NOTE: This suggestion is extensive and comprehensive because farming in most games is, well, not something you consider a skill. Anyone can farm in games, and that's always been the case. I mean, look at Don't Starve, or Minecraft, or any of the dozens of games that actually have the word
farm in their names. There is no challenge in virtual agriculture, and certainly nothing to master. This is as comprehensive as a system like this can be without being impossible to learn. Everything in this suggestion is possible using medieval tools. It is recommended that this suggestion is read thoroughly and completely. Better bring a snack too, because this is a long one.
So we know gems will have different qualities, and so will craftable items... but what of farmable goods? I got thinking about this because of a scene in The Witcher 3, where a peasant delivered a cut of his crops to an invading king, but one bushel was rotten.
Now, I'm not saying to make everything rot. Rather, instead of growing carrots, you either grow super healthy carrots, healthy carrots, or not-so-healthy carrots... if you want to be general about it. Growing barley under perfect conditions may allow you to distill the finest, most expensive liqours, while a less specialized farmer that grows three other things may have to drink their own poison just to get rid of it.
SOILThere are several things that contribute to a plant's success in life, including light levels, temperature, soil composition and PH, and moisture, to name the most omnipresent. Unlike what Minecraft would have you believe, you can't grow wheat in the middle of a swamp because A. The soil is like battery acid compared to a plain, B. The overabundance of moisture would cause it to rot from the roots up in less than a week, and C. Low light conditions would starve the plant even if the root rot doesn't. By that same precedent, you can't grow a watermelon in a tundra because A. It will be growing frostymelons, B. The soil is too hard for it to take root, and C. Tundra soil is practically devoid of nutrients, and watermelons aren't exactly frugal.
What's great about this is that three elements, temperature, light and moisture/humidity are planned or implemented already; so only checks have to be performed there. Soil composition and PH are a bit tougher, though.
While there is a good base composition for each biome, an area's soil can be greatly influenced by even a minute change. For instance, the soil under a rotting carcass should become more acidic, but richer and darker. While this may seem like a fairly insignificant feature... look back at dirt in Minecraft. I hate having to make a comparison like this... but I think we all know dirt is a joke there. It is not coveted, nor valued. It's almost an icon of shame. With the following system in place, though, quality soil exists, and may even be something people pay handsomely for so they get a better turnout. It also means that farmers in a tundra or desert may consider importing soils more suitable for growing their crops of choice, and exporting their own specialized soil to farmers or distributors elsewhere. Call it a 'dirt market', if you will.
Now, I know what is on your mind here... If soil quality at this level is implemented, there is an issue of stacking. A simple solution would be by creating a way to "blend" different soils to create a happy medium between two types of soils; any soil that is 'close enough' should just be automatically blended with an existing compatible stack. This blending also allows the desert farmers to stretch their black gold that much farther by mixing in a little sand.
Soil composition has two parts; texture and nutrients . Let's start with
TEXTURE. Texture just means particle size, in this case... there is an immense difference between a clay based soil and a more silty or gravelly soil in terms of arability. Depending on the plant you wish to cultivate, clay soil may be a kiss of death; likewise, for another plant, a silty or gravelly soil may tear the root system to shreds. Blending the two soils may create a compromise that allows for both plants to survive in the same location, however. In a perfect world, soil texture would be a three tiered attribute between sand, clay, and silt... but 'particle size' is what matters.
Here's an infographic anyway:
Now,
nutrient balances are a little more complex... and definitely more fun. That's not to say that nutrient balancing is difficult to develop or master; it's not difficult because there are distinct soil traits and plant symptoms to help identify deficiencies or harmful excesses.
There are five major nutrients that are outlined in the article linked in the above paragraph. Deficiencies and excesses of most of these nutrients have distinct symptoms that were recognizable (and treatable by some) even in the dark ages. They will be addressed below in terms of their possible in game effects(And yes, I know people wouldn't be addressing the elements themselves when they remedy the deficiencies):
Nitrogen: Can be obtained from urine... Without this, you don't have plants. It's about as important as carbon. Slow growth or no growth liikely means low or depleted nitrogen if there are no other symptoms. Too much nitrogen will cause it to leach out of and acidify the soil, which is especially true of a urine based nitrogen source; this lowers PH, generally.
Phosphorous: Can be obtained from manure... lovely. Without this, a plant is less able to harness sunlight. Initial growth will be normal, but growth and maturation will slow to a crawl once the seed's nutrients are depleted. Alkaline and acidic soils both cause the phosphorous to react with other minerals, making it insoluble in those conditions. No effect on PH.
Potassium: Obtained from potash. Aids in disease resistance and general resilience. Deficiencies may decrease fruiting and fruit size/quality. Too much is not toxic, but causes a penalty to all other nutrients. Depending on the plant the potash is made from, it may raise or lower soil PH.
Calcium: Obtained from lime(stone). Helps with development of roots and leaves. Calcium deficiency causes necrosis, curled leaves, and stunted growth. Too much calcium penalizes phosphorous, potassium, and magnesium. Increases soil PH.
Magnesium: Obtained from magnesite. Essential element in chlorophyll. Deficiency causes yellowing of leaves followed by necrosis. Increases soil PH.
PH EffectsPH effects based on penalties to nutrient uptake. High penalty means low uptake.
High PH(7.5-8): High nitrogen penalty, Medium phosphorous penalty, low magnesium penalty
Med PH(6-7.5): Low nitrogen penalty
Low PH(5-6): Medium phosphorous penalty, medium potassium penalty, medium magnesium penalty
Now that that is out of the way, I want to briefly highlight direct PH control. You can spread some lemon juice to lower ph; and use limestone or coal tar to raise PH. PH testing can be performed using litmus paper(Don't worry, litmus paper was in use back in 1300 AD!).
Nutrient dense soils will have a darker hue while lighter soils will be more and more nutrient deficient. Darker soils will be found in jungles, forests, and swamps, while lighter soils will be found in tundras, deserts, and plains.
PLANTSSurvival of the fittest, adaptations, yadda, yadda, yadda... Plants do that stuff.
Remember when I said people shouldn't just be growing carrots and barley, but great carrots, or good carrots, or nasty carrots? Well, to keep things fair, perhaps having traits for the plants as well may help alleviate the troubles of the farmers braving arid wastelands, and those migrating to swampier pastures. Perhaps wild plants should each generate with their own specific traits to give them an advantage in certain climates and soils. By isolating these differently adapted breeds, a skilled botanist can distribute plants that are adapted to otherwise inhospitable climates... or plants that grow larger and faster... or a florist could reap the benefits of crossbreeding different colors of flowers to create entirely new varieties.
