Harris, Ronny (Los Alamos National Laboratory, Los Alamos National Laboratory, Atmospheric, Clima., Los Alamos, NM, 87545; Phone: 505-665-9773; Fax: 505-667-7460; Email: rdharris@lanl.gov)

Measuring Total Carbon And Nitrogen In Soils Using Laser-Induced Breakdown Spectroscopy (LIBS)

R.D. Harris *, M.H. Ebinger, C.W. Meyer, R.J. Gehl

Laser-induced breakdown spectroscopy (LIBS) has been used to measure a variety of elements in soil such as carbon, nitrogen, potassium, sulfur and phosphorus. Recent technological advances have enabled soil carbon distribution measurements to be conducted at 1 mm intervals from intact soil cores. This new application preserves information on the spatial variation of soil carbon in heterogeneous soils. The high resolution data provide new ways to estimate carbon inventories while decreasing costs. The ability to measure nitrogen in soil is also important for maintaining soil quality and maximizing productivity. Quantification of soil nitrogen with LIBS is complicated by the fact that ambient air is 78 % nitrogen. This problem can be solved by performing the analysis in a partial vacuum or by using an argon purge.