淹水灌溉联合叶面阻控剂对水稻镉吸收转运的影响

Effects of Flooding Irrigation Combined with Foliar Inhibitors on the Absorption and Accumulation of Cadmium in Rice

摘要: 在益阳市赫山区某镉(Cd)污染稻田进行田间试验，探讨淹水灌溉联合叶面阻控剂的组合措施对土壤Cd有效态含量、pH值以及水稻植株各器官(根、茎、叶、谷壳和糙米) Cd吸收转运的影响。结果表明：淹水灌溉联合叶面阻控剂的组合措施可以有效降低土壤中Cd的有效性，减少水稻对Cd的吸收。在淹水灌溉和叶面阻控剂的联合处理下，土壤中的pH值与对照相比显著(P < 0.05)提高0.5个单位，土壤有效态Cd含量(DTPA-Cd)显著降低了26.2%；水稻植株的根、茎、叶、谷壳和糙米中Cd含量均显著(P < 0.05)降低，降幅分别为14.7%、37.0%、45.4%、54.5%和47.8%；而水稻产量与对照相比无明显变化。淹水灌溉联合叶面阻控剂措施还抑制了Cd向水稻各部位的转运，根–茎、茎–叶和叶–谷壳的转运系数显著(P < 0.05)降低了25.7%、39.5%和58.4%。因此，淹水灌溉联合叶面阻控剂技术措施可在不影响水稻产量的情况下，有效阻控Cd在水稻体内的迁移转运，显著降低水稻糙米对Cd的吸收。

Abstract: A field experiment was conducted in a cadmium (Cd)-contaminated paddy field in Heshan District, Yiyang City, to investigate the effects of flooding irrigation combined with foliar inhibitors on the availability of Cd in soil, soil pH and Cd uptake and translocation in various rice plant organs (roots, stems, leaves, husks and brown rice). The results indicated that: the remediation technology integrating flooding irrigation combined with foliar inhibitors effectively reduce the bioavailability of Cd in soil and decrease Cd uptake by rice plants. Under this combined treatment, soil pH increased significantly (P < 0.05) by 0.5 units compared with the control, and the soil available Cd content decreased significantly (P < 0.05) by 26.2%. The Cd contents in roots, stems, leaves, husks and brown rice were all significantly decreased (P < 0.05) by 14.7%, 37.0%, 45.4%, 54.5% and 47.8%, respectively; while no significant changes were observed in rice yield compared with the control. Furthermore, the combined treatment significantly inhibited Cd translocation to different parts of rice. The translocation factors of root-stem, stem-leaf and leaf-husk decreased significantly (P < 0.05) by 25.7%, 39.5% and 58.4%, respectively. Therefore, the technical measures of flooding irrigation combined with foliar inhibitors can effectively reduce the absorption and translocation of Cd by rice without affecting rice yield, and significantly reduce the absorption of Cd by brown rice.