Standard theories for water movement, solute transport and uptake by roots
can be applied to closed, recirculating cropping systems, even when coarse
substrates are used. Some of these systems, such as bedding systems or pott
ing plants, are vulnerable to accumulation of solutes in the root zone, whi
ch may be harmful to crop development. A two-dimensional simulation model f
or the above-mentioned processes is briefly described. This model can be us
ed, amongst other possibilities, to search for good fertigation strategies
in order to minimise solute accumulation in the root zone. This modelling a
pproach can largely reduce the number of experiments. Some simulated scenar
ios showing different distributions of the electrical conductivity in a lay
er of 15-cm coarse sand are presented. This study is not meant to be an ext
ensive search for the best fertigation strategy but to demonstrate how the
simulation model can help in finding alternative strategies.