Environmental impact assessment via life cycle analysis for organic and conventional apple productions

To set the scientific basis for sustainable agricultural development and ecological civilization construction in China, this study analyzed the impacts of organic and conventional apple productions on environment in Fushan of Shanxi Province, Baishui of Shaanxi Province and Tianshui of Gansu Province through life cycle analysis method. Data were collected via field visits and farmer interviews. The study used unit apple production as the basis for comparative analysis. The system boundary of apple production defined in the study included materials production and cropping stages. The impacts of apple production on environments were assessed at four aspects-energy consumption, global warming, environmental acidification and eutrophication. It was found that nutrient use efficiency in organic apple production in Fushan of Shanxi Province was higher than that in conventional apple production, which was the reverse of the results for Baishui of Shaanxi Province and Tianshui of Gansu Province. The yield of organic apple was similar to that of conventional apple in Baishui of Shaanxi Province and Tianshui of Gansu Province, while the yield of organic apple in Fushan of Shanxi Province was only 69% that of conventional apple. Nitrogen, phosphorous and potassium inputs in organic apple production in Fushan of Shanxi Province were 6.8%-18.8% those of conventional apple production. For the other two regions, however, nutrient input in organic production was about 72.7%-228.8% that of conventional production. Energy consumption per unit organic apple product in the three regions accounted for less than 26% of the conventional product; i.e., energy utilization efficiency of organic apple was higher than that of conventional apple. Among the four environmental impacts (energy consumption, global warming, environmental acidification and eutrophication), eutrophication contributed the most (over 80%) to total environmental impact. The impact of global warming for unit organic apple product in Fushan of Shanxi Province was smaller than that of conventional product (organic product was only 23% that of conventional product). However, organic apple production in Baishui of Shaanxi Province and Tianshui of Gansu Province was much higher than that of conventional production (organic apple was respectively 356% and 138% conventional apple for the two areas). Environmental acidification and eutrophication under organic apple production in Fushan of Shanxi Province was lower than that under conventional production, but the results for Tianshui of Gansu Province and Baishui of Shaanxi Province were the reverse. Total environmental impact of apple production was the highest in Baisui of Shaanxi Province, followed by Tianshui of Gansu Province and then Fushan of Shanxi Province. Total environmental impact of organic apple production was 22% that of conventional apple production in Fushan of Shanxi Province. Then in Baishui of Shaanxi Province and Tianshui of Gansu Province, total environmental impacts of organic apple production were respectively 356% and 138% those of conventional apple production. This discrepancy was mainly due to differences in the amount and types of fertilizer used. The results showed that organic production had crop yields comparable to those of conventional agriculture in terms of nutrient input. However, it also led to higher negative environmental impacts and lower nutrient and energy use efficiency in organic production.