以苏南典型区2 027套稻米-土壤样品的Se、Cd含量及其相关元素地球化学数据为基础，通过元素相关性统计分析及生物富集系数等分布特征研究，探讨了农田土壤中Se与Cd的拮抗作用及其控制因素。结果表明：①土壤中Se和Cd含量分布共消长特征明显，两者之间具有显著正相关性，相关系数为0.87；②有关岩石、陶瓷原料、河泥等均可成为农田富集Se、Cd的物质来源，且多为富Cd强于富Se，只有源于富硒岩石的富硒土壤才可排除Cd污染干扰，出产天然富硒食品；③稻米Se与Cd的生物富集系数多介于0.1~0.8，土壤偏碱性有利于稻籽吸收Se，偏酸性则有助于稻籽吸收Cd，受土壤Se、Cd同富集的影响，富硒米与镉超标大米可共存；④土壤富Se抑制稻米Cd吸收是有条件的，当土壤Se含量>0.4 mg/kg、总有机碳含量>15 g/kg时，稻米Cd含量与土壤Se含量、稻米Cd生物富集系数与土壤Se含量之间均存在显著负相关性，相关系数分别为-0.74、-0.56；土壤pH与稻米Cd生物富集系数、土壤总有机碳含量与稻米Se生物富集系数之间也存在显著负相关性，其相关系数分别为-0.79、-0.65。
Based on the geochemical data of Se, Cd and other elements of 2 027 rice-soil samples in the typical areas of southern Jiangsu Province, this paper discussed the antagonism and controlling factors of Se and Cd in farmland soils by statistical analysis of element correlation and distribution characteristics such as biological enrichment coefficient (BCF). The results showed that:1) The distributions of Se and Cd in soils had obvious characteristics of co-fluctuation, and significant positive correlation existed between the two elements (correlation coefficient r=0.87). 2)Rocks, ceramic raw materials, river mud and so on could be the substance sources of Se and Cd enrichment in farmland, and Cd enrichment was usually stronger than Se enrichment. Only Se-enriched soils derived from Se-enriched rocks could eliminate the interference of Cd pollution and produce natural Se-enriched foods. 3)BCFs of Se and Cd in rice were mostly between 0.1 and 0.8, alkaline soil was beneficial for rice seeds to absorb Se and acid soil was beneficial for rice seeds to absorb Cd. Under the influence of soil Se and Cd co-enrichment, rice could simultaneously be Se-enriched while Cd-excessed. 4)Soil Se-enrichment inhibited Cd uptake in rice under certain conditions, when soil Se concentration > 0.4 mg/kg and total organic carbon >15 g/kg, significant negative correlations existed between rice Cd concentration and soil Se concentration (r=-0.74), and between rice Cd BCF and soil Se concentration (r=-0.56), significant negative correlations also existed between soil pH and rice Cd BCF (r=-0.79), and between soil total organic carbon and rice Se BCF (r=-0.65).
范健,任静华,廖启林,葛礼强,徐宏婷,崔晓丹,李文博,汪子意.苏南典型区农田土壤硒-镉拮抗作用研究[J].土壤,2021,53(5):1023-1032. FANJian, REN Jinhua, LIAO Qilin, GE Liqiang, XU Hongting, CUI Xiaodan, LI Wenbo, WANG Ziyi. Antagonism Between Se and Cd in Typical Farmland Soil in Southern Jiangsu Province[J]. Soils,2021,53(5):1023-1032复制