Besides the presence of naturally occurring primordial radionuclides at varying levels in soils, the source of additional natural radioactivity content in agricultural land soils is mainly due to the presence of NORM in the fertilizers. Natural Radioactivity content is determined in ten different types of fertilizers available in Villupuram District, Tamilnadu State and influence of these, if any, in fertilized agricultural soil samples is investigated and compared with virgin soil samples from nearby agricultural land where fertilizers were not used. Relatively higher radioactivity content of 238 U and 40 K are observed in single super phosphate and potash fertilizers respectively.

中文翻译：

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肥料对印度泰米尔纳德邦 Villupuram 区农田土壤样品自然放射性特征的影响

除了土壤中存在不同水平的天然原始放射性核素外，农田土壤中额外天然放射性含量的来源主要是由于肥料中存在 NORM。确定了泰米尔纳德邦 Villupuram 区可用的 10 种不同类型肥料的天然放射性含量，并调查了这些肥料（如果有）对施肥农业土壤样品的影响，并与附近未使用肥料的农田的原始土壤样品进行比较。分别在单一的过磷酸钙和钾肥中观察到相对较高的放射性含量，分别为 238 U 和 40 K。