The achievement is quite tricky. I tried a few times and finally got the achievement. Here is the guide to help you out.
I tried a few times but I still cannot get the achievement. It may be some factors not letting you get it. So, I share my progress:
- Normal difficulty in sandbox mode.
- 100 Potato Farms to produce 80000 qty.
- 20 Granaries to store 1.5X production by Botanic Garden.
- Botanic Garden is activated through out the year.
- For the record: Unemployement -34 during farming; 31% unemployment during idle.
- Wait until year end to get the achievement.
- In report screen: 120000 stocked; 80000 production this year.
Suppose all 20 Granaries are fully filled:
I am not sure that Botanic Garden is essential in this model. I just got the achievement after a few times until I build 100 farms and activate the Garden in the same gameplay.