Effect of P solubilizing bacteria and P fertilizer on inorganic P fractions of acid soil and its influence on P uptake in groundnut (Arachis hypogaea L)

The present study described the influence of Bacillus amyloliquefaciens CTC12 (KT633845) and Burkholderia cepacia KHD08 (KT717633) in combination with inorganic P fertilizer (SSP) on the inorganic P fractions (Ca-P and non occluded Al-P and Fe-P) in an acid agricultural soil. Though not significant but the highest available phosphorus was found with the combined application of 75 per cent P as SSP and inoculum KHD08 at 75 days after sowing (DAS) and harvest. Non-occluded Al-P and Fe-P accounted for maximum inorganic P fraction. Plots receiving 100 per cent single super phosphate (SSP) either sole or in combination with PSB recorded maximum non occluded Al-P and Fe-P and Ca-P. Sole application of Bacillus amyloliquefaciens CTC12 or Burkholderia cepacia KHD08 reduced the concentration of non occluded Al-P and Fe-P as well as Ca-P. The application of P solubilizing bacteria least influenced soil pH and organic carbon. However, combined application of P solubilizing bacteria and single super phosphate positively influenced pod yield and kernel P uptake. The beneficial effect of these rhizo-bacteria can be effectively used as bioinoculants combined with lower doses of inorganic P fertilizer in problematic acid agricultural soils in order to enhance crop productivity and soil available P.