Effects of organic, chemical and biological sources of nitrogen on nitrogen use efficiency in black seed (Nigella sativa L.)

In order to investigate the effects of organic، chemical and biological sources of nitrogen on nitrogen and fertilizer use efficiency of black seed (Nigella sativa L.)، a field experiment was conducted at Agricultural Research Station of Ferdowsi University of Mashhad، Iran، in 2009-2010. The experiment was arranged by using a completely randomized block design based on factorial fashion with three replications and twenty-five treatments. The experimental treatments included different sources of nitrogen (manure، compost، vermicompost، urea fertilizer and control) and different biological fertilizers (nitroxin including Azotobacter sp. and Azospirillum sp)، mycorrhizae، nitroxin+mycorrhizae، biosulfur ((including Thiobacillus sp.) +sulfur and control (no biofertilizer). Results indicated that in spite of significant effects of sources of nitrogen and biological fertilizer on nitrogen and fertilizer use efficiency of black seed، interactions between these factors had no significant effects on mentioned traits. Results showed that nitrogen and fertilizer use efficiency of black seed in organic fertilizer treatments were significantly higher than that of urea fertilizer. The biological fertilizer had no significant increasing effects on mentioned traits، except biosulfur + sulfur bentonite. It seems that in the alkalic soils، biosulfur biofertilizer plus sulfur could contribute in increasing the nitrogen uptake and use efficiency of black seed، by decreasing the soil pH.