S. Mishra et al., A STUDY ON THE UPTAKE OF TRIVALENT AND HEXAVALENT CHROMIUM BY PADDY (ORYZA-SATIVA) - POSSIBLE CHEMICAL MODIFICATIONS IN RHIZOSPHERE, Agriculture, ecosystems & environment, 62(1), 1997, pp. 53-58
The uptake and translocation of chromium by paddy (Oryza sativa L. Arb
ario) was studied using radiotracers. Chromium was supplied as Cr III
and Cr VI through irrigation water and plants were grown in sand and s
oil culture. The uptake of chromium for both the oxidation states and
culture types was found to increase more or less linearly with the inc
rease in chromium concentration though with different slopes. The rate
of increase of the uptake when compared to the increase in feed conce
ntration indicates that the uptake by roots is mediated possibly throu
gh a passive mechanism. For a given concentration of feed, values of c
hromium in mu g g(-1) dry matter in shoot and grain did not vary signi
ficantly either for different oxidation states of feed chromium or cul
ture type. The order of uptake for paddy shows a considerably differen
t pattern when compared to onion, maize and groundnut. This has been q
ualitatively explained on the basis of the different chemistry of chro
mium in the rhizosphere of paddy. The amount of chromium translocated
to grain was also considerably less compared to the other three crops.