RESUMEN
Purslane is a valuable medicinal plant and study of quantity yield and phytochemical changes of them in drought is necessary. Determining the effects of nitrogen chemical and biofertilizers on quantity yield and oil content of purslane herb under drought stress and feasibility of replacing chemical fertilizers with biological fertilizers. This experiment was done in the Research farm of Shahed University in 2012 on the base of split-plot experiment in a randomized complete block design [RCBD] with three replications. The irrigation as main factor in levels of 50 +/- 3 mm, 100 +/- 3 mm and 150 +/- 3 mm of evaporation pan and also application of nitrogen fertilizers as subsidiary factor in levels including control [without fertilizer use], about 250 kg/ha fertilizer of urea, incorporation of about 2.5 L/ha of biological fertilizer with 120 kg/ha of chemical fertilizers nitrogen about 2.5 L/ha and biological fertilizer of nitrogen about 5 L/ha were considered. The treatments of drought and fertilizers had significant effects on plant height, fresh weight of leaf, stem, total fresh weight, dry weight of leaf, stem, total dry weight, grain yield, relative water content [RWC], oil content of grain and oil yield [p