EFFICACY OF AZOTOBACTER INOCULATION UNDER GRADED DOSES OF NITROGEN FERTILIZER IN RELATION TO GROWTH, YIELD AND NITROGEN UTILIZATION EFFICIENCY OF OAT (Avena sativa L.)

A field experiment was conducted at CCS Haryana Agricultural University, Hisar, India during the winter season for three consecutive years from 1995–96 to 1997–98 to study the effect of different nitrogen levels and Azotobacter inoculation on the growth, grain yield and nitrogen utilization efficiency of two varieties of oat. The experiment was laid out in a split-plot design with three replications. The results revealed that oat variety JHO-822 was superior to OS-7 for grain yield. However, the variety OS-7 produced a higher straw yield than JHO-822. Increasing levels of nitrogen up to 60 kg/ha significantly increased the grain and straw yields over the lower doses on a pooled data basis. Nitrogen application also had a beneficial effect on the yield attributing traits of oat. Nitrogen utilization efficiency was highest at 60 kg N/ha and declined thereafter. Azotobacter inoculation was found beneficial in terms of increased grain and straw yield and higher nitrogen utilization efficiency over the uninoculated treatments.