This is the liquidwater found within a
soil. This liquid normally
contains ions released from
mineral particles and
organic matter.Plants and soil
organisms take up the
nutrients and
elements they need to
grow from the soil solution.
A plant absorbs ions
that are available from the soil solution that contacts the
root, that solution becomes
deficient in those nutrients unless one of two processes occurs: a)
more solution moves from other portions of soil toward the plant
root, or
b) more ions move through the soil solution toward the
root.
Process a is called "mass flow" and is caused by plant uptake of
water, and
Process b is "ion
diffusion" caused by the
concentrationgradient
created when roots take up the ions directly surrounding them.
Active plant roots continually grow into new soil volumes to
minimize distances for water or ions to move and thus help keep
plants supplied with nutrients.
