Vallluri R. Rao

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In a study on CH4 emission from flooded rice fields under irrigated conditions, fields planted with rice emitted more methane than unplanted fields. The CH4 efflux in planted plots varied with the rice variety and growth stage and ranged from 4 to 26 mg h-1m-2. During the reproductive stage of the rice plants, CH4 emission was high and the oxidation power(More)
Green manures are widely used in rice production and may influence methane efflux (CH4). Influence of application of Azolla (A. caroliniana Wild.), a widely used biofertilizer for rice (Oryza sativa L.), on CH4 efflux from a flooded alluvial soil planted to rice, and select soil and plant variables were investigated in a field experiment at Cuttack, India.(More)
Methane (CH4) emission from rice fields at Cuttack (State of Orissa, eastern India) has been recorded using an automatic measurement system (closed chamber method) from 1995–1998. Experiments were laid out to test the impact of water regime, organic amendment, inorganic amendment and rice cultivars. Organic amendments in conjunction with chemical N (urea)(More)
 Application of a commercial formulation of the herbicide butachlor (N-butoxymethyl-2-chloro-2′,6′-diethyl acetanilide) at 1 kg a.i. ha–1 to an alluvial soil planted with direct-seeded flooded rice (cv. Annada), significantly inhibited both crop-mediated emission and ebullition fluxes of methane (CH4). Over a cropping period of 110 days, the crop-mediated(More)
The placement effects of organic sources (cellulose and rice straw) at different depths on nitrogenase activity (acetylene reduction assay, ARA) associated with four tropical rice soils were investigated. Results showed that placement of organic sources in the top profile (1–2 cm) produced a higher nitrogenase activity; while placement in the 2–4 cm and(More)
Tropical rice paddy is considered to be one of the major anthropogenic source of atmospheric methane (CH4). In a field study spread over the dry and wet seasons of a calendar year, the CH4 emission from upland (oilseed and pulse) crops in the dry season and a succeeding lowland rice (Oryza sativa L.) crop in the wet season was compared with rice–rice(More)
The influence of six nitrification inhibitors (NI) on CH4 production in an alluvial soil under flooded condition was studied in a laboratory incubation experiment. The inhibition of CH4 production followed the order of sodium azide > dicyandiamide (DCD) > pyridine > aminopurine > ammonium thiosulfate > thiourea. Inhibition of CH4 production in DCD-amended(More)
Diurnal variation in CH4 efflux from continuously flooded fields planted to rice (Oryza sativa L. cv. IR-36) was examined at different crop growth stages using a closed chamber method during the wet season. CH4 emission showed a distinct diurnal pattern especially at tillering, panicle initiation and maturity stages of a field-grown rice crop, with maximum(More)
In a greenhouse study, the effect of moisture regimes (continuously flooded, continuously nonflooded, alternately flooded) on methane efflux from an alluvial soil planted to rice was studied using the closed chamber method. Methane efflux was almost 10 times more pronounced under continuously flooded conditions than under continuously nonflooded conditions.(More)