Monday, August 1, 2011

Testing My Aquaponics System with Sweet Corn

I've just cleaned out the high tunnel and planted the entire grow bed with a sweet corn variety called "Merit."  I don't expect the corn to do very well for a number of reasons: extreme high temps during the days, high humidity, and low (but exponentially growing) levels of fish poo to name a few.  That said, I'll still be able to learn some valuable info by seeing how the corn grows relative to itself; that is, whether there is uniform growth throughout the grow bed.

Hopefully we'll see uniform growth, but disparities would not be unexpected.  Oxygen levels could be a culprit of such disparities: since I only oxygenate the water while it is in the fish tank, that means that the water steadily loses oxygen as it passes through the grow bed.  If plants don't get enough oxygen to their roots, their growth will be stunted (or they'll outright die).  If oxygen levels drop below desired levels along the water's path through the grow bed, it will be visually obvious: the plants will be continually smaller along the path.

Nutrient levels also diminish along the way as water passes through the grow bed, so another possible cause of any variations in the growth pattern may be attributable to a lack of nutrients (i.e. insufficient fish waste).

If I don't see any systemic variations, then that means the nutrient and oxygen levels are remaining sufficiently high throughout the water's path through the grow bed.  If the plants get smaller along the water's path, though, then the system is suffering from insufficient oxygen, insufficient nutrients, or both.

Here's the mighty corn patch in its current form:

And here are some gratuitous pics from the fish half of the aquaponics system:

The outside garden is full of sprouting corn.  The section in the first pic is just double rows of corn; the section in the 2nd pic features watermelon and cantaloupe plants in between the double rows of corn.  I'm hoping the combo strategy will be successful since watermelon plants send their roots much deeper than corn plants (thereby allowing the watermelon and corn to pull their water and nutrients from different strata).  We'll see.