摘要
为探究有机硅肥调控土壤中的镉(Cd)活性及其对水稻吸收和转运Cd的影响,采用室内土壤培养与室外水稻盆栽试验,通过两种典型有机硅肥(OSiF18和OSiF19),系统研究其对土壤中的有效态Cd含量、土壤中Cd形态分布以及水稻对Cd吸收与转运特征的影响。结果表明:(1)与对照组相比,OSiF18和OSiF19均能降低土壤中的有效态Cd含量,反应7 d后有效态Cd含量分别降低46.9%和41.9%;(2)有机硅肥调控土壤中有效态Cd的效果受土壤pH的影响,反应初期近中性环境(pH为4~7)更有利于土壤中有效态Cd的降低,但随着反应时间延长至7 d,pH为3~5的试验组呈持续增效趋势,土壤中有效态Cd的削减率增加到41.2%~48.6%;(3)适宜的肥水固液比更有利于有机硅肥降低土壤中的有效态Cd;(4)有机硅肥促进土壤中可交换态Cd向铁锰氧化物结合态、有机物结合态和残渣态转化,从而降低土壤中Cd的生物可利用性。在水稻种植初期施加有机硅肥可有效抑制水稻对Cd的吸收与转运,富集系数BCF_(根/土壤)和转运系数TF_(籽粒/秸秆)的大小顺序均为B18>B19>KB>A19>A18(“B”为抽穗期施加硅肥,“A”为种植初期施加硅肥),而TF_(秸秆/根)的大小顺序为KB>A18>A19>B19>B18。其中,抽穗期的施硅处理虽然提高了Cd在植株内的转运能力,但不利于籽粒安全;相比之下,种植初期施加有机硅肥在降低籽粒中的Cd累积方面更具优势。有机硅肥通过调控土壤中Cd的化学形态降低其生物有效性,并有效抑制了水稻对Cd的吸收和转运,在Cd污染农田修复中具有良好的应用前景。
To investigate the effects of organosilicon fertilizers on regulating the cadmium(Cd)activity in soil and its influence on the absorption and translocation in rice,this study combined laboratory soil incubation experiments with outdoor rice pot trials.Two representative organosilicon fertilizers(OSiF18 and OSiF19)were applied to systematically evaluate their impacts on soil available Cd concentrations,Cd fraction distribution in soil,and Cd uptake and translocation characteristics in rice plants.The results showed that:(1)compared with the control group,both OSiF18 and OSiF19 significantly reduced the concentration of available Cd in soil;after 7 days of incubation,available Cd decreased by 46.9%and 41.9%,respectively.(2)The effectiveness of organosilicon fertilizers on regulating available Cd in soil was strongly influenced by soil pH.During the initial reaction stage,near-neutral conditions(pH 4~7)were more favorable to the decrease of available Cd in soil;however,as the reaction time was extended to 7 days,treatments at pH 3~5 exhibited a sustained enhancement effect,with the reduction rate of available Cd increasing to 41.2%~48.6%.(3)An appropriate fertilizer-water solid-liquid ratio was more conducive to the reduction of soil available Cd by organosilicon fertilizers.(4)Organosilicon fertilizers promoted the transformation of exchangeable Cd into iron-manganese oxide-bound,organic matter-bound,and residual fractions,thereby decreasing the bioavailability of Cd in soil.Application of organosilicon fertilizers at the early stage of rice cultivation effectively inhibited Cd uptake and translocation in rice.The order of the bioconcentration factor(BCF_(root/soil))and the translocation factor(TF_(grain/straw))was B18>B19>KB>A19>A18(where“B”denotes silicon fertilizer application at the heading stage and“A”denotes application at the early growth stage),whereas the order of TF straw/root was KB>A18>A19>B19>B18.Although silicon application at the heading stage increased cadmium translocation within the rice plant,it was unfavorable for grain safety.In contrast,silicon application at the early growth stage was more effective in reducing cadmium accumulation in rice grains.Organosilicon fertilizers significantly reduce the bioavailability of Cd by regulating its chemical speciation in soil and effectively inhibit Cd uptake and translocation in rice,demonstrating a promising potential for the remediation of Cd-contaminated agricultural soils.
作者
彭丽
龙照宇
杨玲
何钟林
郑明明
PENG Li;LONG Zhaoyu;YANG Ling;HE Zhonglin;ZHENG Mingming(School of Chemistry and Environmental Engineering,Wuhan Polytechnic University,Wuhan 430023,China)
出处
《武汉轻工大学学报》
2026年第1期99-105,119,共8页
Journal of Wuhan Polytechnic University
基金
湖北省自然科学基金联合基金项目(编号:2023AFD066).
关键词
土壤
镉
有机硅肥
水稻
吸收转运
soil
cadmium
organic silicon fertilizer
rice
uptake and transport
