Effect of the Bbiofertilizers and Nitrogen Rates on Agronomic Traits and Nitrogen Efficiency Indices of Corn

To evaluate the effect of biofertilizers and nitrogen levels on agronomic traits and nitrogen efficiency indices of corn

This experiment was performed during 2016 and 2017 in the Animal Science Research Farm of Alborz Province as a split plot and in the form of a randomized complete block design with three replications. Experimental factors include nitrogen fertilizer at four levels (0, 50, 100, 200 kg.ha-1) as the main plots and biofertilizer at eight levels (no inoculation, Aztobacter, Mycorrhiza, Azospirillum, Aztobacter + Mycorrhiza, Aztobacter + Azospirillum, Mycorrhiza + Azospirillum, Mycorrhiza + Azotobacter + Azospirillum) as sub-plots were considered.

The results of analysis of variance showed that the interaction effect of nitrogen fertilizers on forage yield was significant. The results showed that increasing nitrogen application to 200 kg.ha-1 increased forage yield. The use of biofertilizers, either alone or in combination in all nitrogen fertilizer applications, increased forage yield. But the combined effect of biofertilizers had the greatest effect. However, the increase in yield was higher at lower levels of nitrogen fertilizer, especially in the control treatment (no nitrogen application). The highest nitrogen agronomical efficiency was observed in the treatment of 50 kg.ha-1 and in this case, the difference between the biofertilizer treatments was more obvious, so that the combined use of biofertilizers had the highest nitrogen agronomical efficiency.

Combined application of biofertilizers with less nitrogen fertilizer (100 kg.ha-1) can improve the nitrogen use efficiency in corn production while achieving acceptable grain and forage yield.