The problem with land tapping is that it's a mechanic you can't push or make strong. If you do, it leads to "unfun" gameplay that everybody hates.
Case in point
So giving it to Red is not really worth much.
There's a huge range of what can be done with land tapping below Rishadan Port, though. Even putting "(1), Tap: Tap target land" on a one-mana creature is a huge decrease in power.
In addition to repeatable tapping, land freezing also works in multiples and as a rider for other spells.
As a one shot effect for freezing all lands, that's comparable to Silence, so it would be R or 1R.
Rumbling Earth - 1R
Sorcery
Tap all lands your opponents control. Those lands don't untap during their controllers' next untap steps.
It can work as a cantrip.
Land Pillage - 2R
Sorcery
Tap up to three target lands. Those lands don't untap during their controllers' next untap steps.
Draw a card.
As a rider for another effect.
Hit Someone and Wreck Their Place - 2R
Sorcery
Deal 3 damage to target creature or player.
Tap up to two target lands. (Don't untap text.)
And as a repeatable effect beyond an activated ability.
Kessig Partier - 2R
Creature - Human Warrior
Whenever Kessig Partier attacks, tap target land defending player controls. (Don't untap text.)
2/3
I have no idea how this would be properly balanced, but there's a pretty big range of ways to adjust it. MaRo's response to
this question suggests that they intend to use land freezing to bring back red control decks based on resource denial, and
this response suggests that if it proves too weak now, they'll improve it.
EDIT: More ideas.
Kessig Squatter - 3R
Creature - Human
When Kessig Squatter enters the battlefield, tap target land an opponent controls. That land doesn't untap during its controller's untap step for as long as you control Kessig Squatter.
2/2
Fire Juggler - 1R
Creature - Goblin Shaman
When Fire Juggler dies, lands target player controls don't untap during that player's next untap step.
2/1