Abstract
In this field study, we evaluated the utilization of Azosprillium with organic amendments and urea in winter sorghum productivity in order to achieve the best results with minimum nitrogen utilization in Vertisols under different rainfall situations of SAT, India. Results showed that the organic materials application conserved more rainwater in top 0.60 m soil profile. Across three years of study, Azospirillum seed inoculation had a positive effect on sorghum production and produced 13% more sorghum grain and straw yields compared to 0 kg N ha–1. Sorghum grain yields were 44% higher when seeds were treated with Azospirillum and applied with 50% recommended rate of nitrogen (RRN) through urea and 50% RRN through organic materials (50:50 ratio of Leucaena loppings and farm yard manure) compared to control. Water use efficiency (WUE) was 42% greater with Azospirillum seed treatment and application 50% RRN through organic materials and 100% RRN through urea over control. Interference drawn in this study clearly indicates that low cost technology of Azospirillum seed treatment has to be adopted for higher sorghum grain yields. However, it is recommended to apply N through organic and fertilizer N in the ratio of 50:50 RRN along with Azospirillum seed treatment for sustainable sorghum yields and greater water productivity in the Vertisols of SAT, India.
Key words: Azospirillum, nitrogen, rainwater conservation, Vertisols, winter.
