Perhaps Gruul Turf would be fun here? If you managed to get two of them, you would be guaranteed to get a land drop every turn.

Harrow seems less than ideal - Ramunap Excavator would make it better, though I wonder if all that is really worth it when there are quite a few other ways of getting more than one land to hit in a single turn.

A few land tutor spells that come to mind: Search for Tomorrow, Explore, Nissa, Vastwood Seer  ^Flip, Harvest Season.

If you really got a lot of lands going, Strata Scythe might be worth considering.

kamarupa

My problem with those suggestions is that none of them are at instant speed. Harrow is good specifically for that reason, it can be used as a combat trick, and it gets me untapped lands that I can use to chain into more spells, such as Atarka's Command. Harrow by itself is still 3 landfall triggers in a turn assuming you didn't miss your land drop for turn which is ABSURD. Ramunap Excavator is not bad, but I don’t have room to devote space to it because I need my creatures to be focused on attacking, and honestly not being able to cast lands from your graveyard is not the end of the world, and the Excavator feels kinda clunky when there's no real synergy.

Landfall aggro is a great idea- I'd be running white for Steppe Lynx and Fall of the Thran, and have a couple of Adventuring Gear and Realm Razer, focussing in more on spamming 1 drops and Edge of Autumn into a Devastating Summons the rest of the time.

The big battle is going to be making that card advantage work in modern without resorting to the pricy Life from the Loam.

lagotripha

Personally, if I was going to give the deck a land self-destruction flare, I would rather just make a new deck entirely. The list is just so tight already that I can't incorporate those synergies without moving too much away from the original purpose of the deck. Also, on your point about Adventuring Gear, I have tried equipments before, most notably Sword of the Animist, and I just found it hindered the deck's speed. Edge of Autumn was actually in the deck for awhile, and I may bring it back for further testing, I'm just not sure what I would cut.

Valakut, the Molten Pinnacle, Primeval Titan

Hey mate, I have a really competitive take on the landfall mechanic. Have a look at this:

Modern Strip Mine Fun

gb, thanks for the suggestion! I'll definitely test Valakut, the Molten Pinnacle because I like the ability to deal direct damage because the deck can struggle against strategies that flood the board.

This deck sort of seems like a janker version of TitanShift lists. I would definitely try taking a look at those lists for inspiration. Nothing wrong with playing budget decks, but its always good to try to learn from strategies that are already established within the metagame. For example, here is a list that got 2nd place at a SCG regionals this past weekend.

retreat to hagra

This is sweet! I think if you want it to be more competitive though, it needs more fetches to more consistently trigger landfall effects. Wren and Six might be good as well.

Lowenstein, I definitely would try and play more fetches if I wasn't super concerned about the budget because I think Prismatic Vista definitely has a place in the land base. The other problem is that you need plenty of basics in the deck to have targets for Cultivate and Harrow, which doesn't leave much room for many non-basic lands which can be a little awkward. Hopefully Modern Horizons 2 brings the price of fetches down which would give more wiggle room in the budget.

I tried a similar deck and i think Harrow is a good option, better than Cultivate that is too slow. For late game game i put Omnath, Locus of Rage or i was thinking about Multani, Yavimaya's Avatar; now i'll try Shatterskull Smashing  ^Flip, could be a good solution for ending a game. Explore is a good card draw for the deck. However nice deck there's a lot of nice tips that i could use for mine.