Earthcraft + Fertile Ground + Simic Ragworm

Earthcraft

Fertile Ground

Simic Ragworm

How it works

1. Activate the basic land with Fertile Ground attached by tapping it, adding at least 1.
2. Fertile Ground triggers, adding .
3. Activate Earthcraft by tapping Simic Ragworm, untapping the basic land.
4. Activate Simic Ragworm by paying , untapping it.
5. Repeat.
6. If the basic land is an Island, you may add mana of any color using Fertile Ground's trigger, and you may infinitely repeat steps 3-4 with any other basic land you control.