This Is AuburnElectronic Theses and Dissertations

Integration of Intensive Aquaculture and Horticulture Crop Production




Sleeper, Adam

Type of Degree





Agricultural sectors can be integrated into mutually beneficial productions systems. Integration provides improved production sustainability, increased ecosystem health, increased human health, and polyculture. Horticulture and aquaculture are two sectors of agriculture readily integrated. Water-reuse, nutrient filtration, decreased environmental loading, decreased production costs, and product diversification are several benefits of irrigating horticulture crop production with aquaculture effluent waters. The objective of studies was to evaluate horticulture crop production in an intensive system utilizing aquaculture effluent water, as compared to standard greenhouse horticulture crop production. Effluent water from an intensive tilapia production facility was utilized as an alternative input to traditional greenhouse crop production. Tilapia production was conducted in a 29.3 x 9.1 m (96 x 30 ft) double layer polyethylenecovered greenhouse, for increased environmental control for year-round production. Fish were stocked at 80 fish·m3, in two 27.4 m x 3.8 m x 1.2 m (90 ft x 12½ x 4 ft) tanks, constructed of wood with steel I-beam and metal cable reinforcements. Due intensive nature of aquaculture production, continuous aeration supplied adequate dissolved oxygen (DO) for fish population. Dissolved oxygen and temperature of fish culture water were recorded with YSI 550A meter (YSI Inc., Yellow Springs, OH). Culture water pH, EC, and salinity were measured with YSI 63 meter. Tank water total ammonia nitrogen (TAN) levels were measured with a test kit (1.0 to 8.0mg·L-1, LaMotte Company, iii Chestertown, MD), and NO3 --N was measured with ion specific electrode meter (Cardy meter, range 0 to 9,900 mg·L-1, Spectrum Technologies, Inc., Plainfield, IL). Water samples were collected weekly and analyzed using ICAP and for NH4 determination. Water exchange rate was between 4% and 12% daily per tank. Daily feeding rate was between 27 kg to 34 kg (50 lbs to 75 lbs) feed·tank-1·day-1 with a 32% crude protein fish feed (Alabama Catfish Feed Mill, Uniontown, AL). Adjacent to the fish greenhouse, bedding plants and vegetables were irrigated utilizing effluent water provided from the tank directly, or bypassed through a settling tank as experiments required. All experiments were conducted in a 29.3 x 9.1 m (96 x 30 ft) greenhouse, with a double-layer polyethylene cover. The first experiment, conducted between January to March 2009 and July to August, 2009, clear water (CW) and effluent water (EW) irrigation was examined under varying types and rates of fertilizer inputs. Clear water treatments included a soluble 200 mg N·L-1 application, and a top-dressed controlled release fertilizer applied at 1.58 kg N·yd-3. Effluent water treatments varied between settled EW and unsettled EW. Results indicate plants grown under effluent water irrigation preformed similar to those produced under traditional production methods. In the second experiment, conducted from July to September 2009, irrigation source was again examined between CW and EW applications, while varying rates of a soluble fertilizer were compared. Treatments consisted of 200 mg N·L-1, 100 mg N·L-1, and unsettled EW. Results indicate plants grown under effluent water irrigation preformed similar to those produced under traditional production methods. Two experiments examined effects of EW irrigation on vegetable production. One study investigated greenhouse production of a 90-day sweetcorn variety, while the second study     iv   examined production of hydroponic cucumbers, in both studies plant received CW and EW irrigation as treatments. Results for the sweetcorn study, conducted January to March 2009, indicate no visual or statistical differences between treatments for plant height, yield, ear weight and length. Results for the hydroponic cucumber study, conducted from September to October 2009, indicate Manar F1 Beit Alpha cucumbers receiving EW performed similarly to plants receiving a specially formulated hydroponic fertilizer for a defined time frame, after which fruit production on plant irrigated with EW was less than the yield of fruit from plants receiving CW. Results indicate intensive aquaculture effluent water to be a viable irrigation source from production of plant species grown.