Effect of Integrated Nitrogen Management on Forage Yield of Multicut Sorghum, Available Nitrogen and Microbial Count in the Soil Yadav P.C., Sadhu A.C.*, Swarnkar P.K., Patel M.R. Department of Agronomy, B.A. College of Agriculture, Anand Agricultural University, Anand, 388110, Gujarat. *Corresponding author (Email: acs101057@yahoo.co.in
Abstract In a field experiment conducted during 2004 and 2005, application of 75 kg N ha−1 through chemical fertilizer + 25 kg N ha−1 through FYM or castor cake recorded significantly higher green forage yield and crude protein content of forage sorghum than the other treatments. Application of 100% N through organic manures (50 kg N ha−1 through FYM + 50 kg N ha−1 through castor cake) was significantly inferior in forage production, but could significantly increase the available N content and microbial count in the soil as compared to 100% N through chemical fertilizer. The maximum green forage and crude protein content of forage sorghum as well as available N content in the soil were recorded under Azotobacter + Azospirillum inoculation, although the effect on green forage yield was non-significant. The Azotobacter and Azospirillum counts were increased significantly under Azotobacter and Azospirillum inoculation treatments, respectively, while no bio-fertilizer inoculation recorded significantly lower values of soil available N as well as Azotobacter and Azospirillum population. Integration of organic and inorganic fertilizers along with bio-fertilizer inoculation increased the Azotobacter and Azospirillum population in the soil rhizosphere during both the years and enhanced the soil available N status in 2004. Application of 100% N through organic manure and dual inoculation of Azotobacter and Azospirillum registered the highest Azotobacter and Azospirillum population. Top Keywords Integrated nitrogen management, multicut forage sorghum, forage yield, crude protein, microbial count. Top |