nitrogen use efficiency of spinach

abstract fertilizer use efficiency (fue) is one way of improving the fertilizer management in agriculture. in this study, spinach (spinacea oleracea) was used as a case study vegetable to determine its nitrogen use efficiency in varamin, iran. an experiment was conducted using split plot design with three replications. treatments included of five levels of n as 0, 150, 200, 250 and 300 kg ha-1 and five levels of phosphate as 0, 37.5, 50, 62.5 and 75 kg p2o5ha-1. both fresh weight and nitrate content of leaf were measured. the optimum value of fue obtained by applying 250 kg nha-1.