Modelling nitrification following urea application

[phillipsi2]

I am modelling nitrogen leaching in soil under pasture following urea application. I have successfully modelled field nitrogen leaching and crop uptake using HYDRUS 1D using the standard solute transport module but would like to also use HP1 to model the same data to include geochemical reactions by alternating rain with bore water during irrigation. I am unsure of how to include in the geochemical model the transformation of urea to ammonium to nitrate. I have rate coefficients for each of the transformation steps based on field data. If anyone can provide me with either a code or a published reference using HP1 (or PHREEQC) to model nitrogen transformations it would be greatly appreciated. Thanks ian

[Jirka]

We have quite a few tutorials and examples on the use of HP1 on the HYDRUS website:
https://www.pc-progress.com/en/Default. ... torials#k6
https://www.pc-progress.com/en/Default.aspx?H1D-lib-HP1

J.