Dear Jirka,
After using Hydrus 2/3D for simulation of the field with a drainage system, I also understood the drainage can be controlled at specific head as implemented in special boundary conditions. However in this way one value can be attributed to whole simulation time. I would like to know if it is possible to somehow control the drainage system at specific head for a specific period. like before sowing at 90cm then after V4 at 50cm and for harvest at 90cm... of course one way is to run hydrus and use the last day for the initial condition of the first day and re run for that specific head, though it will need lots of manual interferences and not easy to do.
Thanks in advance