As others have mentioned, the idea as it stands is unworkable because you don't understand how Bitcoin works. Miners don't need your transaction to mine Bitcoins. The only incentive that a miner has to process a particular transaction is the fee associated with it. Blocks can be created with no transactions other than the one that creates 50 BTC. You're not offering any incentive to a miner that he doesn't already have.

Now if you offered a fee to a miner and an exclusive right to mine that transaction rather than broadcasting it to a network, that would be something at least. As others have mentioned though, not many players have sufficient power to solo mine any more, so it would take them a highly variable random amount of time to actually generate the block with your transaction. And then you're not having zero-interest, you're just having a fee in place of the interest.