Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion Abstract Nitrogen application rates (NARs) is often overestimated over the rice (Oryza sativa L.) growing season in the Taihu Lake region of China. This is largely because only individual nitrogen (N) losses are taken into account, or

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... the inventory flows of reactive N have been limited solely to the farming process when evaluating environmental and eco-5 nomic effects of N fertilizer. Since N can permeate the ecosystem in numerous forms commencing from the acquisition of raw material, through manufacturing and use, to final losses in the farming process (e.g., N 2 O, NH 3 , NO − 3 leaching, etc.), the costs incurred also accumulate and should be taken into account if economically-optimal N rates (EONRs) are to be established. This study integrates important material and 10 energy flows resulting from N use into a rice agricultural inventory that constitutes the hub of the life-cycle assessment (LCA) method. An economic evaluation is used to determine an environmental and economic NAR for the Taihu Lake region. The analysis reveals that production and exploitation processes consume the largest proportion of resources, accounting for 77.2 % and 22.3 % of total resources, respectively. Regard-15 ing environmental impact, global warming creates the highest cost with contributions stemming mostly from fertilizer production and raw material exploitation processes. Farming process incurs the biggest environmental impact of the three environmental impact categories considered, whereas transportation has a much smaller effect. When taking account of resource consumption and environmental cost, the marginal 20 benefit of 1 kg rice would decrease from 2.4 to only 1.01 yuan. Accordingly, our current EONR has been evaluated at 185 kg N ha −1 for a single rice-growing season. This could enhance profitability, as well as reduce the N losses associated with rice growing. 6282 BGD 8, Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion Abstract BGD 8, Abstract 8, Abstract BGD 8, Abstract 8, Abstract 25 6291 BGD 8, Abstract 8, Abstract 8, Abstract 8, Abstract 8, Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion Abstract