A glasshouse experiment was carried out to investigate the influence
of Zinc (Zn) enriched organics and Zn solubilizing bacteria on use efficiency
of Zn by turmeric crop and its availability and distribution among various
fractions of Zn in the soil using
$^{65}$
Zn isotope. The
profound effect of zinc solubilizing bacteria (ZSB) on the increase of dry
matter yield of turmeric was found to be 14.0, 14.3 and 18.1 per cent for
ZnSO
$_4$
, Zn enriched FYM and Zn enriched coirpith along with
ZSB respectively than consecutive treatments without the organism. In the pot
experiment involving
$^{65}$
Zn isotope, the specific activity,
per cent Zn derived from fertilizer Zn and uptake of Zn from applied fertilizer
and zinc use efficiency were increased intensely with the zinc enrichment
treatments than the direct Zn soil application. The zinc use efficiency
increased with the Zn treatments, where Zn enriched coirpith performed best
(3.48% in whole plant) than remaining treatments and ZnSO
$_4$
alone (0.99% in whole plant). The organic and exchangeable fractions of Zn
revealed the superior nature of Zn fortified with coirpith treatment which
surpassed the remaining treatments with its highest specific activity followed
by the treatments that received Zn or Fe or Zn + Fe fortified coirpith/FYM
than the per se application of ZnSO
$_4$
or
FeSO
$_4$
. The per cent distribution of applied Zn fertilizer
into the different forms in the soil based on specific activity of Zn to total
fraction was in the order of Organic bound Zn > Exchangeable Zn >
Manganese oxide bound Zn > Amorphous iron oxide bound Zn > Crystalline
iron oxide bound Zn. The tune of increase seen for the per se effect of Zn
solubilizing bacteria was markedly higher for organic Zn fraction for the
addition of Zn fortified FYM as well as coirpith followed by exchangeable Zn
and DTPA Zn.
