Fertilid by paying ({1} magic symbol) ({G} magic symbol) and removing a +1/+1 counter from it, causing you to search your library for a basic land card and put it on the battlefield untapped due to
Tiller Engine.
When the basic land enters,
Tiller Engine,
Tireless Provisioner and
Retreat to Kazandu trigger.
Resolve the
Tiller Engine trigger, untapping the basic land.
Resolve the
Tireless Provisioner trigger, creating a Treasure token.
Activate the Treasure by tapping and sacrificing it, adding ({G} magic symbol) .
Resolve the
Retreat to Kazandu trigger, putting a +1/+1 counter on
Fertilid.
Activate the basic land by tapping it, adding ({1} magic symbol) .
Repeat.
Results
Near-infinite landfall triggers.
Put all basic land cards from your library onto the battlefield tapped.