There are a ton of benefits to urban farming.
Local food, farm to table, 100 mile diet, all of this is possible with urban agriculture. Further, urban gardens are often built over abandoned spaces in cities, converting them into green space, helping increase the beauty and value of the neighborhood.
However, there are also many challenges with urban farming. There's potential contaminants from city water runoff, zoning laws that must be overcome, laws about owning chickens, bees, and other farm animals, as well as major space constraints.