Comparison of ammonia-N volatilization losses from untreated granular urea and granular urea treated with NutriSphere-N®

Abstract

Development of novel methods to inhibit ammonia (NH3) volatilization losses has become a strong research focus to reduce the environmental impact of agriculture and as a potential area for growth in the fertilizer industry. European Union legislation on the regulation of NH3 emission from mineral fertilizers after 2030, will only allow urea fertilizers with reduced NH3 emissions by at least 30% to remain in use. The recent increase in fertilizer prices has also created a renewed impetus to curb these losses. This paper details the results of an experiment comparing the rates of volatilization from granular urea treated with NutriSphere-N®, untreated urea and an unfertilized control as well as placing the results in context by conducting a review of similar studies featuring NutriSphere-N®. The study was conducted in a light and temperature-controlled growth chamber using the chamber built in air flow which collected any NH3 volatilized from a flask containing fresh soil with applied treatment and transported the NH3 to an acid trap where the volatilized NH3 was captured and exhaust air was removed. The experiment ran for 3 weeks and resulting samples were analysed colorimetrically and adjusted for differences in airflow. The temporal results show that urea dominated the flux profile but the pattern of fluxes from the two fertilizer N treatments were similar. When analysed cumulatively over the duration of the experiment, the fluxes from the NutriSphere-N® treated urea were significantly (p =.018) (86%) lower than untreated urea and were not significantly different from the untreated control (p =.959).