I was under the impression that there was a lot of agricultural land under cultivation in Korea, so much that some farmers are experimenting with growing what are, for the area, exotic foreign vegetables.
For instance, if Wikipedia is to be believed, in Korea there is currently a fad for the type of broccoli cultivated in Europe and North America, which has historically not been a part of Korean cuisine. Supposedly it is very lucrative. Farmers get good prices for this crop.
I imagine that if they wanted a larger cattle industry they could have one. If the people want the meat, in a free market this will attract more farmers into that area to supply the demand, because it will be profitable.
Then, too, many nations trade in food. This has always been the case. The US exports soybeans, grain, and beef, for example, and imports oil and manufactured goods. Why not, if this is beneficial to all participants?