Farming

Farming is used to get herbs which you will use in order to train Herblore. In that way, you could say that Farming and Herblore are two skills that you can cross off the list by training Farming. You are not capable of planting anything other then herbs simply due to the fact that no one cares about any other resources. Majority of the people only train Farming in order to get herbs so that they can create potions, or in order to get the maximum level. That's why the development team has decided that adding herbs to Farming is enough.