【摘要】 针对稻田土壤重金属Cu污染问题,在翻压紫云英条件下,探究化肥与生物炭基肥配施对土壤-水稻系统Cu吸收及转运的影响。采用盆栽试验,设置5个施肥处理:对照（CK,不施肥）、常规施氮（CN）、紫云英+氮肥（CNG）、紫云英+有机肥+氮肥（CNGO）、紫云英+生物炭基肥+氮肥（CNGC）。研究了不同施肥处理对早稻五优156生长和重金属Cu吸收特性的影响。结果表明:与CN相比,CNG在无污染和污染土壤中水稻籽粒产量分别提高47.1%和50.1%;与CNG相比,CNGC在无污染和污染土壤中水稻籽粒产量分别提高4.5%和12.8%。单施化肥条件下水稻植株体中Cu的总吸收量最大,且水稻根部Cu含量最高;在污染土壤中,CNG处理下水稻糙米存在一定的重金属污染风险,而在CNGC处理下糙米中Cu含量低于相关食品卫生标准(≤10.0 mg·kg^-1)。进一步研究表明,翻压紫云英能提高Cu从根向秸秆的转运能力,而在污染土壤条件下Cu从秸秆向谷壳的转运能力会受到抑制。在污染土壤中CN处理下Cu有效态含量最高,CNGC处理比CN处理土壤Cu有效态含量降低39.4%,比CK处理降低17.6%。研究表明,翻压紫云英条件下化肥配施生物炭基肥可以提高水稻产量,抑制水稻对Cu的吸收和转运,降低水稻籽粒中Cu含量,适宜在重金属Cu污染稻田施用。更多还原

【Abstract】 To address Cu pollution in paddy field soils, we studied the effects of a chemical fertilizer combined with a biochar-based fertilizer on Cu absorption and transport in the soil-rice system under ploughed Astragalus sinicus conditions. Pot experiments were conducted with five treatment groups, including control（CK, unfertilized）, conventional nitrogen fertilizer（CN）, A. sinicus + nitrogen fertilizer（CNG）,A. sinicus + organic fertilizer + nitrogen fertilizer（CNGO）, and A. sinicus + biochar-based fertilizer + nitrogen fertilizer（CNGC）. The effects of different fertilization treatments on the growth of early-season rice, Wuyou 156, were evaluated in uncontaminated and contaminated soil, and the Cu absorption and transportation processes were examined in rice organs. The results showed that, compared with the CN treatment, the grain yield increased by 47.1% and 50.1% in uncontaminated and contaminated soil, respectively, with the CNG treatment.Compared with the CNG treatment, the CNGC treatment only increased the grain yield by 4.5% and 12.8% in uncontaminated and contaminated soil, respectively. Under the application of inorganic fertilizer, Cu concentrations were the highest in rice roots and the total absorbed Cu was also at its maximum. In contaminated soil, there was a risk of heavy metal（Cu）pollution in brown rice for the CNG treatment; however, the Cu content of brown rice for the CNGC treatment was lower than the related food hygiene standard(10.0 mg·kg^-1). Further results indicated that the Cu transporting capacity from root to straw was clearly enhanced under the conditions of ploughed A. sinicus, while the Cu transporting capacity from straw to husk was inhibited in Cu-contaminated soil. Moreover, in contaminated soil, the mass fraction of available Cu was at its maximum for the CN treatment. Compared with the CN treatment, the mass fraction of available Cu in soil for the CNGC treatment was reduced by 39.4%. Compared with the CK treatment, the mass fraction of available Cu in soil for the CNGC treatment was reduced by 17.6%. In summary, in the case of ploughed A. sinicus, a fertilization method that uses a biochar-based fertilizer combined with a chemical fertilizer not only increased rice yield but also inhibited rice Cu absorption and transportation processes, thus reducing the Cu content of rice grains. Thus, such a fertilization method could be applied for the improvement and remediation of Cu in contaminated rice soil.更多还原