A model for predicting the fate of nitrogen fertilizer in lowland ricefields. I: Theory uri icon

abstract

  • Equations are developed for the simultaneous movement and reaction in flooded soils of urea, ammoniacal species, carbonate species, and acids and, bases, the simultaneous uptake of N by a developing rice root system, and losses of NH3 and CO2 by volatilization from the floodwater. The equations allow for the initial distribution of urea and other reactants in the soil and floodwater, for movement both by diffusion and convection, and for the rates of urea hydrolysis, floodwater algal activity, organic-C and -N mineralization, and H+ release from roots to balance excess uptake of cations over anions. The equations are combined in a computer model which can predict the fate of N fertilizer in lowland ricefields for any combination of crop and environmental conditions.

publication date

  • 1993
  • 1993