To become a Ranch Master you have to do the following things. Make sure that everything is done or no gift from your grandfather.
1. Eaten at least six Power Berries (Stamina boosters).
2. Own four adult cows.
3. Own four chickens.
4. Have an Ultra-Deluxe House.
5. Save up at least 66,000 Gold.
6. Have your happiness rate at 250 or higher.
7. Hoed and have things growing on at least 1,600 squares of your ranch (grass works best).
8. Shipped at least 4,500 units (food items). Your grandfather will come on the 30th of Winter every year to give you your year-end evaluation. It lasts all day but your animals get fed so don't worry. If you worked hard enough you will receive the fishing rod, pickax, and umbrella in that order. If you didn't work hard enough he will expand your ranch.
NOTE: You can't become Ranch Master until your second year because you can't eat six Power Berries available.