A 14.6 kyr chronology of infiltration developed from deep vadose (unsaturated) zone cores in southern Nevada is presented to assess the chronology of nitrogen loss from the active rooting zone. Soil water chemistry in the deep vadose zone is first used to develop a chronology of paleohydrology and subsequently nitrogen fluxes. While elevated nitrogen concentrations (as NO3) are commonly found in desert vadose zones, NO3/Cl ratios indicate that nitrate behaved conservatively beneath the active rooting zone. Mean nitrogen fluxes from the active root zone range from 103 to 108 mg/m2/yr and appear relatively constant over time, in spite of dramatic climate and vegetation changes. The long-term loss of nitrogen from the active rooting zone implies that nitrogen cycling processes have been relatively constant since the Pleistocene/Holocene transition, that the biological community may not be primarily limited by the availability of nitrogen, and that the loss of nitrogen into the vadose zone should be considered in desert ecosystem productivity studies. ¿ 2001 American Geophysical Union