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Search results on 05/21/13
8315. Smith, J.L.. 1990. presentation at Palouse Cons. Farm field day. .
About 25% of the annual precipitation in the Palouse can reach groundwater, according to recent university and USGS studies. Nitrogen movement is being monitored with N-15 tracer. In the Missouri Flat Creek area, there was no trace of nitrate in shallow groundwater with applications of 110 lb N/ac. At another site, nitrate was found at 25' depth, and its origin is being traced using natural background levels of N-15, which occur at 0.366 %. Tracer studies have shown spring wheat to recover about 50% of the fertilizer applied.