The experiments were done to investigate the effect of soil pH and organic matter content on EDTAextractable
heavy metal contents in soils and heavy metal concentrations in rice straw and grains. EDTAextractable
Cr contents in soils and concentrations in rice tissues were negatively correlated with soil pH,
but positively correlated with organic matter content. The combination of soil pH and organic matter
content would produce the more precise regression models for estimation of EDTA-Cu, Pb and Zn
contents in soils, demonstrating the distinct effect of the two factors on the availability of these heavy
metals in soils. Soil pH greatly affected heavy metal concentrations in rice plants. Furthermore, inclusion
of other soil properties in the stepwise regression analysis improved the regression models for predicting
straw Fe and grain Zn concentrations, indicating that other soil properties should be taken into
consideration for precise predicting of heavy metal concentrations in rice plants.