All plants used in these experiments were started from seed and sown directing into Styrofoam seed starter trays (Speedling, Inc. Ruskin, FL) filled with vermiculite (Therm-O-Rock East Inc., Grade 3A, New Eagle, PA). In experiment 1 lettuce (L. sativa ‘Red Sails’) and nasturtium (T. majus ‘Whirlibird Mix’) were used while in experiment 2 only lettuce was grown. In both experiments seeds were sown into either a 32 cell (nasturtium) or into a 128 cell (lettuce) tray. Three trays of each cultivar were placed in an aquaponic channel immediately after sowing. Seed germination and plant growth was visually monitored to confirm that the plants were growing well prior to the measurement of nutrient removal.
When nutrient removal was measured, the flow of effluent into the plant growing channel was temporarily stopped. A submersible magnetic drive statuary pump (Model SP 330, Tetra, Blacksburg, VA) was placed at the end of each channel to ensure good mixing within the channel. Approximately 30 min prior to the beginning of each experiment the channels were spiked with TAN to maximize the range of conditions the channels might operate under. TAN was chosen due to the strong correlation between TAN concentration and the amount of fish feed applied to the raceways. Water samples were taken at the initiation of the experiment and then at hourly intervals for up to 4 h. When plant biomass was substantial samples were taken at the start of the experiment, 30 min after the start of the experiment and then at hourly intervals.
All plants used in these experiments were started from seed and sown directing into Styrofoam seed starter trays (Speedling, Inc. Ruskin, FL) filled with vermiculite (Therm-O-Rock East Inc., Grade 3A, New Eagle, PA). In experiment 1 lettuce (L. sativa ‘Red Sails’) and nasturtium (T. majus ‘Whirlibird Mix’) were used while in experiment 2 only lettuce was grown. In both experiments seeds were sown into either a 32 cell (nasturtium) or into a 128 cell (lettuce) tray. Three trays of each cultivar were placed in an aquaponic channel immediately after sowing. Seed germination and plant growth was visually monitored to confirm that the plants were growing well prior to the measurement of nutrient removal.When nutrient removal was measured, the flow of effluent into the plant growing channel was temporarily stopped. A submersible magnetic drive statuary pump (Model SP 330, Tetra, Blacksburg, VA) was placed at the end of each channel to ensure good mixing within the channel. Approximately 30 min prior to the beginning of each experiment the channels were spiked with TAN to maximize the range of conditions the channels might operate under. TAN was chosen due to the strong correlation between TAN concentration and the amount of fish feed applied to the raceways. Water samples were taken at the initiation of the experiment and then at hourly intervals for up to 4 h. When plant biomass was substantial samples were taken at the start of the experiment, 30 min after the start of the experiment and then at hourly intervals.
การแปล กรุณารอสักครู่..