恩施川续断根的含硒量及其与土壤性质的关系

Selenium content of Dipsacus asper roots in Enshi area and its relation to soil properties

为了认识恩施川续断的含硒量状况及其与土壤性质和养分含量的关系,在恩施川续断生长地采集川续断和土壤样品,分析川续断根的含硒量、土壤含硒量、土壤pH、土壤有机质、总氮、碱解氮、铵态氮、硝态氮、总磷、速效磷和速效钾含量.结果表明,恩施川续断根的含硒量在0. 02 94. 88 mg kg^(-1)之间,最高值是最低值的3 271. 5倍,土壤含硒量在0. 5 277. 4 mg kg^(-1)之间,最高值是最低值的488. 2倍.川续断根的含硒量与土壤含硒量和有机质含量具有很高的相关性,其中线性、二次函数和对数相关性均达到了极显著水平.川续断含硒量与土壤pH呈极显著的二次函数相关,其余相关性均不显著.在与土壤养分的相关关系中,川续断根含硒量与土壤总磷和速效磷相关性最高,线性、二次函数和对数相关性均达到了极显著水平.川续断根含硒量与各形态氮的相关性不同,与总氮、水解有机氮的相关性差,只有二次函数相关性显著,与无机氮、碱解氮、硝态氮和铵态氮的相关性较高,二次函数相关性均达到了极显著水平.川续断根含硒量与土壤速效钾含量没有显著相关性.总之,恩施川续断能吸收利用土壤中的硒,可在含硒量高达近300 mg kg^(-1)的土壤中正常生长,说明川续断具有很强的耐受硒的能力,应该属于聚硒植物,川续断根的含硒量与土壤性质和养分的相关性和程度随土壤性质类型和养分形态不同而异,因此一般仅用线性关系分析植物组成与土壤性质和养分的关系是不充分的.

The content of selenium,soil pH,organic matter,total N,alkali-hydrolysable N,ammonium N,nitrate N,total P,available P and available K in the samples of Dipsacus asper roots and soils from Enshi area were determined to understand the content of Dipsacus asper and its relation to soil properties and soil nutrients.The results showed that the selenium content in Dipsacus asper roots and soils was in the range of 0.02 94.88 and 0.5 277.4 mg kg-1 and the highest content was 3 271.5 and 488.2 times as the lowest content,respectively.The selenium content of Dipsacus asper roots was significant positively correlated to soil selenium content and soil organic matter content,and the linear,quadratic and logarithmic relativity was strongly significant(P<0.01).There was a very significant quadratic correlation between the selenium content in Dipsacus asper roots and soil pH.Among the relationship of selenium content of Dipsacus asper roots with soil nutrient elements,with the highest relativity to soil total P and available P,the linear,quadratic and logarithmic relativity was very significant(P<0.01).The relativity of selenium content in Dipsacus asper roots to soil nitrogen content varied with the nitrogen forms.Varying with soil nitrogen forms,the relativities of selenium content in Dipsacus asper roots to soil inorganic N,alkali-hydrolysable N,nitrate N and ammonium N were stronger than to soil total N,hydrolysable organic N.The correlation of selenium content in Dipsacus asper roots to soil available K was insignificant.In summary,with the ability to accumulate soil selenium,grow normally in soil contented about 300 mg kg-1 of selenium,and tolerate high selenium environment,Dipsacus asper in Enshi area should be selenium accumulation plant,and the degree and type of correlation of selenium content in Dipsacus asper roots to soil properties and nutrients changed with the type and forms of soil properties and nutrients.It was inadequate that only the linear correlation was used to analysis the relationship of the pant composition to soil properties and nutrients.