[PaulDavisThe1st]

There are different ways of talking about "cash crops". The sane metrics, IMO, take into consideration the inputs required and the toll that growing takes on the soil.

From this perspective, garlic is an extraordinarily excellent cash crop: high yields, very low inputs, extremely low impact on soil nutrients.

By contrast, potatoes can generate more income for the farmer per unit area per year (mostly because of the caloric density), but they do wear down soils way more than an allium like garlic, and if you take that into account, the long term picture is not so rosy.

I've read that if you can get the timing right, the most profitable crop to grow in the USA are the flowers used at high school and college graduations. The window is very narrow, however, and if you miss it you earn basically nothing at all.