I am wondering if anybody is using tobacco as a green mulch crop? I understand it is a really heavy feeder and depletes soil when grown as a production crop, but I figure it must be quite good if you were to use them as mulch instead. After all they're mining the soil, surely it would make that available to plants.
Really bad idea if you want to grow anything besides tobacco there. The roots exude toxic substances the same way that walnut does that reduces competition by killing off other plants. I think you are far better off utilizing any legume for green manure.