Utilization of aquaculture effluent to supplement water and nutrient use of turfgrasses and native plants.

摘要

In the arid southwest, water is one of the major limiting factors for crop production. By integrating aquaculture and irrigated crop production, the multiple use of water can minimize the cost of rearing fish as well as irrigating crops. Waste water from aquaculture facilities typically carry metabolic and solid wastes, fecal matter, algae, and uneaten feed. These effluents contain nutrients and organic matter which are valuable as fertilizers and soil amendments.; Experiments were conducted which integrated tilapia production in tanks with use of fish effluent to supplement irrigation water for native plant production. The first experiment utilized aquaculture effluent for irrigation and supplemental fertilization of six native shrubs: Mormon tea (Ephedra viridis Cov.), big sage (Artemisia tridentata Nutt.), fourwing saltbush (Atriplex canescens (Pursh) Nutt.), winterfat (Ceratoides lanata (Pursh) J. T. Howell), rubber rabbitbrush (Chrysothamnus nauseosus (Pall.) Britt.), and mountain mahogany (Cercocarpus montanus Raf.). Plants irrigated with fish effluent were not given any fertilizer. Plants irrigated with fresh water were fertilized with Osmocote{dollar}spcircler{dollar}. Fish effluent was suitable for the production of fourwing saltbush, rubber rabbitbrush, big sage, and winterfat. Fourwing saltbush irrigated with fish effluent had the best survival. Mountain mahogany irrigated with fish effluent had the poorest growth and survival. Growbags provided better growth and survival for rubber rabbitbrush, big sage, and winterfat.; A second experiment was conducted to determine the effect of fish effluent on four turfgrasses: creeping bentgrass (Agrostis palustris Huds. 'Penncross' and 'SR 1020'), bermudagrass (Cynodon dactylon (L.) Pers. 'Sahara'), tall fescue (Festuca arundinacea Schreb. 'Cimarron'), and Kentucky bluegrass (Poa pratensis L. 'SR 2000'). Treatments were fish effluent + fertilizer, fish effluent, water + fertilizer, and water. The fish effluent + fertilizer treatment resulted in the highest dry matter for each species. 'Penncross' creeping bentgrass yielded 25% more dry matter than any other species treated with fish effluent + fertilizer. Chromameter readings resulted in higher color ratings (greener color) for both bentgrass cultivars compared to other species. Chlorophyll content corresponded to color ratings of 'Penncross' which had the highest chlorophyll content of any species. This study indicates that the addition of fish effluent as a fertilizer source had a positive effect on turfgrass growth and color.