Contribution of Atmospheric Nitrogen Compounds to N Deposition in a Broadleaf Forest of Southern China

Abstract

A one-year study in a typical red soil region of southern China was conducted to determine atmospheric nitrogen (N) fluxes of typical N compounds (NH 3, NH 4-N, NO 3-N, and NO 2) and contribution of three sources (gas, rainwater, and particles) to N deposition. From July 2003 to June 2004, the total atmospheric N deposition was 70.7 kg N ha −1, with dry deposition accounting for 75% of the total deposition. Dry NH 3 deposition accounted for 73% of the dry deposition and 55% of the total deposition. Moreover, NO 2 contributed 11% of the dry deposition and 8% of the total deposition. Reduced N compounds (NH + 4 and NH 3) were the predominate contributors, accounting for 66% of the total deposition. Therefore, atmospheric N deposition should be considered when soil acidification and critical loads of atmospheric deposition on soils are estimated.