喀斯特区不同果园土壤有效态微量元素特征变化

为正确评价喀斯特区土壤肥力状况,合理施用微量元素肥料及有效利用土壤资源,以FAST(大射电)核心区西番莲、猕猴桃、八月瓜、冷饭团4种果园为研究对象,采集0~20 cm、20~40 cm土层土壤,分析土壤有效态微量元素(Fe、Mn、Cu、Zn)含量,并根据土壤有效态微量元素含量及评价标准,评定土壤微量元素丰缺状况。结果表明,在4种果园中,土壤有效Fe、Mn、Cu、Zn含量变化分别为33.02~88.15 mg·kg^-1、5.40~15.42 mg·kg^-1、0.15~0.69 mg·kg^-1、0.28~0.84 mg·kg^(^-1),且0~20 cm土层土壤有效态微量元素显著高于20~40 cm土层;根据土壤有效态微量元素含量及评价标准,土壤有效Fe含量最高,达到极高水平,土壤有效Zn含量最低,处于极低水平;土壤微量元素有效性指数大小顺序表现为:Fe(7.98)>Cu(2.24)>Mn(1.05)>Zn(0.55)。喀斯特区土壤微量元素总体表现出有效Fe、Mn、Cu含量大于临界值,能维持植物的正常生长;土壤有效Zn含量严重低于临界值,表现出亏缺状态,在植物生长过程中应及时补充。

Characteristics of Available Contents of Soil Microelements underDifferent Land Use Patterns in Karst Area

To provide a theoretical basis for the correct evaluation of soil fertility and production conditions,rational application of micronutrient fertilizers and effective utilization and exploitation of soil resources in Karst area.The available content of soil samples with 0-20 cm and 20-40 cm depth from four typical soil plots of Passion,Kiwi,Holboellia,Kadsura in FAST core area of Guizhou was determined and then the abundance and deficiency of soil microelements were evaluated in soils was statistically analyzed by using the available microelements content and evaluation criteria.The research results showed that the changes of available Fe,Mn,Cu and Zn content in soil were 33.02-88.15 mg·kg^-1,5.40^-15.42 mg·kg^(^-1),0.15-0.69 mg·kg^(^-1) and 0.28-0.84 mg·kg^(^-1),respectively.And the available microelements in 0-20 cm soil layer were significantly higher than those in 20-40 cm soil layer under four different land use patterns.According to the soil available state microelements content and evaluation standards,the soil available Fe content was the highest,reaching a very high level,while the soil available Zn content was the lowest,at a very low level;The order of soil microelements availability index was Fe(7.98)>Cu(2.24)>Mn(1.05)>Zn(0.55).The effective Fe,Mn and Cu content of soil microelements was higher than the critical value,which could maintain the normal growth of plants,but soil available Zn content was seriously lower than the critical value,showing deficiency,which should be timely supplemented in the process of plant growth in karst area.