开放式空气CO2浓度升高对冬小麦生长和N吸收的影响

利用FACE(free-air carbon dioxide enrichment)技术平台，设常CO₂（ambient CO₂）和高CO₂（elevated CO₂，ambient+200 μmol·mol^-1）2个水平和常N（NN，250 kg N·hm^-2）和低N（LN，150 kg N·hm^-2）2个水平，研究CO₂浓度升高对冬小麦（Triticum aestivum L.）整个生长生物量和氮（N）吸收的影响。结果表明，CO₂浓度升高使冬小麦各部分的生物量平均增加28.3%-44.5%，拔节期增幅最大，达36.8%-91.2%，而且NN处理的生物量增幅比LN处理低。CO₂浓度升高不同程度地降低了小麦的N含量，但是增加了N的吸收，在拔节期LN处理下分别增加20.8%-29.2%，CO₂浓度升高使小麦在拔节期NN处理的N相对吸收速率增加44.1%。说明在大气CO₂浓度升高条件下，小麦会通过生物量的增加固定更多的C，增加对N养分的需求，应着重考虑提高小麦拔节期间的施氮肥水平。

Effects of Free-air Carbon Dioxide Enrichment on Growth and Uptake of Nitrogen in Winter Wheat

Increased atmospheric CO₂ supply is predicted to alter plant growth and the nutrients level. It is not clear whether the biomass of winter wheat in rice-wheat rotation system is still increased and more nitrogen application is necessary. The biomass and N uptake were studied at two concentration of CO₂[Ambient and Elevated(Ambient+200μmol·mol^-1)] and at low and normal nitrogen levels (LN,150 kg N·ha^-1 and NN, 250 kg N·ha^-1) for winter wheat. Growth and N uptake responses of winter wheat at four growth stages were determined. Results showed that the biomass of different parts of wheat increased by 28.3%-44.5% averagely. The response of biomass was significant and the increase degree was the largest at jointing stage. Under LN and NN conditions, the biomass for leave, shoot, ear and root increased significantly by 36.8%,40.9%,91.2% and 53.2%, 89.4%,52.2%, 55.5% and 67.9%, respectively. Moreover, ... ...