Effects of NDSA fertilization on the N uptake,yield and quality of celery

A pot experiment was carried out to study the effects of NDSA(nitrogen depot with saturated ammonium) fertilization on the N uptake,yield and quality of celery(Apium graveolens L.).The results showed that NDSA fertilization with addition of DCD could significantly increase the biomass of celery,while single NDSA fertilization or solo addition of DCD could not raise yield compared to conventional fertilization.Both NDSA fertilization and addition of DCD could significantly promote N uptake and increase apparent N recovery of celery.The effect was much more pronounced when NDSA fertilization cooperated with the addition of DCD,in which the apparent N recovery was 63%.NDSA fertilization could largely decrease nitrate content of celery,while DCD did not.N application could markedly increase Vc content in celery plant,which was more pronounced if NDSA fertilization cooperated with addition of DCD.The Vc stored in the leaf of celery was 10 times higher than that in the stem.Nitrogen application and NDSA fertilization had slightly effect on the soluble sugar content in celery,but DCD could significantly increase it.