The closest thing that you might find to this are the vegetable gardens that are tended to in the gated communities across Beijing, or at least in those gated communities where they are allowed.  In certain gated communities, small, and I mean, parcels of land are allotted to the Neighborhood Associations for such purposes.  Each inhabitant then "claims" a mini-plot which is farmed one growing to the next.  Additionally, in semi-rural and untended areas, villagers will often claim unused parcels of land to raise vegetables, etc. etc. 

I dont know about beijing but i know such type of things in Shandong..Google it..

I order organic food from a company called You Shi She, 优食社

 Here's there Weibo: http://weibo.com/u/2730714417?topnav=1&wvr=5&topsug=1 I get a box of fresh fruit and veg with milk and yoghurt delivered to my door twice a week for just over 1000 yuan a month!

https://www.realclearscience.com/articles/2018/06/30/china_is_spearheading_the_future_of_agriculture.html

This is going to be expensive, but they have no choice.