It was around twelve thousand years ago; a group of nomadic hunting and gathering humans started to plan ahead and sowed the seeds of some edible plants they had previously gathered in the wild, hoping to ensure a similar bounty for the year to follow.
This is called the Neolithic revolution and nothing since it has changed human society more. Being able to cultivate edible plants allowed us to stay in one location and with larger communities than ever before. Some say that the clearing of forests for farmland has even managed to stave off another ice age.
As much of an impact the invention of agriculture had on us humans, I too believe that the Farming skill had a huge impact on RuneScape itself.
Remember the prelude to it? For several weeks some NPC's could be thieved from and/or killed for seeds to be used when the skill was finally to be introduced. And while Guam, Marrentill and all the way up to Torstol seeds stacked separately in your bank, they were all simply called Herb Seeds. This made trading in these items, of which the purpose was yet unknown, a bit precarious.
And then patches were introduced along with the skill as a whole, so we could finally start weeding, composting, planting and harvesting. Since then, RuneScape as a whole changed.
But people were confused. They wanted to train Farming, but boy did it take a long time for those first Potatoes to grow. Admittedly, there was a bug on the first day that allowed you to plant and quickly dig out the seed again, gaining small amounts of experience quickly. But after that was patched, people had to go back to normal Farming as we know it today.
This wasn't all that easy. Everyone was used to getting experience by active involvement in a skill. In this respect Farming was completely unlike any other skill there had ever been before. Planting your crops and leaving to come back later is not something that was part of the average RuneScape player's normal behaviour at a time. They wanted experience, and they wanted it now!
But over time people adjusted to it. Updates such as the Tool-shed Leprechaun gave us the ability to not have to carry everything everywhere, and having him note our crops saved us many a trip to the bank. But the Farming skill reached its full potential when new Cooking recipes came out (for Pies and Potato toppings), and later the Extreme potions were added to the Herblore skill. Face it; If you want the best potions and the best food, you're going to have to turn to Farming.
So I thought this skill had it all, but I was wrong. Upon closer inspection, Farming seems to be incomplete. Allotments, by far the most abundant type of patch out there, only accept seeds that require up to level 47. Patches for Flowers and Hops tell a similar story. In fact, most of the items produced from Farming aren't used nearly so often as Herbs are.
Now, we could see an expansion on the skill, such as using the Allotment patches to farm Grapes or perhaps some variety of squash. Even cereals (rice, wheat and maize are by far the world's #1 staple food) would be a good option, but whatever food or other type of produce you come up with, the Cooking and Herblore skill are already quite saturated.
Plenty of suggestions have been offered to include animals into the skill, and this certainly would take away that "gardening" feeling. Chickens, cows, sheep, goats, pigs or even bees could be kept for their typical yields, but for the skill to be truly like Farming you'd have to think differently.
Although I doubt we'll see things like crop rotation, soil composition, sunlight depending on your latitude, or even seasonal plants become part of the skill, there are a few fields that Farming can still expand in.
Fibres such as hemp, flax, cotton or silk may provide raw materials to make a multitude of clothes. Making robes and other potentially magical clothing has often been speculated to be a future skill known as Tailoring, but could just as easily fill the high level gap in Crafting.
Or what about Aquaculture? Some people can't stand the tedious hours wasted away at the waterline hoping to catch something and level the Fishing skill. Imagine if you could grow and harvest shrimp or carp in designated enclosures. The once-off chunk of XP that you'd normally get from harvesting your crops would now go partly to your fishy needs, and could be the perfect way to level up without nodding off at your computer.
The things we humans have learned to grow and harvest under controlled conditions are both diverse and plentiful, leaving the Farming skill with plenty of areas to expand into. I think you'll agree with me that, while thus far Farming has been a dark horse skill, future additions to it do not need to be in the typical fields it so far has put down its roots.