PARENT SESSION
Oral Session # 81: Soil Ecology II: Microorganisms and Mycorrhizae.
Presiding: SJ Hall
Thursday, August 7. 1:30 PM to 5:00 PM, SITCC Meeting Room 106.

NSF-IRCEB interannual climate variability and ecosystem processes in tallgrass praire: Non-destructive measures of soil nutrients.

Johnson, Dale^*,, Arnone, Jay, Verburg, Paul, Royce, Gitane, Wallace, Linda, Luo, Yiqi, Zerbach, Nancy,

ABSTRACT- A key element of the overall hypothesis in the ICREB study is to measure soil N availability. This is a challenging proposition at best, as no truly reliable and meaningful measure of soil N availability has yet been found; in the case of the ICREB study, we have the additional challenge of very limited plot size, making routine, destructive sampling of soils infeasible. In order to address this problem, we have tested two non-destructive methods for assessing soil N availability: Plant Root Simulator Probes (PRS), which consist of anion or cation exchange membranes imbedded in plastic stakes (Western Ag Innovations, Inc., Saskatoon, Canada) and the WECSA Soil Access System (Warrington Ecological Analysis, Ft. Collins, CO) which employs a mixed-bed cation/anion exchange resin capsule fitted to the end of a permanently-installed pvc tube. Soil N availability indices by each of these methods are compared to each other, to standard destructive soil analyses (C, N, mineral N, incubations), and to aboveground biomass production. The advantages and disadvantages of each method are discussed.

Key words: Nitrogen, Warming, Soils, Prairie