Effect of Retaining Cd-containing Root-stubbles in Paddy-field on Cd Accumulation in Soil and Rice
This paper deals with the issues of cadmium(Cd)in rice-stubbles that were retained in paddy fields,under-lining the study of the pathways of Cd contamination and the effect of Cd-accumulation on the next-planting rice in order to control soil Cd pollution and safe rice production.A pot-experiment was thereby undertaken with Cd-contain-ing rice-stubbles set into pot soil in different cases:0.24％(SR1),0.48％(SR2)and 0.72％(SR3)(w/w),as well as control(CK).Results of the pot-experiment showed that stubbles containing Cd retained in soil had,in certain degree,an effect on promoting rice growth,meanwhile increasing Cd content in the rice;compared to CK,the highest Cd con-tent of the rice-stubble appeared in Case SR3,up 86.90％;the distribution pattern of Cd-content in different rice parts was in order of deceending magnitude:roots＞＞stems≈leaves＞seeds,with Cd concentration of seeds being within the safe edible limit;and compared to CK,rice-stubbles increased the total Cd content of soils by 13.27％～25.51％,and in Case SR3 soil's Cd content went up to the maximal value of 1.23 mg/kg.In general,the Cd-containing rice-stubbles led to the upgrading of pH and nutrient level of the soil,comparing to the control values,pH,organic matter,available nitrogen,and available potassium contained in soils increased by 0.05～0.12,8.55％～13.68％,11.24％～13.48％and 5.56％～14.16％,respectively.To sum up,Cd-containing rice-stubbles retention in paddy fields led to increases of soil nutri-ents,promoting rice growth,meantime could led to enhanced Cd accumulation of soil,resulting in a increase of Cd content in rice roots.
万方数据
维普
