Value

Meaning

Pressure head response

Water uptake by roots will be calculated from a potential demand and  possible reductions based on empirical functions of soil water pressure head, soil temperature and osmotic potential.

Darcy based

Water uptake by roots will be made proportional to a difference in water potential between the soil and the plant divided by estimated resistances of soil rhizosphere and plant, the so called SPAC approach. The water potential of the plant can either be assigned as a fixed value or calculated as a state variable (see PlantWaterStorage). This option is only applicable when the time resolution is chosen to be within the daily course of the day.