云南省思茅区有机茶园土壤肥力与生态风险评估

Assessment of soil fertility and ecological risk on organic tea plantations in Simao District, Yunnan Province

  • 摘要: 明确有机茶园土壤养分状况及重金属含量,可为有机茶园土壤养分管理、肥力提升和生态风险预警提供科学依据。本研究采集了云南省普洱市思茅区7个主要产茶乡镇共72个有机茶园土壤样品,检测了铬、铅、砷、锌、铜、汞、镉、镍8种重金属含量,分析了土壤pH、有机质、全氮、有效磷、速效钾、阳离子交换量6种土壤养分指标。结果显示,思茅区有机茶园土壤pH值平均值为4.44,37.5%的样点茶园处于Ⅰ级优质标准;茶园土壤的有机质、全氮、有效磷等指标高于优质标准;应用土壤肥力综合指数(IFI)对有机茶园土壤养分状况及肥力质量进行综合评价发现,IFI值范围在0.25 ~ 1.00之间,平均值为0.66,分别有22.2%、68.1%样点的茶园处于I、II级优质标准,优良率达90.3%;土壤中重金属镉、铜、铅、铬、汞、砷、锌和镍的平均含量分别为0.14 mg∙kg−1、13.8 mg∙kg−1、16.4 mg∙kg−1、39.5 mg∙kg−1、0.03 mg∙kg−1、14.3 mg∙kg−1、38.4 mg∙kg−1和16.0 mg∙kg−1,运用Hakanson潜在生态风险指数法(RI)评估发现RI最大值为245.0,最小值为46.3,平均值为91.15(<150)。思茅区有机茶园整体土壤养分状况优良,土壤肥力综合指数较高,部分有机茶园土壤酸化严重,综合潜在生态风险指数较低。

     

    Abstract: Clarifying the nutrient status and heavy metal content of soil in organic tea gardens can provide a scientific basis for soil nutrient management, fertility improvement, and ecological risk warning in organic tea plantations. In this study, soil samples were collected from 72 organic tea plantations in seven major tea-producing townships in Simao District, Pu'er City, Yunnan Province; the contents of eight heavy metals, including chromium, lead, arsenic, zinc, copper, mercury, cadmium and nickel were determined; and six soil nutrient parameters, including soil pH, organic matter, total nitrogen, available phosphorus, available potassium and cation exchange capacity were analyzed. The results showed that the average value of soil pH of organic tea plantations in Simao District is 4.44, and 37.5% of soils are in Grade I quality standard. The indexes of organic matter, total nitrogen, and available phosphorus of soils are higher than the quality standard. Furthermore, the application of the soil Integrated Fertility Index (IFI) for the comprehensive evaluation of soil nutrient status and fertility quality revealed that the IFI value ranges from 0.25 to 1.00 with an average of 0.66, 22.2%, and 68.1% of the tea gardens soils belongs to Class I, II quality standard, and the excellent rate is 90.3%. The average levels of Cd, Cu, Pb, Cr, Hg, As, Zn, and Ni in the soil are 0.14 mg∙kg−1, 13.8 mg∙kg−1, 16.4 mg∙kg−1, 39.5 mg∙kg−1, 0.03 mg∙kg−1, 14.3 mg∙kg−1, 38.4 mg∙kg−1, and 16.0 mg∙kg−1, respectively. The maximum and minimum values of Hakanson potential ecological risk index (RI) are 245.0 and 46.3 respectively, and the mean value is 91.2 (<150). The overall soil nutrient status of the organic tea gardens is excellent with a high IFI for soil fertility and a low RI for potential ecological risk though some areas have serious soil acidification.

     

/

返回文章
返回