Activate Arbor Elf by tapping it, untapping the enchanted forest.
Activate the Forest by tapping it, adding {U}{G}.
Activate Freed from the Real by paying {U}, untapping Arbor Elf.
Repeat.

Infinite colored mana

Arbor Elf

Freed from the Real

Fertile Ground

Activate the land with Fertile Ground attached, adding at least {1}.
Fertile Ground triggers, adding {U}.
Activate Clever Conjurer by tapping it, untapping the land.
Activate Freed from the Real's second ability by paying {U}, untapping Clever Conjurer.
Repeat.

Infinite mana lands you control can produce

Infinite mana permanents you control can produce

Clever Conjurer

Activate the land with Fertile Ground attached, adding at least {1}.
Fertile Ground triggers, adding {U}.
Activate Clever Conjurer by tapping it, untapping the land.
Activate Pemmin's Aura's first ability by paying {U}, untapping Clever Conjurer.
Repeat.

Pemmin's Aura

Activate the enchanted land by tapping it, adding {1}.
Fertile Ground triggers, adding an additional {1}.
Activate Earthcraft by tapping an untapped creature, untapping the enchanted land.
Activate Marath by paying {1} and removing a +1/+1 counter from it, creating a 1/1 Elemental token.
Repeat until Marath has no more +1/+1 counters.
Marath dies due to having 0 toughness and goes to the command zone.
Cast Marath by paying {R}{G}{W} plus commander tax, leaving zero mana unspent.
Marath enters the battlefield with a number of +1/+1 counters equal to the amount of mana spent.
Repeat any number of times.

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite storm count

Infinite tapped creature tokens

Marath, Will of the Wild

Earthcraft

Activate the basic land with Fertile Ground attached by tapping it, adding at least {1}.
Fertile Ground triggers, adding {U}.
Activate Earthcraft by tapping Horseshoe Crab, untapping the basic land.
Activate Horseshoe Crab by paying {U}, untapping it.
Repeat.
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.

Combos with "Fertile Ground"