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Salt flux through soils can significantly influence local and global processes. For example, desert soils can atypically concentrate NO(3)(-) Lit depth in soil profiles. CaCO(3) precipitation/dissolution can play significant roles as either sinks or sources of global carbon. The objectives of this work were to develop a salt-flux model for long-term (> 1000 years) simulations of desert soils and examine the consequences of climate, soils, system inputs, and land-use change on salt movement in arid soils.

The field study was conducted at the Nevada Test Site in the northern Mojave Desert. New additions to the CALGYP model allowing: for site-specific parameterization included stochastic rainfall model, salt inputs, soil water-holding capacities, and soil CO(2) profiles. New ions added to the model included Na(+), K(+), Mg(2+), Cl(-), and NO(3)(-).

About 81% of Ca(2+) input remained within the surface 1.0m of soil as CaCO(3), which argues in favor of soil CaCO(3) serving as a recalcitrant sink for global carbon. In contrast, approximate to 99.96% of Na(+), K+, Mg(2+), Cl(-), NO(3)(-), and SO(4)(2-) ions leached to soil depths > 1.0m and 94.3% leached to soil depths >2.0m. This is true despite only 1.64% of the rainfall leached beyond 1.0 m and 0.020% of the rainfall leached beyond 2.0 m. The leachability of NO(3)(-) and Cl(-) to soil depths > 2.0 m agrees with NO(3)(-) and Cl(-) accumulations at depth in Mojave Desert soils (1.3-2.7 m). Simulation of extreme events and years with a stochastic rainfall model and accurate soil water-holding capacities are critical for modeling water and salt flux through soils. (C) 2007 Elsevier Ltd. All rights reserved.