Nitrous oxide fluxes in a tropical shallow urban pond under influencing factors.

摘要

Fluxes of nitrous oxide (N2O) were measured in situ monthly for two years from a tropical shallow urban pond, receiving influx of agricultural runoff from the surrounding water shade and domestic sewage, located in Ujjain city, Madhya Pradesh, India. Results revealed that the shallow pond is a continuous source of N2O with relatively low efflux value (0.00 to 0.51 mg m-2 day-1) and maximum emission generally occurred during the hot seasons (77% of annual emission), with annual mean of 1.0 kg N2O ha-1 year-1. Several influencing factors like pH, temperature, total nitrogen, inorganic nitrogen stock and organic carbon were studied concomitantly with N2O gas flux measurement. N2O emissions were positively and significantly correlated with sediment total nitrogen and surface water temperature. It is concluded that the shallow tropical water body is a source of N2O flux, but does not have significant efflux compared to the terrestrial habitats..