Conclusions
The experiment was carried out to study the effect of source of
nutrient, flow rate and length of gully on the following parameters:
nutrients uptake, dry weight of shoots and roots and No
3
-N content
in plant. The treatments under study are: source of nutrient (waste
fish farm and stock nutrient solution), flow rate (1.0, 1.5 and 2.0 L
min-1
) and length of gully (2, 3 and 4 m).The obtained results can be
summarized as follows:
• The nutrients uptakes were decreased with increasing the flow
rate and the length of gully. The total nutrients uptake values
were higher in nutrient solution than those in effluent fish
water.
• The fresh weight of shoots and roots were decreased with
increasing the flow rate and the length of gully. The fresh weight
of shoots was higher in nutrient solution than in effluent fish
water by 8.09%.
• The dry weight of shoots and roots were decreased with
increasing the flow rate and the length of gully. The dry weight
of shoots and roots were higher in nutrient solution than in
effluent fish water by 11.64 and 6.68%, respectively.
• The NO3
-N content was decreased with increasing the flow
rate and the length of gully. The NO
3
-N content was higher in
plants grown in nutrient solution than those of plants grown in
effluent fish water by 110.79%.
The best flow rate for 2 m length of gully was 1.5 L min-1
, the best
flow rate for 3 m length of gully was 1.5 L min
-1
and the best flow rate
for 4 m length of gully was 2 L min
-1
.
It could be concluded that aquaponic system is one of the economical
solutions for getting benefits from the water-waste from the fish farms
as it save nutrients and produce fresh vegetables, i.e., lettuce. With
using this system successively its cost will be decreased and became
more economic. The produced plants via this system considered as an
organic product which is more safe for human consumption.