2008 Joint Annual Meeting (5-9 Oct. 2008): Structural Variations in Soil Organic Matter with Different Soil Layers and Locations at Juniper Butte Range, Idaho.
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784-5 Structural Variations in Soil Organic Matter with Different Soil Layers and Locations at Juniper Butte Range, Idaho.



Thursday, 9 October 2008: 9:15 AM
George R. Brown Convention Center, 381A
Jingdong Mao, Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529, C. Edward Clapp, Soil, Water, and Climate, USDA-ARS & University of Minnesota, 439 Borlaug, 1991 Upper Buford Circle, St. Paul, MN 55108, Antonio Palazzo, US Army, USA CRREL, 72 Lyme Rd., Hanover, NH 03755-1290, Nicola Senesi, Via Amendola 165, ITALY,Bari Univ., Univ. di Bari, Dip. Biol Chim. Agro for., Bari, 70126, ITALY and Klaus Schmidt-Rohr, Chemistry Department, Iowa State University, Ames, IA 50011
Naturally occurring humic substances in soils hold promise as a factor favoring the restoration of native plants. We have characterized humic acids from the Juniper Butte Range (JBR) soils in Idaho, which may promote the establishment of slickspot peppergrass (Lepidium papilliferum) seedlings, using advanced solid-state NMR techniques. A series of soil humic acids from different soil layers through the soil profile, silt (0 - 2.5 cm), vesicular (2.5 - 3.5 cm), and clay (3.5 - 15 cm), as well as inside and outside of slickspots were investigated. The advanced solid-state NMR techniques used include spectral-editing such as 13C chemical-shift-anisotropy filtering and CH2 selection to identify specific functional groups, two-dimensional 1H-13C heteronuclear correlation NMR to detect the connectivities of different functional groups, and 1H-13C recoupled long-range dipolar dephasing to selectively observe fused ring carbons. All the humic acids consist of four main structural components: aliphatic chains; peptides; sugar rings; and aromatic/olefinic carbons. Quantitative 13C NMR shows that with increasing depth the aromaticity increases. Samples from inside the slickspots have a lower aromaticity than those from outside the slickspots.
See more of: General Soil Chemistry Session
See more of: S02 Soil Chemistry