Changes farms to require more careful management of the soil. Rather than "quality" that goes either up or down (or not at all) this mod tracks Nitrogen and Phosphorus levels in the soil, with different crops having different ideal concentrations as well as pulling or fixing one or both nutrients. Each crop is loosely based on its real-world counterpart, although units are entirely arbitrary.

Additionally this mod adds three new "crops" and minor alterations to exising ones:
(New game is required to use new crops)
- Fertilize Nitrogen (adds N, 1d)
- Fertilize Phosphorus (adds P, 1d)
- Alfalfa (low yield, moderate duration: 22f/3d)
- Fruit Trees mature more quickly if following after Fruit Trees
- Quinoa food/day balance adjusted (20f/2d -> 21f/3d), but will grow well in almost any soil conditions

Stable crop rotations:
- Fertilize (N), Fruit Trees, Fruit trees
- Cover Crops, Soybeans, (Giant) Corn
- Fertilize (P), Alfalfa, (Giant) Wheat

The various adjustments create a clear progression between available options and the different research techs available. In increasing order of productivity, assuming no bonus from soil or workers:
- Fertilize (P), Alfalfa, Wheat: 6f/day (6 days)
- Fertilize (P), Alfalfa, Giant Wheat: 6.6f/day (6 days)
- Quinoa: 7f/day (3 days)
- Cover Crops, Soybeans, Corn: 8.2f/day (15 days)
- Fertilize (N), Fruit Trees, Fruit Trees: 10f/day (16 days)
- Cover Crops, Soybeans, Giant Corn: 10.5f/day (15 days)

(Soil bonuses will not always be 100% for every crop in a rotation, even under ideal conditions)

Crop Rotation