Abstract:

Spraying foliar fertilizer and applying soil conditioner are the main measures to control polluted paddy fields at present. The better effect for paddy fields with different pollution types and pollution levels for the foliar inhibitor and soil conditionerare the research focus. Field experiments were conducted to study the effect of inorganic silicon foliar fertilizer and soil conditioner on moderate and severe lead and cadmium resistance of rice in polluted paddy fields in 2019. Three treatments, conventional fertilization treatment as control (CK), conventional fertilization with spraying inorganic silicon foliar fertilizer treatment (L-Si), conventional fertilization with inorganic silicon soil conditioner treatment (S-Si), were carried out. The results showed that the contents of plumbum in the soil treated with L-Si was higher than that of the control (116.00±4.35) mg∙kg^-1 up to 18.97%. Compared with the control (5.51±0.06), S-Si treatment could increase the pH value of paddy soil by 0.73, plumbum and cadmium in the soil are 12.07% and 14.81% higher than the control (116.00±4.35) mg∙kg^-1, (1.89±0.03) mg∙kg^-1 significantly. The enrichment of plumbum in root, leaves and rice treated with L-Si decreased by 11.69%, 12.40% and 38.46% respectively compared with the control. The contents of cadmium in rice leaves, rice hulls and rice decreased by 18.10%, 5.84% and 40.84% compared with the controlsignificantly. The enrichment of plumbum in root, stem, leaf, rice husk and rice treated with S-Si was significantly reduced by 11.69%, 36.93%, 15.16%, 23.47% and 51.28% compared with the control. Cadmium concentration in roots, stems, leaves, rice hulls and rice decreased by 12.93%, 42.28%, 61.75%, 59.85% and 49.21% respectively. Compared with the control (7052.27±95.07) kg∙km^-2, the rice yield treated with L-Si and S-Si increased about 3.24% and 4.09%. It follows that the accumulation of plumbum in leaves is reduced while lead absorption in soil by roots is reduced, and plumbum absorbed by roots is enriched in stems and rice hulls after inorganic silicon is absorbed by leaves. While the cadmium accumulation in leaves were reduce, and it did not reduce cadmium absorption by root system, and accumulated cadmium absorbed by root system in roots and stems. Moreover, inorganic silicon soil conditioner not only fixes plumbum and cadmium in the soil, but also blocks the absorption of lead and cadmium by rice roots. So the contents of plumbum and cadmium in rice roots, stems, leaves, rice hulls and rice are reduced significantly.

Key words: inorganic silicon, rice, plumbum, cadmium

摘要：

喷施叶面阻控剂和施用土壤调理剂是目前污染稻田治理的主要措施,针对不同污染类型、污染程度稻田研发效果较好的叶面阻控剂及土壤调理剂是研究重点。文章通过2019年的田间试验研究无机硅叶面肥及土壤调理剂对中重度铅镉复合污染稻田水稻铅镉阻控效果。共设3个处理：常规施肥处理（CK）、常规施肥+喷施无机硅叶面肥处理（L-Si）、常规施肥+施用无机硅土壤调理剂处理（S-Si）。结果表明：L-Si处理土壤中铅质量分数较对照 (116.00±4.35) mg∙kg^-1高18.97%;S-Si处理较对照 (5.51±0.06) 能够显著提高稻田土壤pH值0.73,土壤中铅和镉分别较对照 (116.00±4.35)、(1.89±0.03) mg∙kg^-1高12.07%和14.81%。L-Si处理下铅在根、叶片、稻米中富集较对照分别减少11.69%、12.40%和38.46%;镉在叶片、稻壳、稻米中较对照显著减少了18.10%、5.84%和40.84%。而S-Si处理中铅在根、茎、叶、稻壳、稻米中富集量较对照显著减少11.69%、36.93%、15.16%、23.47%和51.28%;镉在根、茎、叶、稻壳、稻米中富集量显著降低12.93%、42.28%、61.75%、59.85%和49.21%。L-Si及S-Si处理水稻产量较对照 (7052.27±95.07) kg∙hm^-2分别提高3.24%和4.09%。综上所述,无机硅经叶面吸收后,在减少叶片中铅富集的同时减少了根系对土壤铅的吸收,将经根系吸收的铅富集于茎和稻壳中;而在减少叶片中镉富集的同时并未减少根系对镉吸收,将经根系吸收的镉富集于根和茎中。无机硅土壤调理剂在将土壤中铅和镉固定于土壤中的同时阻隔了水稻根系对铅和镉下吸收,因此水稻根、茎、叶、稻壳、稻米中铅和镉的含量均显著降低。

关键词: 无机硅, 水稻, 铅, 镉