Effect of non-symbiosis nitrogen fixation bacteria on agronomic properties of cotton.

Problems and hazards caused by increasing consumption of fertilizers and their effects on Soil, human and environment health has led to use of biological sources of plant necessary nutrients in order to eliminate or reduce the use of fertilizers. Therefore, an experiment was carried out on cotton in Mazandaran and Golestan provinces with three different levels of nitrogen fertilizer including without nitrogen fertilizer (zero level), equal recommended amount and 50% lower than the recommended amount of fertilizer as main plots and use of Nitroxin biofertilizer having Azotobacter and Azospirillum bacteria as sub-plots in a split plot design. Sub-treatments were as follows: 1.5 l/ha seed coating with Nitroxin, 7.5 and 10 l/ha Notroxin applacations by irrigation water, 1.5 l/ha seed coating with Nitroxin + 7.5 l/ha Notroxin in irrigation water, 1.5 l/ha seed coating with Nitroxin + 10 l/ha Notroxin in irrigation water, and without Nitroxin biofertilizer as check treatment. Based on results in the Mazandaran province, 50% and 100% levels of recommended nitrogen fertilizer significantly produced the more number of bolls per plant, boll weight, yield of first and second picking and total yield than zero nitrogen level. In these traits, the highest and lowest amouns were obtained by 1.5 l/ha seed coating with Nitroxin + 10 l/ha Notroxin in irrigation water, and without Nitroxin biofertilizer, respectively. The highest seedcotton yield was obtained by Interaction effect of nitrogen fertilizer as 100% recommend level and 1.5 l/ha seed coating with Nitroxin + 10 l/ha Notroxin in irrigation water. In Golestan province, 100% recommended nitrogen fertilizer level produced significantly more yield than the other two treatments. 1.5 l/ha seed coating with Nitroxin + 10 l/ha Notroxin in irrigation water produced the greatest seedcotton yield. In interaction effect of two factors, the highest yield was obtained by 50% recommend nitrogen fertilizer level and 1.5 l/ha seed coating with Nitroxin + 10 l/ha Notroxin in irrigation water. Key words: Cotton, biofertilizer, Nitroxin