01734naa a2200241 a 450000100080000000500110000800800410001910000170006024500620007726000090013952011620014865000090131065000150131965000120133465000100134665000160135665300170137265300100138965300180139970000180141770000190143577300380145416021991995-06-27       1974    bl ---       0--  u    #d1 aMILLS, H. A.  aAmmonia volatilization from soils.h[electronic resource]  c1974  aIf NH4+-N fertilizers are used, most agronomic crops grow best if the soil reaction is near neutrality. Previous studies have shown that if the soil pH becomes alkaline, NH3 volatilization losses of N occurs. The objective of this study was to determine whether or not a rapidly growing crop could reduce the volatilization losses of N, especially from soils above pH 7 to wich large apliccations of NH4+-N ferilizers were made. This study was conducted in a greenhouse using a closed system in which all NH3 evolved from the soil was swept away by a stream of air and collected. The amount of NH3-N evolved from the soils was measured as a function of time, soil pH, amount of N application and presence or absence of corn (Zea mays indentata Bailey) seedings. Ammonia losses with or without plants in the system increased as the soil reaction and amount of NH4+-N application increased. A sharp upward inflection in NH3-N loss occurred at pH 7.2. Plants reduced NH3-N losses by at least 60% in the alkaline soils and by lesser amounts in the acidic and neutral soils. Rapid absorption of NH4+-N by plant root appeared to account for the conservation of N.  acorn  aAdubação  aAmônia  aMilho  aNitrogênio  aCALAGEM (pH)  aSolos  aVolatização1 aBARKER, A. V.1 aMAYNARD, D. N.  tAgron. J.gv.66, p.355-358, 1974.