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Nitrous Oxide Production and Reduction in Seasonally‐Flooded Cultivated Peatland Soils
Author(s) -
Hu Jing,
Inglett Kanika S.,
Wright Alan L.,
Reddy K. Ramesh
Publication year - 2016
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2015.10.0381
Subject(s) - soil water , peat , agronomy , environmental science , denitrification , biogeochemical cycle , nitrous oxide , nitrogen , chemistry , environmental chemistry , soil science , ecology , biology , organic chemistry
Core Ideas We quantified N 2 O production and reduction for cultivated intermittently flooded peatland soils. Labile organic C limited N 2 O production and reduction. High residual NO 3 − in soils inhibited N 2 O reduction. N 2 O emissions were inversely proportional to land management intensity and decreased in the order of uncultivated, turfgrass, vegetable, and sugarcane soils. Biogeochemical controls of N 2 O production and reduction during denitrification in cultivated and intermittently flooded peatland soils are poorly understood. Soils from sugarcane ( Saccharum spp.), vegetable, turfgrass, and uncultivated subtropical peatlands in the Everglades Agricultural Area (EAA) were studied to elucidate influence of land use on N 2 O production and reduction. Under ambient soil conditions, intensively managed, tilled soils (sugarcane and vegetable) had 1.5 to 4 times lower N 2 O production and reduction than turfgrass soils. Uncultivated soils had 130 to 270% higher N 2 O production than tilled soils but had similar N 2 O reduction compared with tilled soils. A lower ratio of N 2 O reduction to production was observed for uncultivated soils compared to other land uses. Net N 2 O production was highest for uncultivated soils and decreased in the order of turfgrass, vegetable, and sugarcane soils. For all land uses, N 2 O production was limited by electron donors (labile organic C) but not by electron acceptors (NO 3 − ). Depletion of labile organic C through long‐term soil oxidation after drainage resulted in limited availability of this energy source for denitrifying microorganisms. In addition, high residual NO 3 − resulting from organic N mineralization and inorganic fertilizer additions inhibited N 2 O reduction. Our results suggest that sugarcane production is likely to reduce N 2 O emissions from the EAA compared with other current land uses. Management practices with addition of labile organic C to the EAA soils may possibly result in N 2 O emission pulses because of the greater stimulation of labile organic C on N 2 O production than on N 2 O reduction.