Environmental impact assessment of organic and conventional tomato production in urban greenhouses of Beijing city, China

Urbanization has contributed to rapid development of greenhouse vegetable production in Northern China resulting in negative environmental impacts caused by the overuse of agricultural inputs. A shift towards organic consumption and production has been promoted as one of the potential solutions to this challenge. Early indications for such a shift can already be observed in many major Chinese cities. In this paper, a life cycle assessment (LCA) approach was used to examine the environmental impacts of organic and conventional production of tomatoes in greenhouses in suburban Beijing, China. Results showed clear environmental benefits associated with a 54.87% lower environmental impact index for organic tomato production compared to its conventional counterpart. For the organic system, eutrophication and soil eco-toxicity contributed the most with 56.39% and 37.87%, respectively, mainly due to manure application. For the conventional system, aquatic eco-toxicity ranked first with 59.45%, followed by eutrophication (25.70%) and soil eco-toxicity (12.12%) - mainly due to the application of chemical pesticides and fertilizers. The results of the LCA analysis suggest a positive environmental evaluation of current trends towards organic production and consumption in urban China. However, the implications of accompanying trends towards direct, cold chain delivery as well as greater land demands within the organic system should be considered. Also, more effort should be made to help organic farmers to apply organic fertilizers more efficiently in order to reduce remaining significant soil eco-toxicity impacts from manure application.