Effect of Chloride and Partial Replacement of Nitrate by Reduced Forms of Nitrogen on Nitrate, Total-N and Chloride Content of Onion (Allium cepa L.)

Authors: Ali İNAL, Aydın GÜNEŞ, Mehmet AKTAŞ

Abstract: Using a non-recirculating nutrient film system, experiment was carried out to determine the effects of chloride and reduced forms of N on nitrate, total-N and chloride concentrations of onion (Allium cepa L.) plant. The reference treatment with a nutrient solution containing 19mM NO_3 and 1.25 mM NH4 was compared with the mixed amino acid, urea, and glycine treatments and with or without additional chloride (10mM) in which 20% of the NO_3 of the reference treatments was substitutied of these reduced forms of N. Fresh and dry weights of the leaves of onion were not affected by the treatments. The nitrate content was considerably lower in the mixed amino acid treatment, being 4236 mg NO_3/kg FW as compared to reference, urea of glycine treatments. Nitrate content of the leaves in these treatments were found as fallows, 5393, 5339, 5261 mg NO_3/kg FW, respectively. Chloride also reduced nitrate content of the plants from 5816 to 4299 mg NO_3/kg FW. Reduced N treatments increased total-N contents of the plants. Chloride content of the plants was increased by chloride supply and reduced forms of N in the nutrient solution.