青阳县富硒土壤中硒的形态与水稻富硒的相关性研究

Study of Correlation between Rice Selenium and Status of Selenium in Selenium-rich Soil in Qingyang County

通过对青阳县富硒土壤中各形态硒的含量及种植水稻中硒的含量测定,研究青阳县富硒土壤中各形态硒的赋存分布特征,探讨水稻中硒含量及分布特点,同时对土壤中各形态的硒与水稻中硒的相关性进行研究。研究结果显示:青阳县富硒土壤中各形态硒的含量差异较大,其中强有机结合态、腐殖酸态和残渣态的硒,含量较高,占到总量的10%以上;而水溶态、离子态、铁锰态、碳酸盐态的硒含量较低,占总量比例皆低于5%;研究区水稻籽粒中硒的含量均值为0.063 8 mg/kg高于全国平均水平0.032 mg/kg,达到了国家富硒水稻的标准;水稻对土壤中硒的富集利用与土壤中硒的形态关系密切,当地土壤中水溶态和腐殖酸态的硒与水稻中硒的含量呈显著相关,而其它形态的硒相关性不明显,说明水稻吸收利用的主要是土壤中水溶态与腐殖酸态的硒。据此可以通过施加有机生物质的生产措施,增大土壤腐殖酸态硒的含量,提高土壤中有效硒的供给含量,以有利于水稻对土壤中硒的吸收富集,提高水稻中硒的含量。

The distribution characteristics have been studied through contents measurement of different forms of selenium in selenium-rich soil in Qingyang County and rice grow in soil;the content and distribution characteristics of selenium in rice were studied, and the correlation between different forms of selenium in soil and selenium in rice was studied. The results show:the contents of different forms of selenium in selenium-rich soil in Qingyang County vary notably. Selenium of humic acid state, strong organic binding state and residual state have a higher relative content:all higher than 10%, while selenium of water-soluble state, ion state, iron manganese state and carbonate state have a lower relative content which are all lower than 5%. In the study area,the average content of selenium in rice is 0.063 8 mg/kg, which is higher than the national average level of 0.032 mg/kg, and have reached the national standard of selenium-rich rice. Selenium enrichment and utilization of rice highly dependent on the states of selenium:selenium contents of water-soluble state and humic acid state in soil show strong relevance to the selenium content in rice, while selenium contents of other states show no distinctive relevance to the selenium content of rice. Thus, selenium enrichment and utilization of rice as well as the selenium content in rice could be promoted by apply organic biomass which could increase the content of humic acid state selenium.