Effect of different agricultural practices on population dynamics of Azotobacter chroococcum and on its nitrogen fixing potentiality in Trans-Ganga and Trans-Yamuna plains of India

A study was conducted for two consecutive years 2003-04 and 2004-05 at Allahabad, one of the most fertile regions of Indo-Gangetic plane on wheat crop. The aim was to assess the effect of different agricultural practices on the population dynamics and nitrogen fixing potentiality of free living aerobic nitrogen fixing bacteria Azotobacter chroococcum. Heavy input of fertilizers, mechanical tillage, frequent irrigation, monocropping have resulted in decrease in population of Azotobacter chroococcum and its nitrogen fixing potentiality. The fields in which there was judicious use of chemical fertilizers along with crop rotation, use of FYM, low tillage practice shows better population of the Azotobacter chroococcum as well as nitrogen fixing potentiality. Crop rotation and use of the FYM have exerted better effect on the growth and development of Azotobacter chroococcum as well as its nitrogen fixing potentiality.