کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2414665 | 1552106 | 2011 | 10 صفحه PDF | دانلود رایگان |
China consumes 32% of the world's total synthetic fertilizer nitrogen (N). Overuse of fertilizer N has become widespread, resulting in severe environmental problems. Based on a set of statistical models, we quantified the optimum N rates for rice production in terms of economic and ecological benefits. Model fitting results suggested that the dependence of rice yield, N uptake and N loss on fertilizer N application rates can be well determined by a quadratic polynomial function, a logistic function and a power function, respectively. Using these functions, the economically optimum and ecologically optimum N rates in south-eastern China were estimated to be 180–285 kg ha−1 and 90–150 kg ha−1, respectively, depending on rice subspecies, varieties and cropping systems. A case study in Jiangsu Province, where single rice with conventional japonica varieties is dominated, suggested that current N rates (∼390 kg ha−1) could be cut by 26% and 61% when the economically and ecologically optimum N rates, respectively, are adopted, saving 189 × 103 and 442 × 103 metric tons per year, respectively. Cutting one-third of the N use would not reduce rice yield but is expected to mitigate negative environmental impact in this province.
► Overuse of fertilizer N has become widespread in China.
► We quantified the optimum N rates for rice production in south-eastern China.
► The estimated optimum N rates ranged from 90 to 285 kg ha−1.
► Cutting one-third of the N use would be feasible in Jiangsu Province.
Journal: Agriculture, Ecosystems & Environment - Volume 142, Issues 3–4, August 2011, Pages 195–204