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Austra Dikšaitytė, Irena Januškaitienė, Romualdas Juknys
Impact of elevated atmospheric CO2 concentration on pea and
white melilot at three levels of nitrogen fertilization
| Conference Information: |
9th International Conference on Environmental
Engineering, MAY 22-23, 2014 Vilnius, LITHUANIA |
| Source: |
ICEE-2014 - International Conference on Environmental
Engineering |
| Book Series: |
International Conference on Environmental Engineering
(ICEE) Selected papers |
| ISSN: |
ISSN 2029-7092 online |
| ISBN: |
978-609-457-640-9 / 978-609-457-690-4 CD |
| Year: |
2014 |
| Publisher: |
Vilnius Gediminas Technical University Press Technika |
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Abstract
Future environmental conditions will include elevated concentrations of nitrogen in the soils and elevated concentrations of carbon
dioxide in the atmosphere. Increasing CO2 concentrations are expected to enhance growth of agricultural C3 crops. However, little is
known about what are the consequences of a direct CO2 fertilization’s effect for weeds and much more attention should be given to the
combined effect of elevated CO2 and N supply on plants. In order to study their interactions on both types of plant performance, growth
chamber experiments were performed with C3 crop pea (Pisum sativum L.) and weed white melilot (Melilotus alba Medik.) from the same
family grown in a controlled conditions at different CO2 levels (400 versus 700 and 1400 ppm) combined with three levels (3, 6 and
12 g/m2
of nitrogen) of fertilization. The photosynthetic rate, transpiration rate, stomatal conductance, water-use-efficienc and dry over-
ground biomass were investigated at the end of an experiment after 10-day duration of treatment. Higher stimulatory effects of elevated
700 and 1400 ppm CO2 concentrations were on photosynthetic parameters and growth of pea than of melilot. Contrarily, higher
stimulatory effects of nitrogen supplies were on investigated parameters of melilot than of pea, but statistically significant only for
transpiration rate, stomatal conductance and water-use-efficiency, at ambient and elevated CO2 levels. The consistent response to both
these factors identified in the plants was increased nitrogen use efficiency, who also revealed the dependence of the CO2 response on N
supply, as identified by a significant CO2 × N interaction. According to these results, we concluded, that under future elevated CO2 and
nitrogen condition, both type of plants will be more efficient in resource use efficiency, but the ability of pea to assimilate additional
carbon and the competitive advantage might increase more, compared to melilot.
Keywords: Elevated CO2; N fertilization; photosynthetic rate; growth; pea, white melilot.
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