GREENHOUSE GAS EMISSION FROM IRRIGATED KHARIF RICE GROWN UNDER ELEVATED CARBON DIOXIDE
KrishiKosh
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Title |
GREENHOUSE GAS EMISSION FROM IRRIGATED KHARIF RICE GROWN UNDER ELEVATED CARBON DIOXIDE
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Creator |
Nayak, Lopamudra
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Contributor |
Pasupalak, S.N.
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Subject |
GREENHOUSE, GAS EMISSION, KHARIF RICE, CARBON DIOXIDE
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Description |
Global warming leading to climate change is a major threat to sustainable agriculture. Increased emission of greenhouse gases (GHGs) in the era of post industrial revolution is the cause of global warming. Carbon dioxide (CO2), carbon monoxide (CO), methane (CH4) and nitrous oxide (N2O) are the major greenhouse gases of which CO2 alone contributes two-third of global warming. At the same time, elevated CO2 (eCO2) has long been considered to exert fertilization effect on crop growth through higher rate of photosynthesis. Hence, study on effect of eCO2 on rice is important. Flooded rice cultivation, whether irrigated or rainfed, is an important anthropogenic source of atmospheric CH4. Hence, there is a need to mitigate methane emission from rice field. Water management in rice avoiding continuous standing water may be a mitigation measure. It sounds good as field experiments have established that alternate wetting and drying produces similar, if not more, rice yield as continuous flooding. Hence, a controlled environment micro plot experiment was conducted in Open Top Chambers (OTCs) at the Central Research Farm, OUAT, Bhubaneswar to determine the quantity of GHG namely, CO, CO2 and CH4 from medium land kharif rice as influenced by two water management practices namely, continuous flooding and alternate wetting and drying. Elevated CO2 increased plant height by 16.7 cm at reproductive stage compared to open field. However, more shoot number per hill and LAI were produced in open field both at vegetative and reproductive stages with almost the same leaf number per shoot under all environmental conditions. Dry matter was significantly higher (3.56 x 102 kg ha- 1) in the open field at early vegetative stage but later on it was almost the same in all the environmental conditions. In elevated CO2 OTC, emissions of CH4 and CO2 were more than in ambient OTC and open field conditions during both cropping and non-cropping periods with maximum (1.4 ppm and 475.95 ppm, respectively) in November. Emission of CO was more in the open field from September to December than in both elevated CO2 OTC and ambient OTC with maximum value of 9.47 ppm in the month of November. Anaerobic bacteria count and heterotrophic bacteria count were more in elevated CO2 OTC with maximum value of 2.9 x 105 cfu g-1 and 81.2 x 105 cfu g-1, respectively in October. However, ambient OTC resulted in higher mineralisable soil microbial carbon during the cropping period (September - 78.11μg g-1 and October- 63.9 μg g-1). Continuous flooding caused more CO emission during the cropping period (September sample air- 6.3 ppm) than alternate wetting and drying. However, in noncropping period emission reduced as compared to alternate wetting and drying. Methane in the sampled air was more in continuous flooding during the cropping period with maximum of 1.03 ppm than the alternate wetting and drying. Mineralizable Soil Microbial Carbon content was more under continuous flooding only in November (51.8μg g-1). Anaerobic and Heterotrophic bacteria were more under continuous flooding with maximum value of 1.3 x 105 cfu g-1 in November and 64 x 105 cfu g-1 in September. Plant height did not differ due to water management practices at all the stages. Continuous flooding resulted in more shoot number per hill, LAI and dry matter accumulation at booting stage. However, leaf number per shoot did not vary between the two water management practices. |
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Date |
2017-01-04T11:41:17Z
2017-01-04T11:41:17Z 2013 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/94349
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Language |
en
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Relation |
Th;4031
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Format |
application/pdf
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