Effect of Combined Application of Organic and Chemical Nitrogen Fertilizers on Physi-ological Indices and Grain Yield of Maize (Zea mays L)

The integrated management of plant nutrition is always considered as a solution in sustainable development. In this process, the need for chemical fertilizers is reduced and helps to make the environment healthier.

Current study was done to assess effect of different level of fertilizer and biofertlizer on growth curves and crop production.

This experiment was conducted via randomized complete block design (RCBD) with three replications at Shahid Salemi field in south west of Iran-Ahvaz. The studied treatments included urea application only, Nitroxin application only, Nitroxin + 25% nitrogen from urea source, Nitroxin + 50% nitrogen from urea source, Nitroxin + 75% nitrogen from urea source, Azotobacter application only, Azotobacter + 25% nitrogen from urea source, Azotobacter + 50% nitrogen from urea source, Azotobacter + 75% nitrogen from urea source.

The results indicated that the combined application of organic and chemical nitrogen fertilizers had a significant effect on growth indices. The highest values of dry matter accumulation, leaf area index, relative growth rate, crop growth rate, and net assimilation rate were obtained from the Nitroxin + 75% nitrogen from urea source, Azotobacter + 75% nitrogen from urea source, and Nitrogen supply entirely from urea source treatments. The lowest values of growth indices were observed under 100% Nitroxin and 100% Azotobacter nitrogen source treatments. The combined fertilizer treatment significantly influenced grain yield. The highest grain yield was obtained from Nitroxin + 75% nitrogen from urea source and Azotobacter + 75% nitrogen from urea source treatments with averages of 3670 and 3500 Kg.ha-1, respectively. The lowest grain yield with average of 2610 Kg.ha-1 was obtained from the treatment using only nitrogen from the Azotobacter source.

Overall, the results of the experiment showed that the simultaneous use of organic and chemical nitrogen fertilizers can have a positive effect on physiological indices and grain yield while reducing the use of chemical fertilizers. This can significantly contribute to environmental sustainability and serves as an important strategy towards sustainable agriculture.