Dugout aeration study answers questions
For years there have been ongoing debates as to the most effective
methods and devices for proper dugout aeration.
To answer some of
these questions, PFRA staff in Peace River collected information
that compares both different aeration devices and the differences between
aerated and non-aerated dugouts. The three year study involved 18 dugouts
the Falher, Alberta area, south of Peace River.
The main purpose of
dugout aeration is to prevent the problem of black, smelly dugout
water caused by decaying plant matter resulting from
a lack of dissolved
oxygen in the dugout water. PFRA studies have shown that unless a
dugout is properly aerated, this problem can occur not only during
but also throughout the
Aeration is more than stirring
Many farmers felt that all aerating
a dugout required was an air line into the dugout or something
to stir the water, and their
Actually, this statement is only partially correct. What the
study has shown is that devices that effectively diffuse air into
play an important
part in improving dugout water quality.
Aeration through air injection
circulates oxygen through the dugout water, but only to the depth
of the injector. Water below
dugout actually became or remained closer to an anoxic state.
To rectify this problem, the injection point must be located
Thus, the amount of dissolved oxygen throughout
the entire body of water is increased by water circulation and
into the water.
Diffusion type makes a difference
Findings have also shown that the
type of air diffusion used can make an important difference. For
tend to create
better circulation in the dugout and actually maintain
higher levels of dissolved oxygen than open-end diffusion.
open-end diffusion may create an opening in ice during winter conditions,
water that was injected with
a small bubble
diffuser tended to
maintain higher dissolved oxygen levels, while maintaining
a constant ice coverage during
In addition, maintaining oxygen saturation
(using the same pump) in dugout water, required three to 10 times
to the more efficient small bubble diffuser.
although useful for other applications, tended to increase the
temperature of the surface of
the water during
only seemed capable of making substantial differences
in dissolved oxygen levels near
the surface of the water. This left the deeper levels
of the dugout with identifiably less dissolved oxygen.
Linear diffuser most consistent
As shown in Tables 2 and 3, the
linear diffuser provides the most consistent levels of dissolved
and temperature throughout the dugout depths.
In comparing temperature
and oxygen profiles for dugouts under ice cover with different
aeration methods, the
of DO for all depths.
Therefore, the small
bubble (linear) diffuser placed on the bottom of a dugout provides
the most effective
replenishing dissolved oxygen levels
in dugout water during summer and winter