Date of Award

5-2014

Document Type

Thesis

Department

Environmental Science

Thesis Advisor

Russell D. Briggs

Abstract

In order to test whether or not in situ ion-exchange resin strips can be used as a successful indicator of soil nitrogen availability as compared to the wide-spread laboratory potential mineralization method, nine plots in the Great Lakes Bioenergy Research Center located in Hickory Corners, MI were tested using both methods. The nine plots included several different crops systems with different management intensities, such as: continuous corn, continuous corn and cover crop, rotational soybean with a cover crop, rotational corn with a cover crop, switchgrass, hybrid poplar, mixed-species native grasses, successional vegetation, and restored prairie. The two methods compared were the use of ion-exchange resin strips incubated in the field plots for 28 days, and lab incubation of extracted soil cores. The results found that the use of ion-exchange resin strips were an accurate measurement of actual nitrogen flow through the system, as opposed to the potential nitrogen mineralization through the laboratory procedure. The stated hypothesis was proved correct, that soils with more intensive management, such as fertilizer, cover crops, and rotational cropping, will have more nitrogen available for plants and higher nitrogen mineralization rates than unmanaged soils. The strips have been credited to being an accurate representation of real root-soil interactions in the field, which has many potential future benefits for ecological soil studies.

Share

COinS