A comparison of growth and photosynthetic characteristics of two improved rice cultivars on methane emission from rainfed agroecosystem of northeast India

Abstract Wetland rice fields serve as an important anthropogenic source of atmospheric methane, a greenhouse gas implicated in global warming. An experiment was conducted at the North Bank Plain Zone of Assam, India, during summer rice growing season (April–July 2006) in order to elucidate the effects of morpho-physiological characteristics of rice (Oryza sativa L.) plants on methane emission from paddy fields. Two improved rice cultivars viz. Disang and Luit were grown in light textured loamy soil (Sand 28.50%, Clay 30.10%, Silt 41.40%, electrical conductivity (EC) 0.43 mmhos/100 g, cation exchange capacity (CEC) 10.20 meq 100 g−1) under rainfed condition. Higher seasonal integrated methane flux was recorded in cultivar Disang (Esif = 1.38 g m−2) compared to Luit (Esif = 0.96 g m−2). Both the cultivars exhibited two emission peaks; one at active vegetative growth stage and the other at panicle initiation stage of the crop. Methane emission from the cultivars was significantly regulated by crop phenology and growth. Vegetative growth in terms of leaf number and area, root volume and length and tiller number was higher in Disang. Statistical analysis of these parameters showed a positive correlation with methane emission. On the other hand, yield and all yield-attributing parameters were found to be superior in cultivar Luit. Cultivar Luit recorded higher photosynthetic rate after panicle initiation. On the other hand, Disang recorded higher rate of photosynthesis during active vegetative growth period. In Luit, maximum partitioning of photosynthates was found towards the developing panicle, whereas in cultivar Disang, photosynthates could not be allocated sufficiently towards the panicle. In Disang, maximum partitioning of photosynthates was recorded towards the vegetative parts (including root) of the rice plant. Variation in organic carbon content of soil was observed in the field planted with two cultivars. Higher soil organic carbon content was recorded in the field planted with cultivar Disang. From this, we hypothesize that in Disang, photosynthetic carbon products were utilized as substrate by methanogens in the rhizosphere leading to more production of methane. Additionally, higher vegetative growth with high methane transport capacity (MTC) may positively contribute to higher methane emission from cultivar Disang.

[1]  R. Cicerone,et al.  Photosynthate allocations in rice plants: Food production or atmospheric methane? , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[2]  M J Kropff,et al.  Optimizing grain yields reduces CH4 emissions from rice paddy fields , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[3]  J. Lynch,et al.  Substrate flow in the rhizosphere , 1990, Plant and Soil.

[4]  S. Mariko,et al.  Mechanism of Methane Transport from the Rhizosphere to the Atmosphere through Rice Plants. , 1990, Plant physiology.

[5]  R. Conrad,et al.  Microbial processes influencing methane emission from rice fields , 2001 .

[6]  C. Neinhuis,et al.  Methanol as a rapid fixative for the investigation of plant surfaces by SEM , 1996 .

[7]  農林水産省農業環境技術研究所,et al.  CH[4] and N[2]O : global emissions and controls from rice fields and other agricultural and industrial sources , 1994 .

[8]  Hans Papen,et al.  Methane emission from rice paddies and possible mitigation strategies , 1993 .

[9]  T. Adhya,et al.  Influence of flooded and non-flooded conditions on methane efflux from two soils planted to rice , 2001 .

[10]  H. Neue,et al.  Dynamics of Dissolved Organic Carbon and Methane Emissions in a Flooded Rice Soil , 2000 .

[11]  K. Yagi,et al.  Effect of water management on methane emission from a Japanese rice paddy field: Automated methane monitoring , 1996 .

[12]  K. Yagi,et al.  Importance of physical plant properties on methane transport through several rice cultivars , 2000, Plant and Soil.

[13]  D. F. Cox,et al.  Statistical Procedures for Agricultural Research. , 1984 .

[14]  S. Mitra,et al.  Triggering of Methane Production in Rice Soils by Root Exudates , 2005 .

[15]  I. Nouchi,et al.  The dependence of methane transport in rice plants on the root zone temperature , 1997, Plant and Soil.

[16]  Changsheng Li,et al.  Field Validation of DNDC Model for Methane and Nitrous Oxide Emissions from Rice-based Production Systems of India , 2006, Nutrient Cycling in Agroecosystems.

[17]  H. Xu,et al.  Effect of Land Management in Winter Crop Season on CH4 Emission During the Following Flooded and Rice-Growing Period , 2004, Nutrient Cycling in Agroecosystems.

[18]  K. Minami,et al.  Seasonal variation in methane flux from rice paddies associated with methane concentration in soil water, rice biomass and temperature, and its modelling , 1994, Plant and Soil.

[19]  H. Neue,et al.  Factors and processes controlling methane emissions from rice fields , 1997, Nutrient Cycling in Agroecosystems.

[20]  H. Neue.  Methane emission from rice fields , 1993 .

