紫云英淹水腐解各形态锌的变化  

Changes of zinc forms in the decomposition of Astragalus sinicus under waterlogged incubation conditions

作　　者：杨曾平[1] 饶中秀 李万明 谢坚[1] 李海露[1] 褚飞[1] YANG Zengping;RAO Zhongxiu;LI Wanming;XIE Jian;LI Hailu;CHU Fei(Hunan Soil and Fertilizer Institute,Changsha 410125,Hunan,China)

机构地区：[1]湖南省土壤肥料研究所,湖南长沙410125

出　　处：《草业科学》2025年第2期278-287,共10页Pratacultural Science

基　　金：国家自然科学基金联合基金项目(U21A20294);湖南省自然科学基金项目(2019JJ40168)。

摘　　要：为探究紫云英(Astragalus sinicus)在石英砂中淹水腐解对锌形态变化及有效性的影响,通过90 d室内培养试验,设置不添加紫云英(CK)和4个不同紫云英添加量(1.50、2.25、3.00和3.75 t·hm^(-2),分别用S_(1)、S_(2)、S_(3)、S_(4)表示)共5个处理,定期采集石英砂样品,测定不同形态锌和有效锌(DTPA-Zn)含量及pH。结果表明:紫云英淹水腐解能提高石英砂DTPA-Zn、交换态(Ex-Zn)、碳酸盐结合态(Carb-Zn)、氧化锰结合态(OxMn-Zn)、紧结有机态(Sbo-Zn)锌含量,降低松结有机态锌(Wbo-Zn)含量;石英砂中锌主要以Sbo-Zn和Ex-Zn存在,残渣态锌(Min-Zn)未检出;随淹水时间延长,添加紫云英促进Wbo-Zn向Sbo-Zn、Carb-Zn、OxMn-Zn转化,随紫云英添加量增多,转化为OxMn-Zn的量大于转化为Carb-Zn的量。石英砂Zn平均转化比率在S_(2)处理最低(30.9%),S_(4)处理最高(35.9%)。到试验结束,添加紫云英降低石英砂Zn转移因子,S_(3)处理最低(43.70%);提高Zn分配指数,S_(2)处理最高(37.17%);表明石英砂中Zn向无效态组分发生转化。研究表明:紫云英淹水腐解1个月石英砂Ex-Zn含量最高,随着时间延长,添加紫云英促进石英砂有效性较高锌形态向有效性较低锌形态转化,紫云英腐解3个月,石英砂Sbo-Zn含量最高。不同紫云英添加量,石英砂锌有效性和形态转化之间存在差异,添加2.25 t·hm^(-2)紫云英石英砂锌有效性下降最多。A 90-day indoor cultivation experiment investigated how the decomposition of Chinese milk vetch(Astragalus sinicus)under waterlogged incubation conditions in quartz sand affects the medium’s zinc forms and their availability.Five treatments,including a control(no A.sinicus added)and four A.sinicus treatments[at 1.50(S_(1)),2.25(S_(2)),3.00(S_(3)),and 3.75(S_(4))t·ha^(−1)]were set up.Sand samples were regularly collected to determine the pH value and contents of various zinc forms and plant-available zinc(DTPA-Zn).We found that the DTPA-Zn,exchangeable(Ex-Zn),carbonate-bound(Carb-Zn),manganese oxide-bound(OxMn-Zn),and tightly bound organic(Sbo-Zn)zinc contents increased,whereas the loosely bound organic zinc(Wbo-Zn)content decreased with the decomposition of A.sinicus under waterlogged conditions.Zinc occurred mainly as Sbo-Zn and Ex-Zn.Residual zinc(Min-Zn)was not detected.Adding A.sinicus promoted the transformation of Wbo-Zn into Sbo-Zn,Carb-Zn,and OxMn-Zn over time.Increasing the amount of A.sinicus favored the conversion to OxMn-Zn over Carb-Zn.The average Zn conversion rate was lowest in S_(2)(30.9%)and highest in S_(4)(35.9%).Adding A.sinicus reduced the Zn migration factor(S_(3)had the lowest;43.70%)and increased the Zn distribution index(S_(2)had the highest;37.17%)by the end of the experiment.This indicates the transformation of Zn into less available forms.The Ex-Zn content peaked after one month of decomposition.After that,further decomposition promoted the conversion of highly available zinc forms into less available ones.After three months of decomposition,the Sbo-Zn content was the highest.Zinc availability and transformation varied with the amount of A.sinicus added;applying 2.25 t·ha^(−1)resulted in the greatest decline in Zn availability by the end of the experiment.

关 键 词：锌形态 绿肥 室内培养 石英砂 锌转化比率 锌转移因子 锌分配指数 

分 类 号：S55[农业科学—作物学]