If farmer renting land can decide year-to-year whether it is worth it to him to farm the land. If the renter determines that a particular lease is not profitable, he is free to do something else. The landowner has no such option; he's stuck with the land.

The renter generally pays a higher price per year than an owner but has greater options and less risk.

This is generally true of renting vs buying. If you go to distant city for a one-week vacation, you are likely to rent accommodations and a car rather than buy them. At the end of the week you can just walk away, whereas the owner must concern himself with generating an income with his property.