284
C.E.Boyd
INTRODUCTION
Extensive work on water quality and fertilization of fish ponds has been
conducted
in
the
Southeastern
United
States
and
primarily
at
Auburn
University. Although none of this research was directed at carp culture, many
of
the
findings can
be applied
directly to
the management
of
carp ponds.
Therefore, a
brief
review
is provided
of research
on
water
quality
and
fertilization
in
pond
culture
of sunfish
(Lepomis spp.)—largemouth
bass
(Micropterus salmoides) combinations for sport fishing and of channel catfish
(Ictalurus punctatus) for
the
food industry. Fertilization
and other water
quality management techniques are summarized also.
I —
FERTILIZATION
Inorganic
fertilizers
have
been
used
almost
exclusively
for
the
fertilization of sport fish ponds in the Southeastern United States. However,
sport fish production
can
be stimulated equally
well with manures
(Swingle,
1947). Inorganic nutrients from fertilizers and manures enhance phytoplankton
growth
which
serves
as
the
base
of the
food web
for sunfish
and bass.
Plankton blooms also reduce
light penetration
and help
control undesirable
rooted aquatic weeds.
Because of
problems in
achieving population
balance within
1 year in
small research ponds stocked
with sunfish—bass combinations
(Swingle, 1947),
studies on
fertilization of
sportfish ponds
have relied
upon cultures
of
sunfish alone.
Experience shows
that the
results are valid
when applied in
larger ponds
which are maintained
with both species
over
many years
(Boyd,
1982). Because fertilizers serve the same
function in all types of pond fish
culture, results obtained for sunfish ponds generally should be applicable to
other
types of fish culture.
A —
Review
Swingle (1947) concluded
that
inorganic
fertilization could
increase
sunfish production by 2 to 5 times over
that achieved in unfertilized pondsSwingle and Smith (1947) recommended
a
fertilization program consisting of 8
to
14
periodic
applications
of
112
kg/ha
of 8—8—2
(% N, % P205, % K20)
fertilizer.
Later, this
recommendation
was
changed
to
employ 45 kg/ha Of
20—20—5
fertilizer
per application. The fertilization
program proved highly
effective, and it
has been
used widely
in the
United States
and
abroad.
However, research by Swingle et al.
(1963), Dobbins and Boyd (1976), and Boyd
and
SOWl€S
(1978)
demonstrated
that
nitrogen
and
potassium
were
less
important than phosphorus
in fish pond fertilizers (Table 1); phosphate—only
fertilization
can
be used in most ponds. Similar results
have been obtained
for
carp
ponds
in Europe (Mortimer, 1954) and
for
tilapia
ponds
in Asia
(Hickling, 1962). Plenty
of nitrogen
is usually
supplied through
nitrogen
fixation by blue—green algae, and natural concentrations of potassium in most
waters
are
adequate for phytoplankton growth.
Boyd (1976) found that
the
nutrient
status
of
watersheds surrounding
ponds influenced the need for fertilizer. Unfertilized
ponds in well—managed
pastures
had
higher
concentrations
of
nutrients,
harder
water,
less
transparent water, and greater plankton production than unfertilized ponds on
wooded watersheds.
Average
plankton
production
in
ponds
in
unfertilized
pastures equaled
plankton production of pond fertilized with 10 to 12 annual
applications of 45 kg/ha of 20—20—5 fertilizer. Hence, many ponds in pastureS
and other nutrient—enriched watersheds require little
or
no
fertilization.
C.E.Boyd
INTRODUCTION
Extensive work on water quality and fertilization of fish ponds has been
conducted
in
the
Southeastern
United
States
and
primarily
at
Auburn
University. Although none of this research was directed at carp culture, many
of
the
findings can
be applied
directly to
the management
of
carp ponds.
Therefore, a
brief
review
is provided
of research
on
water
quality
and
fertilization
in
pond
culture
of sunfish
(Lepomis spp.)—largemouth
bass
(Micropterus salmoides) combinations for sport fishing and of channel catfish
(Ictalurus punctatus) for
the
food industry. Fertilization
and other water
quality management techniques are summarized also.
I —
FERTILIZATION
Inorganic
fertilizers
have
been
used
almost
exclusively
for
the
fertilization of sport fish ponds in the Southeastern United States. However,
sport fish production
can
be stimulated equally
well with manures
(Swingle,
1947). Inorganic nutrients from fertilizers and manures enhance phytoplankton
growth
which
serves
as
the
base
of the
food web
for sunfish
and bass.
Plankton blooms also reduce
light penetration
and help
control undesirable
rooted aquatic weeds.
Because of
problems in
achieving population
balance within
1 year in
small research ponds stocked
with sunfish—bass combinations
(Swingle, 1947),
studies on
fertilization of
sportfish ponds
have relied
upon cultures
of
sunfish alone.
Experience shows
that the
results are valid
when applied in
larger ponds
which are maintained
with both species
over
many years
(Boyd,
1982). Because fertilizers serve the same
function in all types of pond fish
culture, results obtained for sunfish ponds generally should be applicable to
other
types of fish culture.
A —
Review
Swingle (1947) concluded
that
inorganic
fertilization could
increase
sunfish production by 2 to 5 times over
that achieved in unfertilized pondsSwingle and Smith (1947) recommended
a
fertilization program consisting of 8
to
14
periodic
applications
of
112
kg/ha
of 8—8—2
(% N, % P205, % K20)
fertilizer.
Later, this
recommendation
was
changed
to
employ 45 kg/ha Of
20—20—5
fertilizer
per application. The fertilization
program proved highly
effective, and it
has been
used widely
in the
United States
and
abroad.
However, research by Swingle et al.
(1963), Dobbins and Boyd (1976), and Boyd
and
SOWl€S
(1978)
demonstrated
that
nitrogen
and
potassium
were
less
important than phosphorus
in fish pond fertilizers (Table 1); phosphate—only
fertilization
can
be used in most ponds. Similar results
have been obtained
for
carp
ponds
in Europe (Mortimer, 1954) and
for
tilapia
ponds
in Asia
(Hickling, 1962). Plenty
of nitrogen
is usually
supplied through
nitrogen
fixation by blue—green algae, and natural concentrations of potassium in most
waters
are
adequate for phytoplankton growth.
Boyd (1976) found that
the
nutrient
status
of
watersheds surrounding
ponds influenced the need for fertilizer. Unfertilized
ponds in well—managed
pastures
had
higher
concentrations
of
nutrients,
harder
water,
less
transparent water, and greater plankton production than unfertilized ponds on
wooded watersheds.
Average
plankton
production
in
ponds
in
unfertilized
pastures equaled
plankton production of pond fertilized with 10 to 12 annual
applications of 45 kg/ha of 20—20—5 fertilizer. Hence, many ponds in pastureS
and other nutrient—enriched watersheds require little
or
no
fertilization.