Nutrient and heavy metal content of rapeseed (Brassica napus) irrigated with treated wastewater

National Research Centre, Agricultural Division, Field Crop Research Dept., Dokki, Egypt

Abstract

Field trials were conducted in winter season in two sites located about 20km north east of Cairo; Gabal Asfar farm (fertile soil) and Berka site (virgin soil).The trials aimed to evaluate the impact of rapeseed irrigation methods with secondary treated wastewater on yield ,quality trace elements and heavy metal content. The results clearly showed that rapeseed crop was not suited to the virgin soil as the crop produced 10% of the seed yield achieved at the fertile soil. There were significant increases in seed yield, straw and biological yields due to NPK application .Oil yields were 0.312 and 2.304 t ha^-1 on virgin and fertile soils, respectively. Treated wastewater supplied rapeseed with 35,43and 156% of the recommended requirements of N, P and K, respectively in the virgin soil while the corresponding values in the fertile soil were 79,96 and191% for N,P and K, respectively. Trace elements and heavy metal additions from wastewater were very small Seed analysis indicated that the ranges of heavy metals were within the normal ranges expected and were far below levels that would be of concern due to the high pH of both sites.