effect of biological and chemical fertilizers on yield and yield components of some maize hybrids in south west of iran (shoushtar region)

in order to investigate effect of application of nitroxin and nitrogen chemical fertilizer on yield and yield components, split plot experiment on the basis of randomized complete block design with four replications was conducted. four levels of nitrogen fertilizer (n1: 100% chemical fertilizer, n2: 75% chemical fertilizer + 100% biological fertilizer, n3: 50% chemical fertilizer + 100% biological fertilizer, n4: 25% chemical fertilizer + 100% biological fertilizer) in main plots and three maize hybrids (h1: s.c. 704, h2: mobin, h3: karun 701) in subplots were studied. results showed that the highest grain yield belonged to 50% chemical fertilizer + 100% biological fertilizer and karun hybrid, and the lowest one belonged to 75% chemical fertilizer + 100% biological fertilizer and s.c. 704. maximum biological yield belonged to 50% chemical fertilizer + 100% biological fertilizer and karun hybrid. the highest harvest index belonged to 100% chemical fertilizer and mobin hybrid and the minimum harvest index in treatment of 75% chemical fertilizer + 100% biological fertilizer and s.c. 704 hybrid was seen. 1000-grain weight in treatment of 100% chemical fertilizer and mobin hybrid have maximum rate. maximum number of grain per ear and grain per row belonged to the treatment with 100% chemical fertilizer and s.c. 704 hybrid. in maize which require high nutrition for optimal yield, biological fertilizer application alone cannot replace chemical fertilizers, but they can be used as supplements for chemical fertilizers. finally application of n fertilizer level at 50% chemical fertilizer + 100% biological fertilizer and karun hybrid were recommended.