One - perhaps surprising - benefit of clandestine marijuana growing operations is that they've helped to redefine the entire hydroponics industry in the USA; developing techniques that have dramatically lowered the costs associated with that method of farming. And increasingly, they're turning to healthier products, because growing pot costs too much in stomach lining and general anxiety.
The profit margins are lower when you're growing tomatoes and lettuce, but as one grower put it, "the vibe" is better. And you don't need pesticides to grow good food, which makes these operations attractive to stores like Whole Foods.
And perhaps counter-intuitively, Hydroponics operations use as much as 90% less water than conventional farms require.