Abstract
We test the hypothesis that reduction in grain N concentration under elevated CO2 concentration (e[CO2]) is associated with N types (NH4 + and NO3 −) and their ratios. Wheat (Triticum aestivum L. cv. H45) was grown in a glasshouse under two CO2 concentrations (389 μmol mol−1 and 700 μmol mol−1), supplied with equal amount of N with different ratios of NH4 + and NO3 −: (i) 100% NO3 −–N; (ii) 50% NO3 −–N and 50% NH4 +–N; and (iii) 25% NO3 −–N and 75% NH4 +–N. Plant growth, N uptake and partitioning were measured during plant development. Plant biomass and grain yield was increased at e[CO2] when N was supplied as an equal proportion of NO3 − and NH4 +. Despite the yield increment, grain N concentration was not affected by e[CO2], in 50% NO3 −–N treatment. In contrast, grain N concentration decreased in 100% NO3 −–N and 25% NO3 −–N treatments. In 50% NO3 −–N treatment, N uptake during post-anthesis stage (from 69 to 141 days after planting) was significantly stimulated under e[CO2] compared to 100% NO3 −–N and 25% NO3 −–N treatments. We concluded that supplement of N in an equal proportion of NO3 − and NH4 + which increases post-anthesis N uptake, avoid the reduction of grain N concentration under e[CO2].
Original language | English |
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Pages (from-to) | 79-85 |
Number of pages | 7 |
Journal | Journal of Cereal Science |
Volume | 74 |
Early online date | 18 Jan 2017 |
DOIs | |
Publication status | Published - 1 Mar 2017 |
Keywords
- Elevated atmospheric CO
- Grain nitrogen
- Nitrate to ammonium ratio
- Wheat
ASJC Scopus subject areas
- Food Science
- Biochemistry