生物炭与叶面硒肥联合施用对生菜吸收镉及土壤镉形态的影响  

Effects of Combined Application of Biochar and Foliar Selenium Spray on Cd Uptake by Lettuce and Cd Forms in Soil

作　　者：罗盼军 马倩倩 武均[1,2] 许旺旺 马文军 蔡立群[1,2] LUO Pan-jun;MA Qian-qian;WU Jun;XU Wang-wang;MA Wen-jun;CAI Li-qun(Collge of Resources and Environmental Sciences,Gansu Agricutural University,Lanzhou 730070,China;Gansu Provincial Key Laboratory of Arid Land Crop Science,Gansu Agricultural University,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学资源与环境学院,甘肃兰州730070 [2]甘肃农业大学甘肃省干旱生境作物学重点实验室,甘肃兰州730070

出　　处：《土壤通报》2022年第4期956-964,共9页Chinese Journal of Soil Science

摘　　要：【目的】为探明生菜吸收富集镉的能力对生物炭与叶面硒肥的响应程度,抑制有毒有害元素镉的吸收。【方法】通过盆栽试验,以生菜为研究对象,在镉污染土壤中添加生物炭,并在生菜叶片上喷硒处理,探索了生物炭与叶面喷硒的联合施用对镉污染土壤理化指标(pH和有机碳)和土壤不同形态镉含量以及对生菜镉吸收累积的影响。【结果】(1)土壤中添加生物炭与叶面硒肥都可以有效降低生菜可食部镉含量,其中喷施低浓度硒的效果更好。当生物炭添加量为30g kg^(-1),叶面喷硒浓度为1 mg L^(-1)时,生菜地上部镉含量由0.314 mg kg^(-1)降至0.049 mg kg^(-1),低于国家食品安全标准(GB 2762—2017)中规定的叶菜类镉限量值0.20 mg kg^(-1)。(2)镉胁迫下,添加生物炭与叶面硒肥的交互作用对生菜镉含量和镉富集与转运能力均产生了显著性的影响,相对于生菜根部镉含量,添加生物炭的效应高于叶面硒肥的效应,而对于地上部镉含量,叶面硒肥的效应高于添加生物炭的效应。(3)生物炭添加可通过改善土壤pH和有机碳含量降低酸可提取态、可还原态、可氧化态镉的比例,增加残渣态镉的比例,从而有效地降低生菜对土壤中镉的吸收累积,减少生菜中镉含量。【结论】综合来看,生物炭与叶面硒肥联合施用可以降低生菜镉含量,其效果明显高于两者单独施用的效果,为无公害蔬菜的种植提供理论指导。[Objective] In order to find out the response degree of lettuce absorbing cadmium(Cd) to biochar and foliar spraying selenium, the absorption of Cd by lettuce and the forms of Cd in soil are needed to be clarified.[Method] A pot experiment was conducted to study the effects of biochar and foliar spraying selenium on the absorption and accumulation of Cd in lettuce, the effects of combined application of biochar and foliar spraying selenium on soil physical and chemical indices(pH and organic carbon), Cd content of different soil forms and Cd uptake were studied. [Result] The results showed that:(1) Adding biochar to soil and spraying selenium on leaves effectively reduced Cd content in edible part of lettuce, among which spraying low concentration selenium has better effect. When the amount of biochar was 30 g kgand the concentration of selenium sprayed on leaves was 1 mg L^(-1),the Cd content in lettuce shoots decreased from 0.314 mg kg^(-1)to 0.049 mg kg^(-1), which was lower than the limit of 0.20mg kg^(-1)for leafy vegetables stipulated in the National Food Safety Standard(GB 2762—2017).(2) Under Cd stress,the interaction between biochar and foliar sprayed selenium has a significant impact on Cd content and Cd accumulation and transportation ability of lettuce. Compared with the Cd content in lettuce roots, the effect of biochar was higher than that of foliar sprayed selenium, while the effect of foliar sprayed selenium is higher than that of biochar for the Cd content in shoot.(3) The addition of biochar reduced the proportion of acid extractable, reducible and oxidizable Cd and increase the proportion of residual Cd by changing the soil pH and organic carbon content, thus effectively reducing the Cd absorption and enrichment by lettuce. [Conclusion] The combined application of biochar and foliar sprayed selenium can reduce the Cd content of lettuce and provide theoretical guidance for the cultivation of pollution-free vegetables.

关 键 词：镉 生物炭 叶面硒肥 生菜 土壤 

分 类 号：X173[环境科学与工程—环境科学] S636.2[农业科学—蔬菜学]