标题：DETERMINATION OF AMMONIA, PHOSPHATE, SULFIDE, IRON AND ZINC CONCENTRATION IN THE PRESENCE OF PLANTING MEDIA OF COCONUT FIBER AND CHARCOAL RICE HUSK IN KALE (IPOMOEA REPTANS POIR) CULTIVATION: THE HYDROPONICS SYSTEM
摘要：Hydroponics technology is a system of agricultural cultivation without using soil but using water as a source of nutrients for plant growth. Hydroponics is used to optimize the function of water and space as a medium for cultivation of plants. Hydroponics system was analyzed using completely randomized design with 4 time variations and 5 variations of planting medium with three replications. On measurement of ammonia and phosphate concentration of sample solution dilution was done by using aquades, then measured using UV-Vis spectrophotometer. For the determination of sulfide concentration, iron and zinc samples were first detected using HNO3 65% and then heated to 200oC until obtained by colorless solution, the sulfide concentration was measured using UV-Vis spectrophotometer and iron and zinc concentration using atomic absorption spectrophotometer flame (AAS). It has been done known that the sample of fish meal pellets solution experienced the process of maximum concentration reduction on day 30 of the hydroponics system performed. On this 30th day, hydroponic variations of the composition of the medium by using kale plants (Ipomoea reptans Poir) as plants that will help the process of reducing the concentration. In the result of measurement of ammonia, iron and zinc concentration, it was found that most variations of composition of the media with the greatest concentration reduction were medium with coconut fiber (CF) 100% and charcoal rice husk (CRH) 100% compositions, while on phosphate concentration measurement of composition variation CF: CRH=75%: 25% and CF: CRH=50%: 50%. The analysis of sulfide concentration, known that the sulfide content in the solution is below the threshold of <1 mg/L, where the lowest concentration is in media variation CRH: CF=75%: 25%, between (0.506-0.567) mg/L.
