Issue |
Agron. Sustain. Dev.
Volume 28, Number 2, April-June 2008
|
|
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Page(s) | 175 - 180 | |
DOI | https://doi.org/10.1051/agro:2007056 | |
Published online | 15 March 2008 |
DOI: 10.1051/agro:2007056
Effect of elevated CO2 and nitrogen levels on lentil growth and nodulation
Rima Rabah Nasser1, 2, M.P. Fuller1 and A.J. Jellings11 School of Biological Sciences, University of Plymouth, Devon, PL4 8AA, UK
2 Faculty of Agriculture, Damascus University, Damascus, Syria
Accepted 3 December 2007; published online 15 March 2008
Abstract - Global carbon dioxide levels are rising, and could reach levels of 815 mol mol-1 by the year 2100. Since photosynthetic rate in C3
species under the current levels of ambient CO2 is still below
physiological saturation levels, it is anticipated that photosynthesis and
consequently productivity for most crops should be stimulated by the higher
levels of atmospheric CO2. A stronger response is expected in legumes
as nitrogen is not considered as a limiting factor for growth. This study
investigates the effect of elevated CO2 and different nitrogen
fertilizer levels on the growth and nodulation of lentils. Syrian lentil was
grown under ambient CO2 concentration of 400
mol mol-1, and
under elevated CO2 concentration of 700
mol mol-1, at five
nitrogen levels equivalent to 5, 25, 50, 75 and 100 kg N ha-1. Five
harvests were conducted over the growth period and measurements of leaf area
index (LAI), biomass dry weight, nodule number, and seed yield at the final
harvest were recorded. The results showed that, compared to the ambient
control, elevated CO2 led to a significant increase in LAI after
flowering (+20-30%), biomass dry weight (+35%) and seed yield (+60%)
from 1292.74 kg ha-1 to 2639.55 kg ha-1 at the lowest and highest
N levels respectively. Moreover these values increased with increasing
levels of nitrogen. Nodule number also increased under elevated CO2 and
the highest nodule number was observed at the nitrogen level equivalent to
50 kg N ha-1 under ambient and 75 kg N ha-1 under elevated
CO2. The average increase of nodule number for all treatments under
elevated CO2 was +52%. Examination of total nitrogen and phosphorus
concentrations in the dry matter showed that the total uptake was higher
under elevated CO2 but due to the increases in biomass concentration
levels were slightly lower. For all parameters, no significant interaction
between CO2 and nitrogen treatment was recorded.
Corresponding author: mfuller@plymouth.ac.uk
© INRA, EDP Sciences 2008