Start Raising Black Dragons from the Cannon Fodder Camp

In the last years of the dynasty, there was a severe drought for a hundred years, and there was no harvest. As a time traveler, Xie Yu couldn't bear to see the people unable to eat, so he made a bold decision. "As long as everyone becomes a vegetative state, won't they be able to carry out photosynthesis, and then won't they need to eat anymore?"