盐分离子对生物炭和土壤中硅溶出的影响  

Effects of salt ions on silicon dissolution in biochar and soil

作　　者：王杰[1] 王耀锋 WANG Jie;WANG Yaofeng(College of Resources and Environment,Xinjiang Agricultural University/Key Laboratory of Soil and Plant Ecological Process,Urumqi 830052,China)

机构地区：[1]新疆农业大学资源与环境学院/新疆土壤与植物生态过程重点实验室,乌鲁木齐830052

出　　处：《农业环境科学学报》2024年第11期2680-2689,共10页Journal of Agro-Environment Science

基　　金：国家自然科学基金地区科学基金项目(42367037)。

摘　　要：为了解生物炭改良盐渍土壤中硅的溶出特征受盐分离子的影响,本试验通过制备不同温度的小麦秸秆生物炭(WS300–WS700)和棉花秸秆生物炭(CS300–CS700),研究了生物炭在不同提取剂(H_(2)O、CaCl_(2)和NaCl溶液)中硅的动力学、连续提取溶出及其对土壤中硅溶出的影响。结果表明,生物炭中硅的动力学溶出浓度在第3天达到峰值,降低后平稳波动。500℃和700℃生物炭在H_(2)O和NaCl溶液中的硅溶出量高于300℃的生物炭,小麦和棉花秸秆生物炭中硅累积溶出量均在H_(2)O溶液提取中最高,WS300在NaCl溶液中硅溶出量最低,其余生物炭均在CaCl_(2)溶液提取中最低。小麦秸秆生物炭中硅的溶出量大于棉花秸秆生物炭,H_(2)O溶液中WS700的硅累积溶出量最高为1 146.10μg,CaCl_(2)溶液提取CS300处理最低,几乎为0。生物炭添加到土壤的累积硅溶出变化趋势与生物炭单独溶出一致,H_(2)O溶液提取WS700处理的土壤硅溶出量最大,CaCl_(2)溶液提取的次之,NaCl溶液最小,这可能与土壤本身在CaCl_(2)溶液中的硅溶出量较高于NaCl溶液有关。扫描电镜能谱(SEM-EDS)和X射线衍射(XRD)表征发现,离子与可溶性硅反应并吸附于生物炭表面,可能是生物炭在盐溶液提取中硅溶出量降低的原因。生物炭用于盐渍土壤改良能够提升土壤中硅的溶出,降低盐分离子对硅溶出的抑制作用。To understand the dissolution characteristics of silicon in biochar amended saline soils as influenced by salt ions,we prepared wheat straw biochar(WS300–WS700)and cotton straw biochar(CS300–CS700)at different temperatures and investigated the kinetics of silicon in different extractants(H_(2)O,CaCl_(2),and NaCl solutions),dissolution by successive extractions,and the effect of biochar on the dissolution of silicon in soil.We observed that the kinetic dissolved concentration of silicon in biochar peaked on the third day,decreased,and then fluctuated steadily.Silicon dissolution in H_(2)O and NaCl solutions was higher in biochar prepared at 500℃and 700℃than in biochar prepared at 300℃.The cumulative dissolution of silicon in all wheat and cotton straw biochar was highest with H_(2)O solution extraction,whereas biochar silicon dissolution was lowest and almost zero with CaCl_(2) solution extraction,except for WS300.More silicon was leached from wheat straw biochar than from cotton straw biochar.In the H_(2)O solution,WS700 showed the highest cumulative silicon dissolution of 1146.10μg,while CS300 leached the lowest amount in CaCl_(2) solution extracts.Trends in cumulative leaching of silicon from biochar-treated soils were consistent with biochar:soil silicon dissolution was greatest from the WS700 treatment extracted in H_(2)O solution,followed by the CaCl_(2) solution extraction and least in NaCl solution.This could be attributed to the soil itself having a higher dissolution of silicon in the CaCl_(2) solution than in the NaCl solution.Scanning Electron Microscopy-Energy-Dispersive X-Ray(SEM-EDS)and X-ray Diffraction(XRD)characterization revealed that the decrease in silicon dissolution from biochar in saline extraction may be due to the reaction of ions with soluble silicon, which is subsequently adsorbed onto the biochar surface. Biochar for saline soil amendment increasessilicon dissolution in soil and reduces inhibition of silicon dissolution by salt ions.

关 键 词：生物炭 硅溶出 提取剂 盐分离子 

分 类 号：S156.4[农业科学—土壤学]