Nitrous oxide production and emission from agricultural soil under two contrasting management systems.

摘要

An experiment was conducted at the Elora Research Station, Ontario, Canada (43°39' N 80°25' W) from December 2001 to December 2002 to investigate the effect of two management systems on emissions of N 2O; on the quantity of N2O in the soil; and on the physical, chemical and biological condition of the soil.; The experiment consisted of two treatments---a conventional (CMS) and a 'best' management system (BMS) both under winter wheat. Total emissions in the BMS (915 g N2O-N ha-1) were greater than those in the CMS (801 g N2O-N ha-1) with mean daily emissions significantly different on 28 of the 282 days (∼10%). Evidence of elevated soil N2O concentrations were observed in both treatments, however, the effect was more dramatic in the BMS. This seems to suggest an increase in microbial activity in the BMS relative to the CMS. A simple model was used to estimate the N2O flux based on the soil N2O concentration at 5 cm depth and a diffusion coefficient for N2O in the top 5 cm of soil. The model gave an order of magnitude estimate of the surface N2O flux.