decreasing nitrogen concentration in nutrition solution by using enriched zeolite and its effects on greenhouse tomato

to study the effects of nitrogen on tomato plant growth and the possibility of reducing nitrogen in drainage water, two nutrient solutions (complete nutrient solution (n+) and nutrient solution with a 30% decrease in n concentration (n-)) along with and three culture media (perlite, a mixture of perlite and nh4- enriched zeolite and finally a mixture of perlite and raw zeolite) were employed for growing greenhouse tomato plant (cv. breil). the experimental designe was a split plot one with a complete randomized design of 3 replicates. results indicated that lar and ler decreased with reducing nitrogen. zeolitic media improved such growth factors as stem length, leaf number, ser, cgr and increased yield, while use of enriched zeolit decreased nitrogen in wastewater. the least slw and highest sla were obtained throught an interaction effect of complete nutrient solution and enriched zeolite bed. concentration of nitrogen in young leaves decreased with reducing nitrogen in solution but this didn't happen in nh4-enriched zeolite media.