effects of different soil fertilizing treatments (chemical, organic and integrated) on yield, yield components and seed mineral nutrients content of isabgol (plantago ovata forsk)

in order to study the effect of fertilizing treatments and limited irrigation regimes on yield and yield components of isabgol, a field experiment was conducted at experimental farm of college of agronomy and animal sciences, university of tehran. the experimental design was a split plot based on a randomized complete block design with three replications. in this research four irrigation regimes including full irrigation, light limited irrigation, moderate limited irrigation and severe limited irrigation, were assigned to the main plots and five fertilizing treatments including control (without fertilizer), chemical fertilizer, combined use of chemical fertilizer and barvar phosphate biofertilizer, cattle manure and combined use of chemical fertilizer and cattle manure, were assigned to the sub plots. the results showed that irrigation regimes had significant effect (p≤ 0.05) on all measured traits. grain yields decreased with decrement in irrigation frequency from full to severe limited irrigation; so the highest grain yields were obtained in full irrigation regime. the results also showed that fertilizing treatments had significant effect (p≤ 0.05) on all measured traits. the highest grain yield (1145 kg/ha) was obtained in combined use of chemical fertilizer and cattle manure treatment under full irrigation regime