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Ammonia Volatilization from Urea Treated with NBPT and Two Nitrification Inhibitors
Author(s) -
Frame William
Publication year - 2017
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2016.08.0464
Subject(s) - chemistry , nitrification , ammonia volatilization from urea , urease , urea , ammonia , volatilisation , environmental chemistry , ammonium , soil water , inorganic chemistry , nitrogen , biochemistry , organic chemistry , soil science , environmental science
Core Ideas A comparison of ammonia volatilization from granular urea treated with two commercially available nitrification inhibitors and the interaction with the urease inhibitor, NBPT. Nitrification inhibitors increased ammonia volatilization from surface‐applied granular urea compared to untreated urea. When treating urea with nitrification inhibitors, a urease inhibitor should be applied to reduce ammonia volatilization losses. Soil type specific recommendations may be needed when applying nitrification/urease inhibitors to urea in order to maximize N use efficiency.Nitrification inhibitors reduce the rate of transformation of ammonium to nitrate, which may increase ammonia volatilization from urea‐based N fertilizers. The objective of this study was to quantify ammonia volatilization from surface‐applied granular urea treated with combinations of NBPT and the nitrification inhibitors, DCD and nitrapyrin, under controlled laboratory conditions for three soils. Nine laboratory trials evaluated select combinations of application rates for NBPT, DCD, and nitrapyrin‐treated urea. Trials were conducted on three soils selected for differences in pH, organic matter, and cation exchange capacity (CEC). Cumulative N loss as ammonia from untreated granular urea was 40.1, 44.5, and 38.2% of applied N for the Raub, Wheeling, and Pella soils, respectively. When the urease inhibitor, NBPT was applied alone at 900 mg NBPT kg −1 urea, N loss through volatilization was reduced 48.5, 43.3, and 77.9% for the Raub, Wheeling and Pella soil types, respectively. Of the soil tested, cation exchange, texture, and organic matter had the greatest impact on the rate and cumulative ammonia loss from surface‐applied untreated urea and urea treated with the urease/nitrification inhibitors. Nitrification inhibitors prevented the conversion of ammonium to nitrate by DCD and nitrapyrin, increasing ammonia losses of N in five out of six trials compared to untreated urea. When using nitrification inhibitors with surface‐applied urea, ammonia losses were decreased with the application of NBPT as well.