不同浓度镉水灌溉对土壤及水稻品质的影响

Influence from Irrigation of Different Cadmium Water Density on Soil and Rice Quality

通过桶栽土培水稻试验研究不同浓度(0.04,0.08,0.10,0.12,0.20,0.24mg/L)镉水灌溉对土壤及水稻产量和品质的影响。结果表明,重金属Cd主要累积在5-20cm土层,对水稻的株高有明显的抑制作用,对千粒重也有影响,但对水稻的每穗粒数及单株产量无明显影响。不同浓度镉水灌溉对稻米的外观品质、碾米品质有一定的抑制作用,但均能达绿色大米标准;营养品质则不受影响,6个处理下蛋白质、直链淀粉含量均能达标,且与CK无差异。土壤中的Cd含量随着镉水浓度的增大而增大,稻米中的Cd含量也与镉水浓度成正比。镉水中的大部分Cd残留在土壤中,6个处理下残留量分别为99.3%,73.8%,60.4%,55.5%,37.4%,47.6%,由此可见,镉水浓度越小,土壤对Cd的吸收能力越强,镉水浓度越大,土壤对Cd的吸收能力越弱。当镉水浓度大于0.20mg/L时,精米中的Cd含量达到了限量标准值(0.2mg/kg),说明灌溉水中的重金属Cd的浓度应该控制在0.20mg/L以下。

This authors,aims at researching the influence from irrigation of different Cd water density（0.04,0.08,0.10,0.12,0.20,0.24 mg/L） on rice quality and soil through barrel plant and soil culture.Compared to CK,it showed that,Cd mainly stayed at the depth of 5-20 cm of the soil and that the density of Cd obviously restrained the stem length of rice and 1000-grain weight decreased.However,there were no obvious effects on number of grain per ear and yield per plant.Though different Cd water density restrained the appearance of rice and milling quality,these features could achieve the green rice requirement,and nutritional quality was of no affection,protein and amylose content could reach the standard and there was no difference compared to CK.The higher irrigation density was,the more Cd would stay in soil,and so did Cd in rice.Most of the Cd would remain in soil after irrigating,the detains was 99.3%,73.8%,60.4%,55.5%,37.4%,47.6%.According to these data,it could be concluded that the lower density of Cd in water used for irrigation,the more Cd would be absorbed by soil,and the higher density was,the less would be absorbed.When Cd desity was higher than 0.20 mg/L,the content of Cd in white rice reached its standard（0.2 mg/kg）,which meant that density of Cd in water used for irrigation should be lower than 0.20 mg/L.