Like one big glass enclosement over a farm. It would allow light through, stop excessive rain and bugs from destroying food. They can control the amount of water the plants get. They would save millions
You have a very narrow scope in thinking about this issue. It wouldn't save millions. The construction of a giant glass dome over a farm would cost a lot in itself. On top of that, consider the maintenance- the glass would need cleaning and would need to be scraped of debris and dead bugs and such over time, like a windshield. Plus the irrigation and sprinkler system that would need to be in place to regulate the watering of the crops would be expensive as well. The heat would be stifling. It would change the very climate within the dome. Climate is very important to the growing of crops. You can't just change the climate of an area and expect the crops to grow better. Just think of how hot it gets when you shut off the car and sit in there for 10 minutes while the heat builds. Who can work under those conditions? Or do you mean to spend money on an elaborate fans system too?
What do you think a greenhouse is, essentially? Greenhouses are basically a glass enclosure over a piece of land. Greenhouse growers control the environment just like you suggest, but it's not a panacea. Not only do insects and disease still get in, but it's very expensive to grow crops in greenhouses. Thats why you only see high-value crops grown in them. Things like veggies, ornamentals, etc. Crops like corn/wheat/soybeans? you'll never see them grown under glass on any kind of scale, it's just too expensive, relative to the value of the crop produced.
