By 2040, Chinese cities will house 1 billion residents, while urban expansion, industrialization, soil degradation and reduction of agricultural land will pose greater challenges. Hence, not only is China facing the prospect of less capacity for food production and greater demand for fresh food, but also escalating costs (including environmental costs) for food transport and packaging. Rooftop farming can reclaim some of the land displaced by urban sprawl. Locally grown vegetables would save otherwise costly packaging and transport that depend on fossil fuel. In the vertical farming production, water and fertilizers are more efficient in closed hydroponics systems, without causing eutrophication of scarce drinking water supplies. Herbicides are not necessary, and pesticide use can be substantially reduced. Hydroponically grown vegetables may be healthier than their soil-grown counterparts given the high levels of soil pollution near most urban areas. In 2016, PhD student LIU Ting and colleagues reported testing rooftop farming, and the data show that rooftop-grown leafy vegetables can be produced more cost effectively and with higher quality than market equivalents.
Liu, T., Yang, M, Han, Z., Ow, D.W. 2016. Rooftop production of leafy vegetables can be profitable and less contaminated than farm grown vegetables. Agronomy for Sustainable Development 36:41 DOI 10.1007/s13593-016-0378-6..
News media report: Conservation Magazine (Healthier and fresher greens calling from the rooftop, July 22, 2016).
News media report: Quartz Magazine (Rooftop hydroponic systems in cities produce vegetables that are cheaper and healthier than rural farms, December 15, 2016).
Edited by: Sun Yiming and Raymond