文献类型： 外文期刊

作者： Cui, Jihan ¹ ; Yu, Chenqun ¹ ; Qiao, Na ¹ ; Xu, Xingliang ¹ ; Tian, Yuqiang ³ ; Ouyang, Hua ¹ ;

作者机构： 1.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 110000, Peoples R China

2.Hebei Acad Agr & Forestry Sci, Minor Cereal Crops Lab Hebei Prov, Natl Foxtail Millet Improvement Ctr, Inst Millet Crops, Shijiazhuang 050035, Hebei, Peoples R China

3.Beijing Normal Univ, State Key Lab Earth Surface Proc & Resource, Beijing 100875, Peoples R China

关键词： Ammonium;Nitrate;Growth stage;Plant functional group

期刊名称：FIELD CROPS RESEARCH （ 影响因子：5.224； 五年影响因子：6.19 ）

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收录情况： SCI

摘要： It remains unclear if crops can change their preference for NH4+ or NO3- during their growth stages in alpine habits. Here, we conducted a field experiment using N-15-labelled NH4+ and NO3- to examine the preference for mineral N forms by four crop species (highland barley, forage oat, alfalfa and common vetch) at three growth stages in a Tibetan cropland. Twenty-four hours after N-15 labeling, plant and soil samples (0-15 cm) were collected for determining NH4+ and NO3+ as well as plant N content and its N-15/N-14 ratios. Soil NO3- concentration was significantly higher than NH4+ throughout the growth stages for legumes. For grasses, soil NH4+ concentration was higher than NO3- at early stages but lower at later stages. The N uptake efficiency (NUE) for alfalfa, forage oat, and common vetch decreased at the early stage, but increased later; for highland barley it decreased throughout the growth stage. The legumes preferred NO3- throughout their growth while the grasses preferred NH4+ at the early stages but switched the preference for NO3- later. We conclude that the crop N uptake preference can change during its different growing stages. (C) 2016 Elsevier B.V. All rights reserved.