Combined Effects Of Short Term Rainfall Patterns And Soil Texture On Soil Nitrogen Cycling -- A Modeling Analysis

Anthropogenic inputs of reactive nitrogen (N) to ecosystems have led to significant environmental consequences (Aber et al., 2003; Galloway et al., 2008). Alteration of the natural N cycle has a direct impact on water (NO3-) and atmospheric pollution (N2O, NO, NH3) (Galloway et al., 2003). Groundwater NO3- concentrations exceed drinking-water standards in many areas as a result of inputs from fertilized agriculture, resulting in potential human health effects (Power and Schepers, 1989; Spalding and Exner, 1993; Squillace et al., 2002). Elevated NO3- concentrations in leachate and surface water can also lead to eutrophication of lakes and estuaries(Lowrance et al., 1997). Nitrous oxide (N2O) is an important greenhouse gas and is involved in the destruction of stratospheric ozone (IPCC, 2001). Nitric oxide (NO) emissions contribute to tropospheric ozone formation and acid deposition (McTaggart et al., 2002). NH3 emissions affect the environment in the form of wet and dry deposition of NH4NO3 and (NH4+)2SO4 salts, causing acidification of poorly buffered soils and eutrophication (vanderWeerden and Jarvis, 1997). These concerns have stimulatedstudies to identify potential future climate change effects on N leaching and emissions from ecosystems (Skiba et al., 1997)