situation is critical, increase the priority of the farm to make sure it is supplied and worked above everything else.
As said above, if your food situation is critical, increase the priority of the farm to make sure it is supplied and worked above everything else.