The effects of biological fertilizer and chemical phosphorus fertilizer in different irrigation (water stress)on yield components of maize (Zea mays L.) were studied in a field experiment at Tehran university . A factorial split experiment based on randomized complete blocks design (RCBD) with three replications was followed in the study. Water stress treatmentsin three levels (irrigation after 75mm (normal irrigation(a1)), 100mm (moderate stress (a2)) and 125mm (sever stress(a)) evaporation from A class pan were the main plots, and two levels of biological fertilizers (application(b1) and non application(b2) ) together with chemical phosphorus fertilizers in four levels (0 (c1),75 (c2),150 (c3) and 225 (c4) kg/ha) as the factorial were sub plots. Results indicated that biological and chemical phosphorus fertilizers had a significant influence on growth, yield and yield components however cob diameter and ear length was not significantly affected by utilization of chemical phosphorus fertilizers and biological fertilizer s. The result showed that different irrigation and interaction between irrigation and biological fertilizers had significant effect on number of grain per ear.Results showed that applying the combined chemical phosphorus fertilizer with biological fertilizer can be practical and helpful method to increase maize yield and reduce the environmental pollution.
