不同性质硅肥影响土壤生物有效态镉砷的主要因素  

Primary Factors Affecting Soil Bioavailable Cadmium and Asenic by Different Properties of Silicon Fertilizer

作　　者：黄蕊 魏维 谢运河[2,3,4] 柳赛花 陈豪宇 彭华 纪雄辉[1,2,3,4] HUANG Rui;WEI Wei;XIE Yun-he;LIU Sai-hua;CHEN Hao-yu;PENG Hua;JI Xiong-hui(Longping Branch of Graduate School of Hunan University,Changsha 410125,China;Hunan Institute of Agro-Environment and Ecology,Hunan Academy of Agricultural Sciences,Changsha 410125,China;Ministry of Agriculture Key Laboratory of Agriculture Environment in Middle Reach Plain of Yangtze River,Changsha 410125,China;Key Laboratory of Prevention,Control and Remediation of Soil Heavy Metal Pollution in Hunan Province,Changsha 410125,China)

机构地区：[1]湖南大学研究生院隆平分院,长沙410125 [2]湖南省农业科学院湖南省农业环境生态研究所,长沙410125 [3]农业部长江中游平原农业环境重点实验室,长沙410125 [4]稻田土壤重金属污染防控与修复湖南省重点实验室,长沙410125

出　　处：《环境科学》2023年第2期991-1002,共12页Environmental Science

基　　金：国家自然科学联合基金项目(U21A20291);国家自然科学基金项目(42007118);湖南省自然科学基金青年基金项目(2020JJ5297);湖南省农业科技创新资金项目(2020CX54)。

摘　　要：为研究硅肥影响土壤中生物有效态镉(Cd)和砷(As)的主要因素,选择不同性质的3种碱性硅肥[Na_(2)SiO_(3)、 CaSiO_(3)与ASSF (pH 9~11)]和一种弱酸偏中性可溶硅肥(NSSF,pH 5~6)并通过添加不同用量硅肥(25~800 mg·kg^(-1),以Si计)开展室内土盆试验,淹水共育21 d后对土壤基本理化性质进行检测,同时利用薄膜扩散梯度(DGT)提取土壤生物有效态Cd和As.结果表明,不同性质硅肥施用对土壤基本理化性质的影响差异显著,具体来说:3种碱性硅肥均显著提升土壤pH值(P<0.05),其中Na_(2)SiO_(3)提升土壤pH能力最强;而NSSF的施用则显著降低土壤pH值但提升了土壤Eh值(P<0.05),每单位质量(mg) Si添加量的NSSF可使土壤pH下降0.001 7个单位;在Si添加量达到400 mg·kg^(-1)后,3种碱性硅肥和NSSF土壤pH和Eh变化都趋于平缓.4种不同性质硅肥提升土壤有效硅含量能力为:NSSF>Na_(2)SiO_(3)>ASSF>CaSiO_(3).3种碱性硅肥可显著降低土壤DGT-Cd浓度而提高土壤DGT-As浓度(P<0.05),但是在CaSiO_(3)添加量为100 mg·kg^(-1)(以Si计)时,可以在显著降土壤DGT-Cd浓度的同时(降低约50.89%)又不引起DGT-As浓度大幅度上升;而NSSF使得土壤DGT-As浓度显著降低,土壤DGT-Cd浓度显著增加(P<0.05),Si添加量为400 mg·kg^(-1)时,土壤DGT-As浓度基本达到稳定状态,降As率达85.87%.对影响DGT-Cd和DGT-As浓度因素进行相关性分析,发现土壤pH是影响DGT-Cd浓度和DGT-As浓度的主要因素,其次是土壤Eh;土壤有效硅与土壤有效磷本身对土壤Cd和As生物有效性影响可忽略不计;施用碱性硅肥当土壤pH为6.5~7.0时,土壤DGT-Cd浓度基本达到最低值;而施用NSSF使得土壤pH为5~5.5时,DGT-As浓度基本达到最低值.明确硅肥降低土壤中生物有效态Cd和As主要影响因素对确保农业绿色发展以及促进粮食安全生产有重要的指导意义.To clarify the primary factors affecting soil bioavailable cadmium(Cd) and arsenic(As) by silicon fertilizer,we chose different properties of silicon fertilizer,including three types of alkaline silicon fertilizer [Na_(2)SiO_(3),CaSiO_(3),and ASSF(pH 9-11)] and one weak acid neutral soluble silicon fertilizer(NSSF,pH 5-6),to carry out a pot experiment by adding different amounts of Si fertilizer(25-800 mg·kg^(-1),calculated as Si).After 21 days of flooding,soil basic physical and chemical properties,along with diffusive gradients in thin film Cd and As(DGT-Cd and DGT-As) were investigated.The results showed that the application of Si fertilizer with different properties had different significant effects on the basic physical and chemical properties of soil.Specifically,the three types of alkaline silicon fertilizer significantly increased the soil pH(PNa_(2)SiO_(3)>ASSF>CaSiO_(3).Additionally,the application of the three types of alkaline silicon fertilizer apparently decreased soil DGT-Cd while increasing soil DGT-As(P<0.05).When the addition rate of CaSiO_(3) was up to 100 mg·kg^(-1)(calculated as Si),soil DGT-Cd concentration could be significantly decreased by approximately 50.89% without causing a significant increase in soil DGT-As concentration.Conversely,when the NSSF application rate was up to 400 mg·kg^(-1)(calculated as Si),the soil DGT-As basically reached its steady-state,and the DGT-As reduction rate reached 85.87%.Strikingly,the correlation analysis of the influencing factors of soil DGT-Cd and DGT-As showed that soil pH was the main factor affecting soil bioavailable Cd and As(DGT-Cd and DGT-As),and the effect of soil available Si and P on soil Cd and As bioavailability was negligible.Consequently,soil DGT-Cd and soil DGT-As could reach a minimum when soil pH was adjusted to 6.5-7.0 or 5-5.5 by alkaline silicon fertilizer or NSSF,respectively.It is undoubtedly of great significance,to clarify the primary factors that influence soil bioavailable Cd and As to ensure food security production.

关 键 词：不同性质硅肥 土壤镉(Cd)和砷(As) 生物有效态 影响因素 

分 类 号：X171.5[环境科学与工程—环境科学]