Springbloom Druid + Springheart Nantuko + Tiller Engine

Prerequisites

You have a land card in hand. You are able to play a land this turn. At least half of the basic lands in your library are Forests.

Steps

1. Play a land.
2. When the land enters, Springheart Nantuko triggers, causing you to pay {1}{G} to create a token copy of Springbloom Druid.
3. When the Springbloom Druid token enters, it triggers, causing you to sacrifice a land, then search your library for a basic Forest and another basic land and put them onto the battlefield tapped.
4. When the Forest and other basic land enter, Tiller Engine and Springheart Nantuko trigger twice.
5. Resolve both Tiller Engine triggers, untapping the basic lands.
6. Holding priority, activate both lands by tapping them, adding {1}{G}.
7. Resolve the first Springheart Nantuko trigger, choosing not to pay and creating a 1/1 Insect creature token.
8. Resolve the second Springheart Nantuko trigger, causing you to pay {1}{G} to create a token copy of Springbloom Druid.
9. Repeat from step 3 until your library contains no basic lands.