Impact of Elevated Carbon Dioxide and Cyanobacterial Inoculation on Growth, Yield and Nitrogen Fixation in Legumes under Different Doses of Phosphorus
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Date
2015
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CENTRE FOR ENVIRONMENT SCIENCE AND CLIMATE RESILIENT AGRICULTURE INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI
Abstract
Increase in the concentration of atmospheric greenhouse gases, mainly carbon
dioxide (CO2) have significant impact on crop, in terms of increase in
photosynthesis rate and growth. It also has effect onthe biogeochemical cycle.
Legumes get advantage in elevated CO2 condition than non-legumes by fixing
additional nitrogen (N). The following study was undertaken during the kharif
season of year 2014 to study the impacts of elevated CO2 and cyanonacterial
inoculation on growth, yield and N fixation of legumes under different doses of
phosphorus (P) using Free Air Carbon dioxide Enrichment Facility (FACE),
developed by Centre for Environment Science and Climate Resilient Agriculture
(CESCRA) in the IARI farm, New Delhi. Two legume crops i.e. mungbean and
cowpea were grown in two CO2 levels, ambient (395 ppm) and elevated (550±20
ppm). Crops were grown in pots with five levels of P (0, 8, 12, 16 & 20 mg P kg-1
soil) and 2 levels of calothrix sp. (with & without cyanobacteria) inoculation.
Elevated CO2and cyanobacteria application increased leaf area, photosynthesis rate
and chlorophyll content of both the crops. Elevated CO2 level increased seed yield
by 33.4% in mungbean crop and pod yield by 24.6% in cowpea crop. Cyanobacterial
inoculation increased seed yield by 16.4% in mungbean and pod yield by 14.8% in
cowpea crop. N fixation increased in elevated CO2 and higher P doses in both the
crop by increasing total nitrogenase activity. P dose of 16 mg kg-1
recorded highest N
fixation in mungbean while P dose of 20 mg kg-1
showed maximum N fixation in
cowpea crop. Plant N uptake increased by 26% in mungbean and 16.3 % in
cowpeaat elevated CO2level.Soil N status and other biological properties improved
in high CO2 and cyanobacteria applied treatments. Cyanobacteria improved
available P status of soil. P uptake in mungbean and cowpea plant increased by
30.9% and 17.7% respectively at elevated CO2 level. The study revealed that
elevated CO2and cyanobacteria application will enhance productivity and N fixation
in legumes, with cowpea being more efficient than mungbean crop. Supply of P is
important for productivity and N fixation of legumes and in present climate change
scenario P application will play crucial role.
Impact of elevated carbon dioxide and cyanobacterial
inoculation on growth, yield and nitrogen fixation in
legumes under different doses of phosphorus
Abstract
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Description
t-9277
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