[21]  R. Delaune,et al.  Methane production from anaerobic soil amended with rice straw and nitrogen fertilizers , 1992, Fertilizer research.

[22]  M. Kimura,et al.  Contribution of photosynthesized carbon to the methane emitted from paddy fields , 1994 .

[23]  Z. Cai,et al.  Effect of rice cultivar on CH4 production potential of rice soil and CH4 emission in a pot experiment , 2006 .

[24]  M. Kimura,et al.  Carbon cycling in rice field ecosystems in the context of input, decomposition and translocation of organic materials and the fates of their end products (CO2 and CH4) , 2004 .

[25]  J. Chanton,et al.  Methane emission from rice: Stable isotopes, diurnal variations, and CO2 exchange , 1997 .

[26]  Y. Harazono,et al.  Methane in flooded soil water and the emission through rice plants to the atmosphere , 1991 .

[27]  W. Cheng,et al.  Effects of Elevated Atmospheric CO2 Concentrations on CH4 and N2O Emission from Rice Soil: An Experiment in Controlled-environment Chambers , 2006 .

[28]  R. Hatano,et al.  Estimation of global warming potential from upland cropping systems in central Hokkaido, Japan , 2006 .

[29]  H. Marschner.  Mineral Nutrition of Higher Plants , 1988 .

[30]  B. Wang,et al.  Differences Among Rice Cultivars in Root Exudation, Methane Oxidation, and Populations of Methanogenic and Methanotrophic Bacteria in Relation to Methane Emission , 2000, Nutrient Cycling in Agroecosystems.

[31]  R. Delaune,et al.  Decreasing methane emission of rice by better crop management , 2006 .

[32]  F. Keppler,et al.  Methane emissions from terrestrial plants under aerobic conditions , 2006, Nature.

[33]  R. Sass,et al.  Methane emission from Texas rice paddy soils. 2. Seasonal contribution of rice biomass production to CH4 emission , 1997 .

[34]  L. Buendia,et al.  Mechanisms of Crop Management Impact on Methane Emissions from Rice Fields in Los Baños, Philippines , 2000, Nutrient Cycling in Agroecosystems.

[35]  L. Ziska,et al.  Climate change and rice , 1995 .

[36]  R. Lal,et al.  Mechanisms of C Sequestration in Soils of Latin America , 2006 .

[37]  Rice yield reduction by chamber enclosure: a possible effect on enhancing methane production , 2006, Biology and Fertility of Soils.

[38]  J. Singh,et al.  Methane flux from irrigated rice fields in relation to crop growth and N-fertilization , 1999 .

[39]  K. Baruah,et al.  Association between contrasting methane emissions of two rice (Oryza sativa L.) cultivars from the irrigated agroecosystem of northeast India and their growth and photosynthetic characteristics , 2008, Acta Physiologiae Plantarum.

[40]  L. H. Allen,et al.  Methane emissions of rice increased by elevated carbon dioxide and temperature. , 2003, Journal of environmental quality.

[41]  T. Adhya,et al.  Methane emission from flooded rice fields under irrigated conditions , 1994, Biology and Fertility of Soils.

[42]  M. Kimura,et al.  Input and distribution of photosynthesized carbon in a flooded rice soil , 2002 .

[43]  Paul J. Crutzen,et al.  Changing concentration, lifetime and climate forcing of atmospheric methane , 1998 .

[44]  T. Adhya,et al.  Diurnal variation in methane efflux at different growth stages of tropical rice , 1997, Plant and Soil.

[45]  P. Gupta,et al.  Methane emission characteristics and its relations with plant and soil parameters under irrigated rice ecosystem of northeast India. , 2005, Chemosphere.

[46]  Peter H. Verburg,et al.  Upscaling Regional Emissions of Greenhouse Gases from Rice Cultivation: Methods and Sources of Uncertainty , 2005, Plant Ecology.

[47]  Jeffrey A. Andrews,et al.  Spatial and temporal variability in methane emissions from rice paddies: Implications for assessing regional methane budgets , 2002, Nutrient Cycling in Agroecosystems.

[48]  H. S. Ray,et al.  Methane budget from paddy fields in India , 1996 .

[49]  H. Rennenberg,et al.  Methane transport capacity of twenty-two rice cultivars from five major Asian rice-growing countries , 2002 .

[50]  K. S. Murty,et al.  The Photosynthetic Efficiency of Some Elite Rice Hybrids and Restorers , 1997, Photosynthetica.

[51]  J. Ladha,et al.  Plant-Associated N2 Fixation (C2H2-Reduction) by Five Rice Varieties, and Relationship with Plant Growth Characters as Affected by Straw Incorporation , 1986 .

[52]  A. Bouwman.  Agronomic aspects of wetland rice cultivation and associated methane emissions , 1991 .

[53]  K. Butterbach‐Bahl,et al.  Scanning electron microscopy analysis of the aerenchyma in two rice cultivars. , 2000 .