  We investigate certain aspects of the physical mechanisms of root growth in a
granular medium and how these roots adapt to changes in water distribution
induced by the presence of structural inhomogeneities in the form of solid
intrusions. Physical intrusions such as a square rod added into the 2D granular
medium modify water distribution by maintaining robust capillary action,
pumping water from the more saturated areas at the bottom of the cell towards
the less saturated areas near the top of the cell while the rest of the medium
is slowly devoid of water via evaporation. This water redistribution induces
`preferential tropism' of roots, guiding the roots and permitting them to grow
deeper into more saturated regions in the soil. This further allows more
efficient access to available water in the deeper sections of the medium
thereby resulting to increased plant lifetime
