Nutrient Availability Assessment Method in Semiarid Ecosystems in the Central Rocky Mountains, Utah
Kusbach, Antonin; Van Miegroet, Helga. 2013. Soil Sci. Soc. Am. J.
Abstract
We tested the performance of Plant Root Simulator (PRS) probes as a tool to determine plant nutrient availability across the semiarid environments of the central Rocky Mountains. We used PRS probes in a lab-field comparison representing the climatic and physiographic complexity in a high-elevation watershed in the Wasatch Range, northern Utah. We determined soil nutrient supply rates for 10 selected soils in the lab at two soil temperatures (5 and 25oC) and three moisture levels (10, 30, and 50% volumetric soil moisture content), and compared them to nutrient pools and field nutrient supply rates. Using two independent techniques, simple regressions and principal component analysis (PCA) ordination, we concluded that soil moisture content was the most important driver of nutrient supply, while incubation temperature had no influence, and nutrient pool sizes were generally poor predictors of nutrient supply rates. Lab supply rates correlated well with field PRS results. Therefore, lab PRS assays can serve as a reasonable substitute for the field use and can be beneficial for large-scale comparison of nutrient supply rates among semiarid wildland ecosystems of the western United States.
