It seems that famines in China were commonplace even pre-19th century:

https://en.wikipedia.org/wiki/List_of_famines_in_China

Political system may be one of the reasons (feudalism doesn't have a great record in preventing famines either), but the most salient explanation might be that a pre-modern economy with high density of population is inherently prone to famines - a bad drought will easily topple the precarious balance between demand and supply towards lack of food, and without a railway network it is nearly impossible to move food easily among places that don't have good ports.