Salem Farming Fertilizer Guide

Salem Farming Fertilizer Guide by Timeslice

After searching the forums for a comprehensive guide to fertilizer and finding nothing, I’ve decided to write the guide I wish I had when I started farming.
For most of my fields I shoot for 200% Plenty, 200% speed, and 50% upkeep, although higher plenty and speed are possible. Note that the order of fertilizers is very important!

New Fields

When you till a new field it starts off with 100% upkeep, meaning it takes 5 humus, and 100% of the normal amount of seed to plant it. For a fresh field the objective is to lower the upkeep so that your next planting costs you less resources.

Your first field

With your first field you probably have just enough seeds to plant one field, and want to maximize your return wile minimizing your expense. For this I like to use:
10 wood chippings, then 10 lime.
This gives me:
Upkeep: 50%
Plenty: +102.97%

If I want to acheive my speed goal it would require 23 coal which would give +103.38% Speed, but that’s usually way more coal than you would want to spend on your first field.

Additional fields

For additional starter fields I’m just looking to crank out a 50% upkeep field as fast as I can as cheaply as I can, so I’ll use my most abundant low cost seed (cereal in my case) and dross instead of coal, using:
10 wood, then 22+ dross
Note that you may be able to use more than 22 dross depending on how much random bonus plenty you recieve on planting the seeds, as you cannot drop your plenty (or any stat) below 50%
This gives me:
Plenty: 50.79% (or so) Note this is not +50%
Speed: +49.21% (or more)

Maintaining Fields

These are fields that have already gone through one cycle and are at roughly 55% upkeep. At this point you want to maintain the upkeep at 50% and boost your yield and speed. This takes wood, lime, and coal. Depending on whether you find lime or coal more precious, you have two options:

Minimize lime usage
4 lime, then 12 coal, then 3 wood choppings
This gives:
Plenty: +111.38%
Speed: +103.05%

Minimize coal usage
7 coal, then 9 lime, then 3 wood choppings
Which gives:
Plenty: +105.84%
Speed: +100.45%

You may notice that the Upkeep will probably show 50% at just 2 wood choppings, but it will actually be somewhere around 50.5%. It’s up to you to decide if you care or not.

Improving Fields

Once you’ve built up a stock of crops you’ll probably want to start working towards the higher tier crops. This will involve increasing the Influence and rotating your crops. Refer to the wiki for the recommended crop rotations for a desired target crop. I use humus to raise my influence because it’s so easy to obtain, but you could alternatively use hay with potentially better results (base of +40% on first use), but hay is such a pain to get (although you get one with each cereal harvest) that I don’t cover it’s use. Again, depending on whether you find lime or coal more annoying to get you have two options:

Minimize lime usage
10 humus, then 3 lime, then 19 coal, then 3 wood choppings
Which provides:
Plenty: +110.02%
Speed: +101.32%
Influence: +100.42%

Minimize coal usage
10 humus, then 17 coal, then 4 lime, 3 wood choppings
Granting:
Plenty: +105.30%
Speed: +103.27%
Influence: +100.42%

Note that this is an awful lot of coal to be dumping into a field, so you may want to consider just waiting. Then again, if you’re in no hurry then I suggest also adding clay which is easy to obtain and will improve the influence at the cost of speed. I’m not that patient, so I’ve never used clay and can’t give you any concrete numbers on its use.

Conclusion

I hope this helps people to avoid wasting the time and resources I spent trying to figure this stuff out on my own. Let me know if you have any questions or suggestions on improvement. There are a few things I could use information on:
Crown Manure: If money is no object, this seems like a great way for the lazy man to fertilize. However, at 250 silver a bag I’d like to know whether it’s 10 uses or 30 before I buy it (the wiki is ambiguous).
Turkey Droppings: I’ve never had a turkey coop, so I haven’t tried this, but the stated 5 speed/24 influence doesn’t seem like anything to write home about to me.
Three-field System: I don’t have this skill (yet), so I can’t comment on it’s effect. If anyone has this and would be willing to do some science, I would definitely appreciate it!

Math used:

To calculate the effect of a fertilizer the game uses the formula <base value>/sqrt(use). For example lime is 40/sqrt(x), so +40% if used as the first fertilizer, +28.28% if used as the second, etc. The game displays rounded values, but stores everything internally at much greater precision.

Thanks for reading!