Consequences of using treated wastewater and chemical fertilizers on Broccoli (Brassica oleracea) growth

Today as freshwater resources become scarcer, wastewater use is a major incentive option for conserving and expanding available water supplies. The aim of this research was to investigate the impact of normal irrigation water (Well water), chemical fertilizer, and treated urban wastewater effluent on yield quantity and quality of broccoli under micro irrigation system. The accumulation of chemicals and heavy metals in broccoli was also investigated. This study was conducted with six treatments and three replications including urban water, fertilizer mixed with urban water, urban treated wastewater, fertilizer mixed with urban treated wastewater, urban water mixed with urban treated wastewater, urban water mixed with treated wastewater and fertilizer. A sample of broccoli was picked up from each treatment in order to examine standard chemical analysis on broccoli at the end of growth season. The results indicated that the impact of application of treated wastewater compare to application of normal irrigation water on shoot fresh weight, biological performance of broccoli. The values of different elements such as K, Ca, P and Cl, was significant at level of 5 percent of probability. The results showed that different water quality had no significant impact on accumulation of heavy metals (Pb, Ni and Cd) at level of 5 percent, but significant impact was found on the accumulation of Fe, Cu, B, Mn and Zn in treated wastewater treatment at level of five percent probability. Moreover, the application of treated wastewater caused to increase the accumulation of different elements such as vitamin B6, vitamin C, and protein in different plant parts significantly.