Soil Geochemical Characteristics And Safety Evaluation Of Panax Notoginseng Plantation

It is a great significance to explore the law of migration and accumulation of multi-elements in the rock-soil-plant(Panax notoginseng)system of Panax notoginseng plantation area,and it is also important to evaluate the safety utilization of planting soil in Panax notoginseng plantation.Two typical Panax notoginseng planting areas,Qiubei County and Wenshan County were selected as research areas.In order to determine the content of multiple elements in rocks,soil,including the soil inside the shed,the soild outside the shed and out-of-shed soil,and Panax notoginseng,rocks,soil and Panax notoginseng were collected in the field.Some parameter indicators,that involves 15 indicators of rock samples,18 indicators of soil samples,and 16 indicators of plant samples,were detected by Atomic fluorescence spectrometer and other instruments.Multivariate statistical methods were used to analyze the degree of abundance,deficiency and the migration of element content in the planting area of Panax notoginseng.And the evaluation of soil safety in Panax notoginseng was performed by using the methods of set pair analysis and the fuzzy evaluation.The results show that:1.Most of the indicators in rock,soil,and plant samples are in trace levels.There is a clear difference between the components of carbonate and the components of non-carbonate,the former is characterized by high calcium(magnesium)content and low content of other elements,the latter is the opposite,with relatively low content of calcium and magnesium but higher content of other elements.For most of indexes,the variability of the shed soil(background soil)was less-than the variability of the soil inside the shed and the soild outside the shed,which indicating that the element content developed toward unhomogenization under the influence of planting activities of Panax notoginseng.The variability of soil background values of Mn and Hg indicates the diversity of soil sources.On the whole,the element content of the stem-leaf is high than in the root's,which is in agreement with the other scholars' findings that the high content of mineral elements in the stem and leaf areas with a higher metabolism than other parts.It is shown that stems and roots of Panax notoginseng have different absorption effects on mineral elements.2.The element enrichment ability between lithosphere and soil layer presents the law of Se>Mo>B>Pb>Cu>As.And the content of these elements in the soil layer(including layers ?,?,and ?)is greater than that of the rock layer(layer ?),the enrichment of these elements may be related to the elemental differentiation caused by external forces such as eolian-water flow or wind erosion.The uniformity of the elements between adjacent soil layers is high,the stability of the enrichment(?-? and ?-?)between two adjacent layers of the soil layer is slightly different,?-? enrichment trend line is significantly more volatile than ?-?,which shows that the planting activity of Panax notoginseng makes the indicators in the soil become more or less homogeneous or evenly distributed.From the bio-absorption coefficient,the dominant component sequence of Panax notoginseng could be obtained: Cr> Mn> Zn> As> B> Pb> Cu> Mo> Se> Hg,The elements Cr,Mn,and Zn are moderately ingested,and others are weak and very weak,in Panax notoginseng plant(between root layer and stem and leaf layer),the absorption and accumulation of these elements are relatively uniform,with little difference,and the element as a whole accumulates from the underground part to the ground part.3.The evaluation of soil safety by using integrated set pair analysis and fuzzy function: the evaluation results of most indexes of most samples are at the first level,but the evaluation results of the quick-acting K,B,Zn,Cr,and pH indicators are not at the first level.In the planting of Panax notoginseng,attention should be paid to increasing the content of available K,B and Zn in the soil,controlling the Cr content in the soil,and adjusting the pH of the soil so as to improve the level of soil safety utilization.