Carbon and nitrogen partitioning of wheat and field pea grown with two nitrogen levels under elevated CO2
Carbon and nitrogen partitioning of wheat and field pea grown with two nitrogen levels under elevated CO2
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DOI：
10.1007/s11104-015-2441-5
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发表时间：
2015-06-01
期刊：
影响因子：
4.9
通讯作者：
Tang, Caixian
中科院分区：
文献类型：
--
作者：
Butterly, Clayton R.;Armstrong, Roger;Tang, Caixian
背景和目标在澳大利亚的半干旱种植系统中，作物对大气二氧化碳浓度升高的反应可能是不同的。本试验旨在研究大气CO2和氮肥互作对小麦(Triticum aestivum L.)土壤-植物系统中碳(C)和氮分配的影响。方法在大气CO2(390ppm)或高CO2(ECO(2)；550ppm)条件下，利用自由空气CO2富集法(SoilFACE)，在40或100 mg N kg(-1)下种植豌豆。用重复的~(13)CO(2)脉冲标记来定量碳通过植物向土壤的转移。结果在25~50 cm土层中，ECO(2)使豌豆地上部生物量(36%)和小麦地上部生物量(55%)增加，而小麦地上部生物量(13.5%)仅增加13.5%。在ECO(2)处理下，两种植物的全氮含量都较高，而对大田豌豆来说，这表明生物固氮作用增强。但ECO(2)提高了小麦的C/N比，即使在高N水平下也是如此。在ECO(2)下种植的小麦土壤中C-13含量较高，表明土壤C通过根际沉积略有增加。结论小麦生物量的增加和C/N比的增加可能对残留物的分解有一定的影响。ECO(2)和低氮有增加籽粒产量的趋势，但差异很大，不显着。大田豌豆在ECO(2)条件下的附加氮素含量超过了小麦籽粒中氮素的去除量，但由于干旱条件，籽粒产量低于预期。
Background and Aims Crop responses to elevated atmospheric CO2 are likely to be different in semi-arid cropping systems of Australia. This experiment aimed to investigate the interactive effects of atmospheric CO2 and nitrogen (N) fertiliser on carbon (C) and N partitioning in the soil-plant system of Wheat (Triticum aestivum L.) and field pea (Pisum sativum L.).Methods Plants were grown with 40 or 100 mg N kg(-1) under ambient CO2 (390 ppm) or elevated CO2 (eCO(2); 550 ppm) using free-air CO2 enrichment (SoilFACE). Repeated 13CO(2) pulse labelling was used to quantify C transfer via plant to the soil. Destructive sampling was performed at grain filling and maturity.Results eCO(2) increased shoot biomass of field pea (36 %) and wheat (55 %) but only increased root biomass of wheat (13.5 %) in the 25-50 cm soil layer. Total N content of both species was greater under eCO(2), and for field pea it indicated enhanced biological N-2 fixation. However, eCO(2) increased the C:N ratio of wheat even at the high N level. Greater C-13 in soil of wheat grown under eCO(2) indicated a minor increase in soil C via rhizodeposition.Conclusions Increased biomass and C:N ratio of wheat could have implications for residue decomposition. eCO(2) and low N tended to increase grain yield but the increase was highly variable and not significant. Additional N content of field pea under eCO(2) exceeded the N that would be removed in wheat grain, albeit with lower than expected grain yield due to dry conditions.