Play Gruul Turf. When it enters, Tiller Engine, Gruul Turf and Springheart Nantuko trigger.
Resolve the Tiller Engine trigger, untapping Gruul Turf.
Holding priority, activate Gruul Turf by tapping it, adding .
Resolve the Gruul Turf trigger, returning it from the battlefield to your hand.
Resolve the Springheart Nantuko trigger, causing you to pay 1 to create a token copy of Dryad of the Ilysian Grove.
Because of the additional Dryad of the Ilysian Grove token, you can play an additional land this turn.
Repeat.
This brilliant loop turns the self-bouncing nature of Gruul Turf into an endless engine of creation, fueled by Dryad of the Ilysian Grove allowing you to repeatedly replay the land. As Gruul Turf enters the battlefield, Tiller Engine immediately untaps it so you can float mana before returning the land to your hand. Meanwhile, Springheart Nantuko capitalizes on every single land drop by using that floated mana to copy your creatures, turning every iteration into an expanding army.