Shanghai has an enormous population; that means that a lot of food needs to be readily available for everyone. The photo below was taken near Shanghai. It lets me know that the ability to grow crops near the city does exist, so transportation would be simple and inexpensive. As you can see in the photo below, the soil looks rich.
Honestly, I have never grown rice, but it looks like it may require more than one person to tend the crops. Maybe one person holds the rice plants together, and another person ties them in a bundle.
China has an amazing system of growing fresh fruits and vegetables, even in the winter. I have seen a huge area of land covered with green houses, and they produce an amazing amount of food for the country. It is very impressive to be in northern China in the winter and enjoy eating fresh watermelon, for example. By the way, in China, the exterior of the watermelon may be carved into a beautiful design by someone in the kitchen. I think the most impressive design I have seen was a swan, which was amazingly detailed. It is very common in China for people to go to the morning market to get the fruit and vegetables they want for the day. This way they know their food is very fresh and hand selected.