Soil Electrochemistry - Electro-Horticulture - page 53

So what happens when the acid front eventually comes in contact with the basic front?
Whenthetwofrontscollidewithinthesoilmass,waterisformedandasharpchangeinpH
is experienced. This can also be harmful to plants. For this reason, it is advised to running
the system for too long in a continuous manner. Of course, this depends on a number of
variables including the amount of voltage applied to the system as well as the distance
between the electrodes, too.
Plants that grow in different soil conditions with different pH ranges often cannot grow
under any different soil conditions. Considering that the movement of pH through each
number on the scale results in a logarithmic increase of 10x, (e.g. A pH rise of 7.0 to 8.0 is
a 10x increase; 5.0 to 7.0 is a 100x increase, and so on), many plants cannot thrive in soils
that are outside of their normal pH ranges. It is for this reason that pH is covered here. So
forthemostpart,especially whileoperatingatlowvoltagesoverlongdistances, therateof
pH movement will be so small that it will likely not pose any problems.
Summary
Through the various physical processes that take place within soils as a direct response
to the application of electric fields, we can now appreciate a basic understanding of the
possible reasons behind the increase in growth. Covered later will be other ideas. One of
which could be the release of large amounts of soil nutrients due to electrokinetic effects.
We can also see that the acidification of the soils can also be a factor. Lastly, due to the
release of oxygen from the electrolysis reaction, an increase in sub-soil oxygen levels can
also be expected 9 . In the coming chapters we'll go deeper into these and other factors that
contributetothegainsthatcanberealizedthroughtheapplicationofelectricfieldstosoils.