Current Science

G. Saha ¹, S. Karmakar ², B. Kar ², R. Bhattacharya ², G. Singh ¹

Affiliations
1 Department of Agricultural Meteorology and Physics, Bidhan Chandra Krishi Viswavidyalaya, Nadia 741 252, IN
2 Department of Environmental Science, University of Kalyani, Kalyani, Nadia 741 235, IN

Abstract

Emission of nitrous oxide (N₂O) from wheat field under various management practices was measured over two years. The experimental design consisted of two winter wheat (Triticum austivum L.) varieties with three nutritional treatments and two dates of sowing. The results revealed that soil moisture and soil temperature at different depths are the key parameters influencing N₂O emission. A positive increase of N₂O flux was noticed with increasing soil moisture along with decreasing soil temperature at specific wheat phenophases. Maximum N₂O was emitted at the flowering stage. Individual factors, viz. nutrient, date of sowing and variety, and an interactive combination of these factors significantly influenced N₂O emission rates. It was also found that there was no significant association between wheat grain yield and seasonal N₂O flux.

Keywords

Emission Potentiality, Nitrous Oxide, Soil Environment, Wheat Yield.

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G. Saha ¹, B. Kar ², S. Karmakar ²

Affiliations
1 Department of Agricultural Meteorology and Physics, Bidhan Chandra Krishi Viswavidyalaya, Nadia 741 252, IN
2 Department of Environmental Science, University of Kalyani, Kalyani 741 235, IN

Abstract

Crop management practices have a significant impact on greenhouse gas (GHG) emission rates, where methane (CH₄) and nitrous oxide (N₂O) emissions from rice paddy fields are in trade-off association. A field study for two consecutive years (2013 and 2014) was conducted to continuously measure CH4 and N2O emissions from rice paddies under various agricultural management schedules like water regimes (irrigated and rainfed), transplanting dates and nutritional amendments (synthetic fertilizer with N as ammonium sulphate, P and K according to recommended dose, and vermicompost). Rainfed situation incurred a drop in CH₄ fluxes triggering substantial N₂O emission. Ammonium sulphate application tended to reduce CH₄ emissions, but significantly increased N₂O emissions. Enhanced CH₄ fluxes were measured during panicle initiation to flowering stage while, maximum N₂O emissions were recorded during flowering to milking stage of rice crop. Significant interrelationship between the gases was evaluated. In addition, seasonal average of CH₄ and N₂O emissions was also correlated with rice production. In conclusion, GHG concentration may control to some extent optimizing rice productivity through implementing and improving crop- and location-specific management practices.

Keywords

Agroclimatic Region, Methane, Nitrous Oxide, Rice Field.

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