Effects of basal and foliar selenium fertilizers in reducing cadmium and increasing selenium in selenium-enriched,cadmium-polluted rice fields
To investigate the effects of basal and foliar selenium fertilizers in reducing cadmium and increasing selenium in rice grown in selenium-enriched soil with mild cadmium contamination,in the present study,the yield of rice in the maturity stage,contents of cadmium and selenium in various tissues,enrichment and transport coefficients,and morphology of cadmium in the soil were determined and analyzed using field experiments.Three treatments(viz.,basal selenium fertilizer,foliar selenium fertilizer,and basal selenium fertilizer+foliar selenium fertilizer)were investigated,with conventional fertilizer application used as the control.The results showed that the foliar selenium fertilizer significantly increased rice yield.After application of the basal selenium fertilizer,the soil pH value rose by 0.19 units,an increase of 3.01%.The basal selenium fertilizer also reduced the weak acid extractable state of cadmium in the soil at a rate of 2.96%,promoting the transition of cadmium from the weak acid extractable state to the oxidizable and residual states,thereby reducing the effectiveness of the heavy metal in the soil.The foliar selenium fertilizer significantly reduced the cadmium transfer coefficient of rice,especially from straw to brown rice,with a reduction rate of 15.13%.Additionally,it improved the selenium transfer coefficient of rice,especially from root to straw,with an increase rate of 18.69%.Under the different selenium fertilizer treatments,the cadmium content in brown rice ranged from 0.159 mg·kg-1 to 0.183 mg·kg-1 and the selenium content ranged from 0.216 mg·kg-1 to 0.244 mg·kg-1.The different selenium fertilizer treatments were able to achieve the effects of reducing cadmium and enhancing selenium in brown rice,with the foliar selenium fertilizer producing better effects than the basal selenium fertilizer.The effects were the best when both fertilizers were used simultaneously,whereupon the cadmium content in brown rice was reduced by 26.39%and the selenium content was enhanced by 41.50%.It can be seen that in selenium-rich soil with mild cadmium contamination,either the basal selenium fertilizer or foliar selenium fertilizer can effectively reduce the cadmium content in rice grains and improve their enrichment of selenium,with the simultaneous application of both fertilizers yielding the best results.In conclusion,the simultaneous application of the two selenium fertilizers yields the best combination of reducing the cadmium content and increasing the selenium content in brown rice.
riceselenium fertilizationcadmiumtransport and accumulation
万方数据
维普
