Farming Fertilizer Guide

[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!

[Sevenless]

Honestly, if you're using coal or lime on a field I think you're spending a lot more effort that could easily be achieved by just having more fields. Only exception being if you've got a fully tiered field like Sea Island Cotton. Also remember that using 1.00p fertilizers will slow/stop/reverse your purity grinding as of current.

Don't get me wrong, great work here. Our methods just differ.

[Timeslice]

Honestly, if you're using coal or lime on a field I think you're spending a lot more effort that could easily be achieved by just having more fields.

Thanks for the tip. I guess it really depends on how much you play. The first week I played Salem I put in about 100 hours. When you play that much you have plenty of time to get fertilizer while you're waiting for stuff to grow. This is my guide to farming my way, alternate perspectives are encouraged. This also explains why I find I need 12 coal clamps for only one smelter...

[staxjax]

I dont really understand the emphasis you put on using coal, not to mention that any 0% pure fertilizers will completely negate any chances you might have for good purity increases. I'd rather make more fields and offset them to harvest every day if I was going for 'speed'. I use this same theory for plenty as well, since I can just make more fields to get as much as I want every day. When it comes to higher tier crops, that is when I will use lime to maximize the plenty to get as much product as possible out of one harvest.

[Timeslice]

I dont really understand the emphasis you put on using coal, not to mention that any 0% pure fertilizers will completely negate any chances you might have for good purity increases. I'd rather make more fields and offset them to harvest every day if I was going for 'speed'. I use this same theory for plenty as well, since I can just make more fields to get as much as I want every day. When it comes to higher tier crops, that is when I will use lime to maximize the plenty to get as much product as possible out of one harvest.

I haven't started purity grinding yet, so this is all news to me. So using 1.00p doesn't reduce purity, it only eliminates the changes for purity increase? So after you get a 20% pure tier four crop it doesn't matter which fertilizer you use?

[staxjax]

P1 fertilizers calculate into the random purity modifier some way or another, I just know if you use p1 fertilizer on fields it will raise the elements you dont want and lower the one you do want. With enough fertilizer you could drop a 20% pure field to 0% pure.

If you don't use any fertilizer at all, the harvested product will have a chance to increase or decrease in purity...after awhile, with enough of the same element, you will (hopefully) only see increases.

I would use humus from composting higher purity same kind cereal seeds for plenty on higher tier crops.

[Sevenless]

I'm not certain of the exact mechanic (loftar thought it didn't influence at all, but there was something slipped into the code in such a way that it does influence purity) but putting in high purity dross will speed up purity in that element, and 1.00purity will reduce purity in the highest element. This is mixed with a random factor such that you don't see it at low purity but late it'll massively slow the speed at which you gain purity. Up to a point where it'll be impossible to gain at all.

Tiers and Purity aren't related at all. Because you need to mass use P1 fertilizer to get tiers up, it's best to do that with **** seeds while keeping your purity seeds on a seperate field.

Thanks for the tip. I guess it really depends on how much you play.

Read what I said. Instead of using fertilizers, just plant more fields. I use 4 fertilizers per field I plant, and have about 100 fields on the go right now (this isn't much more than 1hr per day worth of farming using my method). Because you're getting the benefit of maxed power fertilizers, and you're getting more uses of your S/C bonus (since each field planted gets an additional plenty bonus from your character). Per time spent, you're getting more out of it than if you use 10-20 fertilizers per field.

[MagicManICT]

Yep. Why waste fertilizers on one field? Laws of diminishing returns dictate less is really more. It's just up to each player to determine the amount of time they have to manage a field vs gathering materials to fertilize it with. The only thing is that more fields means more wood choppings to keep the upkeep down. With three-field system, you don't even need much (if any) in influence to maintain a tier.

[Sevenless]

With enough S/C, you can forgo even the wood chipping actually. Farm purely off the seed production for humus and the starter seeds required. Likely you'd need at least 200-400 S/C to do that and still see meaningful production of crops. But you could purity grind all the way to 10 that way.

[Potjeh]

Hay is *the* influence fertilizer, can't get serious about higher tiers without lots of it. So what you should do is plant a ridiculous amount of cereals to get lots of hay, and just use all the excess seeds to fill compost bins.