Effects of elevated ozone on the contribution of nitrogen rhizodeposition by spring wheat to different soil N pools
Effects of elevated ozone on the contribution of nitrogen rhizodeposition by spring wheat to different soil N pools
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DOI：
10.1007/s11104-018-3592-y
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发表时间：
2018-02
期刊：
影响因子：
4.9
通讯作者：
Yanhong Cao;Yi Shi;Xinchao Sun;Caiyan Lu;Xueyan Liu
中科院分区：
文献类型：
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作者：
Yanhong Cao;Yi Shi;Xinchao Sun;Caiyan Lu;Xueyan Liu
背景和目的：臭氧（O3）升高降低了来自根沉积（NdfR）的氮。然而，o3对土壤氮库nfr分配的影响尚不清楚。本研究旨在探讨nfr对不同土壤氮库的贡献及其对o3升高的响应。方法采用裂根法对春小麦进行常温（~40 ppb）和高浓度o3（60±5 ppb和110±5 ppb）处理。分析了根际土壤矿物氮、微生物生物量氮和固定铵态氮。结果O3环境下，根际氮沉降贡献了12-33%的矿物氮、10-14%的FA-N和6-16%的MB-N。升高的o3显著降低矿物质- 15ndfr和增加FA-15NdfR，但对MB-15NdfR无显著影响。矿物质- ndfr的减少可能是由于根沉积输入的减少和FA-NdfR的增加。结论o3的升高改变了nfr对土壤氮库的贡献。本研究增加了我们对ndf动态和预测未来o3水平引起的土壤N循环变化的理解。
Background and aimsElevated ozone (O3) decreases nitrogen derived from rhizodeposition (NdfR). However, the changes in the partitioning of NdfR in soil N pools due to O3remain unclear. The aims of this study were to investigate the contribution of NdfR to different soil N pools and its response to elevated O3conditions.MethodsSpring wheat was labeled with15N–urea using a split-root technique under ambient (~40 ppb) and elevated O3treatments (60 ± 5 ppb and 110 ± 5 ppb) in open-top chambers. Mineral-N, microbial biomass (MB)-N and fixed ammonium (FA)-N in rhizospheric soils were analyzed.ResultsN rhizodeposition contributed 12–33% of mineral N, 10–14% of FA-N and 6–16% of MB-N under ambient O3. Elevated O3significantly decreased mineral-15NdfR and increased FA-15NdfR but had no significant influence on MB-15NdfR. The decrease in mineral-NdfR was likely due to the decrease in rhizodeposition inputs and the increase in FA-NdfR.ConclusionsOur results showed that elevated O3altered the contribution of NdfR to soil N pools. The present study increases our understanding of the dynamics of NdfR and the changes in soil N cycling induced by projected future O3levels.