Burkholderia phytofrimans PsJN assisted-Iron biofortification of rice in biochar amended pH manipulated calcareous soil

Abstract

One of the major problems associated with high pH calcareous soils is micronutrient unavailability. Paddy grown in such soils is usually low in total bio-available microelements in general, and, Iron in particular. In present study bio-available contents of iron i.e. ferritin, were enhanced by exploiting the positive interaction of plants and microbial biomass in the presence of biochar in elemental sulfur treated calcareous soil. First, pH of soil was manipulated to 6.5 units by carrying out an incubation study. Four rates i.e. 0, 1.5, 2, 2.5, 3 g kg-1 soil of elemental sulfur were used. To maximize translocation and uptake of DTPA extractable Fe i.e. 15 kgha-1iron fertilizer was applied in combination with biochar, 1% (w/w) and Burkholderiaphytofirmans PsJN inoculation. Results showed that combined application of Fe, Burkholderiaphytofermans and biochar enhanced physiology, crop stand and over all rice crop turn out in pH manipulated soil relative to control. Bio-available Fe i.e. ferritin was increased by 2.54 folds while phytate contents were reduced by 35% compared to control. Quality of grain was assessed by quantifying protein, fat, ash and crude fiber that were improved by 36%, 37%, 69% and 48% respectively in pH modified soil over control. It may be concluded that integrated use of endophytic PsJN and carbon-rich biochar in pH modified soil can be a good option for iron biofortification in rice.