文献类型： 外文期刊

第一作者： Zhang, Qingwen

作者： Zhang, Qingwen;Yang, Zhengli;Zhang, Hui;Yi, Jun;Zhang, Hui

作者机构：

关键词： Recovery efficiency;N-15-labelled urea;Nitrogen losses;Rice field;Anthropogenic-alluvial soil;Ningxia Irrigation Region

期刊名称：AGRICULTURE ECOSYSTEMS & ENVIRONMENT （ 影响因子：5.567； 五年影响因子：6.064 ）

ISSN： 0167-8809

年卷期： 2012 年 158 卷

页码：

收录情况： SCI

摘要： Chemical N input is essential for high rice yields. However, low recovery efficiency of chemical fertilizer N with flooding irrigation in the anthropogenic-alluvial soil resulted in N lost from the rice field in Ningxia Irrigation Region in the upper reaches of the Yellow River. With the technique of stable isotope N-15-traced urea, we conducted two years experiment to estimate the recovery efficiency and loss of applied chemical fertilizer in a rice field. The three fertilizer N treatments included 300 kg ha(-1) (N300, the conventional application rate), 240 kg ha(-1) (the optimized N application amount, N240) and no N fertilizer application treatment (CK). We estimated the recovery of N-15-labelled urea in grain, straw and root of rice and residues in soil profile. The N-15 not accounted for in the plant and soil was presumably lost. The results showed that more efficient use of N fertilizer could allow current N application rates to reduce by 20%. This would still maintain crop yields while substantially reducing N losses to the environment. The high N fertilizer application increased the N uptake by rice derived from fertilizer, and the amount of N rice taken up from soil reduced correspondingly, which resulted in the higher N surplus in soil. Under the conventional irrigation and fertilizer management level, the recovery rate of N-15-labelled urea in rice-soil system was about 48-49%. The N-15-labelled fertilizer recovery in rice plant (N-dff) was 26-30%. In the paddy soil profiles of 0-90 cm, the residual of N-15-labelled fertilizer in soil (N-dfs) were 54-70 kg ha(-1), and N residual rate in soils were 18-23%. The annual N loss from the rice field in the Irrigation Region was 28,865 tons. The distribution of N-15 abundance variability in different soil profile indicated that fertilizer N leached into the deep soil layers along with irrigation water as a result of continuous yearly rice planting. Optimization of nitrogen fertilizer can significantly reduce the amount of N residuals and N loss from the paddy field. Compared with N300, optimized nitrogen fertilizer application could decrease the loss of fertilizer N by 22-34 kg ha(-1), and reduce the amount of N surplus by 26-33 kg ha(-1) while the dry matter of rice increased 8-15% and N uptake by rice increased 2-6%. Considering the high food production and the minimum environmental threat, we should fully take into account the optimization application by reducing fertilizer N inputs. However, the interaction between irrigation management and N application rate on N use efficiency in alkaline anthropogenic-alluvial soil needs to be further studied. (C) 2012 Elsevier B.V. All rights reserved.

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