Start Date: 2016
Principal Investigator: Lizabeth Stahl
Organization: University of Minnesota
This project will utilize existing nitrogen rate trials and on-farm sites to 1) determine the correlation between standard and Haney soil test values for nitrate-nitrogen 2) compare the optimum economic nitrogen rate generated from nitrogen rate trials to results from the Haney test, and 3) compare the sensitivity of standard and Haney testing procedures to changes in nitrate-nitrogen levels over time. This project will ultimately help evaluate the Haney test as a tool in determining nitrogen fertility needs and recommended rates of nitrogen application.
Determine the correlation between soil test values for nitrate-nitrogen based on standard soil testing procedures and the Haney test.
Compare the economic optimum nitrogen rate (EONR) determined by nitrogen rate trials to results generated from the Haney test.
Compare the sensitivity of the Haney test to standard soil sampling methods to changes in soil nitrogen levels over time.
Results of this project to date demonstrate that soil test levels for N can vary dramatically between standard soil testing methods and the Haney test. This in turn, can have significant impact on recommended fertilizer rates and economic and environmental impacts due to over- or – under-application of nutrients. Impacts of using the Haney test on P and K application rates was also studied and preliminary results were published in a U of MN Extension fact sheet.