Crop Quality on standard soil?

[Moiraimancer]

Does anyone know the chance to harvest quality crops on standard, unfertilized soil?
I've been searching around on Google, the wiki, and a few pages of the discussion forums here, but I haven't been able to find anything about it.
For example, with Basic Fertilizer, you supposedly have a 33% chance of getting a silver quality crop and a 33% chance of getting a gold quality crop.
I want the info for a spreadsheet I'm collaborating on with a friend.
Even some rough estimates would be helpful.

[Moiraimancer]

I did some quick testing of my own so I'd have some data to back up my numbers, I planted 100 parsnips 6 times (total 600 parsnips) and here are the numbers I got:

Harvest 1: 18 gold, 37 silver, 45 normal
Harvest 2: 22 gold, 38 silver, 40 normal
Harvest 3: 22 gold, 34 silver, 44 normal
Harvest 4: 19 gold, 30 silver, 51 normal
Harvest 5: 19 gold, 29 silver, 52 normal
Harvest 6: 22 gold, 33 silver, 45 normal

Total: 122 gold, 201 silver, 277 normal (600 total)
So, with those numbers, we have a 20.3% chance of gold (most likely actually 20%, or 1/5), a 33.5% chance of silver (most likely 33.3, or 1/3) leaving us with a 46.16% chance of getting a standard crop (most likely 46.66%, or 7/15).
I'm at level 10 farming, I have no idea if that influences crop quality. If it does, at least max level makes for a solid place to test these numbers.

[Amicus]

Farming level does effect crop quality chances. The figures I have seen for 10 farming (think people looked into the code and worked it out) was 21% gold 42% silver. So your testing was pretty close.
Got the figures form the crop planner
http://exnil.github.io/crop_planner/
but don't know how accurate they are.