Orchards require only a few tweaks to get them in line with the rest of the improvements.
This is what I set as the yield curve for bonus-tile improvements with Farms and Plantations.
Ancient +2.5
Classical +2.5
Medieval +3.5
Renaissance +3.5
Industrial +4.5
Modern +6
Transhuman +9
Orchards start off at +2 to +2.5.
- Apple is +2.5: +2 food, +1 health from resource
- Lemon is +2: +1 food, +1 commerce, +1 health from resource
- Olive is +2.5: +1 food, +2 commerce, +1 happiness from resource
They then get the following additional bonuses:
- +1 commerce at Currency
- +1 food and +1 commerce at Agricultural Engineering
- +1 commerce at Globalization
- +1 food at Gene Manipulation
This gives a very close curve compared to the Farm. For Apples and Olives, the yield curve looks like this. Lemons is just a half-point lower.
Ancient +2.5
Classical +3
Medieval +3
Renaissance +3
Industrial +4.5
Modern +6
Transhuman +6
The only real change needed before the Modern Era is to move +1 commerce from
Agricultural Engineering to
Agricultural Tools. I would like to differentiate Agricultural Tools and Crop Rotation a little more. These two techs feel like they are practically twins.
Now, in the Modern Era, I would like Orchards to upgrade to Treefarms and then to Hybrid Forests. A Treefarm starts off with +1 food, +3 production, +3 commerce (+2 by itself, +1 from routes; I am assuming by the Modern Era, you have routes on every tile), an additional +0.5 yield from riverside, and +0.5 health for a total yield of +6. An Orchard is at +5 before the +1 food from Gene Manipulation kicks in. Therefore, I think the following values are appropriate to apply to Treefarms and Hybrid Forests built on fruit tiles:
- Apple: +2F, -1P, +1C
- Lemon: +1F, -1P, +3C
- Olives: +1F, -1P, +3C
This keeps the yield levels from the Orchard intact and the benefit is improved production over what the Orchard was giving.
The yield curve becomes:
Ancient +2.5
Classical +3
Medieval +3.5
Renaissance +3.5
Industrial +4.5
Modern +7.75
Transhuman +9.25
So in the Modern Era, fruit Treefarms are better than grain Farms, but the bonus is spread out over several different yield types (food, production, commerce, and health). It's actually like Watermills. I was requested to increase them a little because they were the most spread-out of improvements in terms of boosted yields. At the Transhuman Era, Dome Farm almost catches up with Hybrid Forest, but it's still best to build the appropriate improvement on the bonus tile.