Ammonia Volatilization from Fertilized Turfgrass Stands1

Abstract

AbstractNitrogen applied to turfgrass stands can be lost through leaching, denitrification, or ammonia (NH3) volatilization. The purpose of this investigation was to evaluate the effects of N carrier and mode of application on NH3 volatilization from a Kentucky bluegrass (Poa pratensis L.) turf growing on an acidic (pH 6.4) Flanagan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll) soil. The NH3 which volatilized after application of any of several sulfur‐coated ureas (SCU), prilled urea, spray‐applied solubilized urea, and two liquid N products was measured by passing the airstream from microecosystems, in which the treated turfs were growing, through an indicating boric acid solution to trap NH3. Ammonia‐N losses after sulfur‐coated urea fertilization ranged from 0.2% of the applied N when the fertilization rate was 98 kg N/ha to 2.3% of the applied N when the fertilization rate was 293 kg N/ha. When prilled urea was applied at a rate of 293 kg N/ha, NH3 losses averaged 10.3% of the applied N whereas 4.6 and 1.6% of the applied N was lost after turf was fertilized with 49 kg N/ha from spray‐applied solubilized urea and prilled urea, respectively. Ammonia losses from turf treated with liquid N sources ranged from 3.2 to 4.5% of the applied N. The results of this research indicate that ammonia volatilization occurs to a limited extent in turfgrass stands growing on an acidic soil.