【摘要】 [目的]为了研究湖北省恩施州富硒高镉土壤区土壤pH、有机质、CEC和土壤硒镉关系,揭示土壤理化性质对土壤硒镉含量的影响。[方法]以恩施州目前已经所做土地质量地球化学调查的区域,圈出富硒高镉土壤区,选择在区内采样分析的土壤数据,整理出土壤理化性质和对应的土壤硒镉元素及有效态硒镉数据,分析它们的关系及理化性质对土壤硒镉的影响。[结果]在恩施富硒高镉土壤区内,①土壤硒含量和土壤有机碳含量呈显著的正相关。第一等级有机质土壤中硒平均含量达到9.688 mg/kg,分别是第二、三、四等级的有机质土壤硒平均含量的5.32、8.8和4.67倍。②农作物根系土镉含量和土壤有机质含量呈显著的正相关,有机质第一等级的土壤中镉均值含量达到19.604 mg/kg,分别是第二、三、四等级有机质土壤镉含量的6.84、9.51和8.25倍。③土壤有效硒含量和土壤酸碱度呈显著的正相关。随着土壤的酸碱度等级上升,土壤有效态Se的含量显著上升(P=0.02968<0.05),碱性土壤区间中有效态硒均值达到26.296 ng/kg,分别是中性、微酸、酸性、强酸性土壤区间的1.51、2.86、4.62、3.63倍。④农作物根系土壤酸碱度和土壤镉含量相关性不显著。⑤土壤有效态硒含量和土壤阳离子的线性关系不显著。⑥土壤镉含量和土壤阳离子交换量的线性关系不显著。[结论]研究认为恩施富硒高镉土壤区土壤有机质、土壤酸碱度显著影响土壤硒镉含量,有效态硒在碱性土壤中显著增多,农作物富硒种植可以适当增加土壤碱性,土壤阳离子交换量CEC对土壤硒镉含量的影响有限。更多还原

【Abstract】 [Objective]In order to study the relationship between soil pH,organic matter and CEC and the soil selenium and cadmium in the selenium rich and high cadmium soil area of Enshi prefecture of Hubei province,the effect of soil physical and chemical properties on the content of selenium and cadmium in soil was revealed.[Method]The number of soil rich in selenium and high cadmium soil was circled in the area of land quality geochemistry investigation in Enshi state,and the number of soil samples analyzed in the area was selected.According to the physical and chemical properties of soil and the corresponding soil selenium and cadmium and available selenium and cadmium data,the relationship between them and the effects of physical and chemical properties on soil selenium and cadmium were analyzed.[Result]In the selenium rich and high cadmium soil region of Enshi:(i)Soil selenium content and soil organic carbon content showed significant positive correlation.The average content of selenium in the first grade organic soil reached 9.688 mg/kg,which were 5.32,8.8 and 4.67 times the average contents of selenium in organic soils of second grade,third grade and fourth grade,respectively.(ii)There was a significant positive correlation between the content of cadmium in the roots of crops and the content of soil organic matter.The mean cadmium contents in the first grade of organic matter reached19.604 mg/kg,which were 6.84,9.51 and 8.25 times the content of cadmium in second grade,third grade and fourth grade organic soils,respectively.(iii)There was a significantly positive correlation between soil available selenium content and soil pH.With the increase of soil acidity and alkalinity grade,the content of available Se in soil increased significantly(P =0.02968<0.05).The mean value of effective selenium in alkaline soil range was 26.296 ng/kg,which were 1.51,2.86,4.62 and 3.63 times of neutral,acid,acid and strong acid soils,respectively.(iv)There was no significant correlation between soil pH and soil cadmium content.(v)The linear relationship between soil available selenium content and soil cations was not significant.(vi)The linear relationship between soil cadmium content and soil cation exchange capacity was not significant.[Conclusion]Therefore,it is considered that the soil organic matter and soil acidity and alkalinity in Enshi rich selenium and high cadmium soil area have significant effects on the content of selenium and cadmium in the soil,the effective selenium in the alkaline soil increases significantly,the crop selenium planting can increase the soil alkalinity properly,and the effect of the soil cation exchange amount CEC on the soil selenium and cadmium content is limited.更多还原