有机硅改性复合肥防治水稻镉污染的效果和初步机制

Effect and Preliminary Mechanism of Rice Cadmium Control by Silicone Modified Compound Fertilizers

为探讨有机硅改性复合肥防治水稻镉(Cd)污染的效果和机制,采用田间小区试验和大面积示范试验,研究不同配比的有机硅改性复合肥及其不同用量对水稻镉含量、养分吸收、产量和土壤镉有效性及其形态变化的影响。结果表明,小区试验中,与CK和CF1相比,施用有机硅改性复合肥降低了水稻分蘖期茎叶部和根部镉含量,分别下降57.0%~64.1%和24.0%~65.4%;与CK相比,成熟期茎叶镉含量降低30.1%~74.3%,稻米镉含量下降65.3%~81.1%。该结果在大面积示范中得到验证,与普通复合肥相比,有机硅改性复合肥降低了44.2%~86.0%的稻米镉含量,基本达到稻米食用安全国家标准;增加水稻对氮、磷、钾、铁的吸收;增产12.1%~20.0%;土壤pH值提高0.07~0.47;有效镉含量下降1.9%~14.3%。小区试验土壤镉形态分析表明,与CK和CF1相比,有机硅改性复合肥处理的交换态镉含量下降1.2%~22.3%、还原态镉含量增加6.1%~43.0%、氧化态镉含量下降6.8%~35.0%、残渣态镉含量增加2.2%~60.0%。综上所述,施用有机硅改性复合肥可以提高水稻养分吸收,增加水稻产量,同时降低水稻对镉的吸收转运,是一项水稻镉污染防治的新技术。

In order to explore effect and mechanism of organosilicon modified compound fertilizers on remediation of cadmium(Cd)pollution in rice,a field plot experiment and demonstration experiments was conducted to study the Cd contents,nutrient absorption,rice yield as well as the availability and transformation of soil Cd under the treatments of organosilicon modified compound fertilizers with different proportions and dosages.The results showed that compared with CK and CF1,the Cd contents in the shoot and root at the tillering stage decreased by 57.0%~64.1%and 24.0%~65.4%,respectively,and compared with CK,the Cd contents in shoot and grain at mature stage decreased by 30.1%~74.3%and 65.3%~81.1%in the plot experiment.The results were verified in the field demonstration experiment.The Cd contents in rice grain decreased by 44.2%~86.0%,meeting the national rice safety standard.In addition,organosilicon modified compound fertilizers increased the uptake of N,P,K and Fe.The yield increased by 12.1%~20.0%,soil pH increased by 0.07~0.47.The analysis of soil Cd showed that the available Cd contents decreased by 1.9%~14.3%.Similarly,the exchangeable Cd form decreased by 1.2%~22.3%with the reduced state increased by 6.1%~43.0%,the oxidizable form decreased by 6.8%~35.0%and the residue form increased by 2.2%~60.0%in the plot experiment.In summary,the application of organosilicon modified compound fertilizers could improve nutrient uptake of rice,increase yield,reduce Cd uptake and transport of rice and would be a new technology for Cd remediation in rice.