Key Interactions-
Urza's Mine + Urza's Power Plant + Urza's Tower
Overgrown Battlement + Wall of Blossoms or Wall of Roots
Ancient Stirrings + Fatty or Land Cards
Sylvan Scrying or Crop Rotation + Urza's Mine or Urza's Power Plant or Urza's Tower or Eye of Ugin

The strategy of Green Urza-tron is simple. Generate as much mana as possible as fast as possible, and then use it to hard-cast a fatty. Mana generation is key to this strategy; enter Urza's Mine, Urza's Power Plant, andUrza's Tower. Having just one of each of these gives you a whopping seven mana to use as you please. Add in additional Forests or copies of the Urza lands, and you'll have enough mana to cast a Charizard if you so please. Of course, you can't just hope to top-deck each of the Urza-tron lands one by one. That's about as realistic as casting a Charizard (although granted, if you could do either of these, you've probably got the game in the bag). This is where Sylvan Scrying and Crop Rotation come into play. Of these, Crop Rotation has an additional use: because you can sacrifice the land used to cast it, you can toss your extra copies of Urza lands and replace them with that one combo piece you are missing. Ancient Stirrings is not only a good land-searcher, but it also serves as a fatty-finder. Speaking of fatty-finder friends, Eye of Ugin can be searched up as a land through any of these methods--and then you can use it as your go-to guy for grabbing a fatty every turn.

The second method that Green Urza-tron uses to generate absurd amounts of mana is actually not a method at all... it's a Wall. An Overgrown Battlement, to be exact. Every creature in this deck that is not a win-condition is a wall. The deck
is constructed this way so that it can defend itself while you make land-drops. Overgrown Battlement compliments this strategy by hitting two birds with one stone--you can protect yourself and rain mana, all at the same time. Overgrown Battlement works wonders in multiples, being able to give you a hard-casted fatty even without the help of the Urza lands. It's like building your own personal mana castle. Wall of Roots also adds to the mana plan, while Wall of Blossoms helps you dig for more lands or fatties.

To add to the whole not-dying-while-you-make-land-drops plan, both Fog and Moment's Peace have been included. Sometimes this deck really doesn't need to do anything on its turn except play a land, building up to that key turn where it explodes. Fog and Moment's Peace help you do this without fear of dying as a result. The former was included because of its low mana cost, while the latter was chosen for its ability to be cast multiple times. Should a problem creature or permanent pop up that Fog is unable to stop, then you can bring out Beast Within to deal with it. Believe me, your creatures will be bigger than the beast that results from it. The inclusion of these cards, along with all of the walls, should give you plenty of breathing room to play your lands and fatties.

Green Urza-tron is different from most combo decks that try to win by turn three or four, but what it lacks in speed, it makes up for in consistency and inevitability. Your opponent cannot counter lands, much less Emrakul. This is a great deck for anyone who likes making tons of mana and casting huge monsters--on a budget. It's like dropping a Charizard on the table when you play Magic, only whithout the whole judge being called when you set your opponents cards on fire thing...