Improvement of Soybean Yield by N-fixing Bacteria in Combination with Diammonium Phosphate Fertilizer

Manochehr Janagard Shiri Janagard, Morteza Kamrani, Yaser Hoseini


To investigate the effect of Biosoy and Barvar-2 bio-fertilizers in combination with nitrogen and phosphorus fertilizers on yield and yield components of soybean, a factorial experiment based on randomized complete block design with three replications was conducted on Research Farm of Moghan College of Agriculture and Natural Resources in 2014. The first factor included biological fertilizers in three levels (control, single inoculation with Biosoy and dual inoculation with Biosoy+Barvar-2) and the second factor included chemical fertilizers in four levels (150 kg/ha urea, 200 kg/ha diammonium phosphate, 150 kg/ha urea + 200 kg/ha diammonium phosphate and control). The results have shown that the highest pod dry weight, shoot dry weight, grain numbers, pod numbers, grain yield and biological yield were achieved when seeds inoculated with Biosoy and/or Biosoy+Barvar-2 and received 200 kg/ha diammonium phosphate. There were no significant differences between inoculation with Biosoy and dual inoculation with Biosoy and Barvar-2 at all chemical fertilizer levels. Application of 150 kg/ha urea + 200 kg/ha diammonium phosphate decreased Crop performance in both single and dual inoculation. Both types of inoculation produced higher nodule dry mass than non-inoculated seeds at all fertilizer levels. Therefore, inoculation of soybean seeds by Biosoy and/or Biosoy+Barvar2 along with application of 200 kg/ha diammonium phosphate produced the highest grain yield and saved the use of urea fertilizer.


Barvar-2, Biosoy, Diammonium phosphate, Inoculation, Nodule, Soybean, Urea.

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