Atomicrops

Edit: With the 1.5.0f1 Patch, the number of scrolls you can hold is determined by your farming stat. This may make this method to get the achievement not as effective.
NOTES: It takes about 30 farming uprade stats/points/bars to be able to hold 11 scrolls.

You will know if you have gotten Max Yield if you receive a Rose Seed from the Mayor.

Character

• Character Recommended: Thyme
• Thyme will make your days 50% longer provided that you don't get hit and you will start with a pig.
• The longer days should give a better chance to explore the biomes and the pig should not only till the soil but occasionally expand your farm.

Year

• Year Recommended: 5
• For every year the prices of guns and their upgrades increase, so its best to go for it with the cheapest weapons that you can.
• I believe that as the years go up, the cashews needed for max yield decreases; however the years are harder and you need to be able to focus on farming and exploring the biomes to get as many seeds/seed scrolls, pickaxes/expanding scrolls, farming upgrades, and animal product upgrades as possible.
• If you are able to buy the weeding tractor, this can help greatly with seed collection.

According to the AtomicropsWiki:

• Spring needs approximately 638 Cashews
• Summer needs approximately 3000 Cashews
• Fall needs approximately 4400 Cashews
• Winter needs approximately 11300 Cashews

Edit: I got this around the Doom and Bloom update for consoles.