海东市平安区土壤与农作物Se含量分布特征

为探究青海省海东市平安区的土壤及农作物的硒含量及富集特征，系统地采集分析了平安区七个乡镇152份0~50 cm深度土壤样品及1 161份植物样品，采用氢化物-原子荧光光谱法测定土壤及作物硒含量。结果表明，平安区表层硒含量平均值为0.27 mg/kg，高于全国及世界土壤硒平均值，有75.36%的地区处于适量硒状态，且三合镇的土壤硒含量最高，古城乡最低，总体上各乡镇采集的0~10 cm、10~20 cm、20~30 cm、30~50 cm土层之间的硒含量差异不显著，但随土壤深度的增加，硒含量逐渐降低。在几种作物中，油菜的平均硒含量最高，达到富硒标准，小麦、玉米、豌豆、燕麦、马铃薯硒含量平均值均达到足硒标准，青稞和蚕豆在土壤硒含量较高的三合镇达到足硒标准以上。综合分析，土壤硒含量与相应的作物籽粒硒含量呈正相关，油菜、小麦、玉米硒的富集系数较高，对硒具有良好的吸收能力，因此适宜在相应的富硒地发展富硒农产品，豌豆、蚕豆、燕麦、青稞属于中等富硒作物，马铃薯的富集系数最小而变异系数最高，适合在硒含量较高的地方种植马铃薯。

Distribution Characteristics of Selenium Content in Soil and Crops of Ping '' an District in Haidong City

To investigate the selenium content and enrichment characteristics of soil and crops in Ping ''an District, Haidong City, Qinghai Province,soil samples from 152, 0~50 cm depth and 1 161 plant samples were systematically collected and analyzed. The content of selenium in soil and crops was determined by hydride atomic fluorescence spectrometry. The results showed that the average surface selenium content in Ping ''an District was 0.27 mg/kg, which was higher than the national and world average soil selenium content. 75.36% of the areas was in the appropriate selenium state, and the soil selenium content of Sanhe Town was the highest, and that of ancient urban and rural areas was the lowest. In general, there was no significant difference in selenium content among 0~10 cm, 10~20 cm, 20~30 cm and 30~50 cm soil layers collected in each township, but the selenium content gradually decreased with the increase of soil depth. In several crops, the average selenium content in rape was the highest, reaching the standard of selenium enrichment, the average selenium content of wheat, corn, peas, oats and potatoes were up to the standard of selenium, highland barley and broad bean were up to the standard of selenium in Sanhe town, where the soil selenium content was higher. Comprehensive analysis showed that selenium content in soil was positively correlated with selenium content in seeds of corresponding crops. Rape, wheat and corn had higher selenium enrichment coefficient and good absorption capacity for selenium.Therefore, it is suitable to cultivate selenium-rich agricultural products in fields with corresponding selenium-rich levels. Peas, broad beans, oat and highland barley considered moderately selenium-rich crops, whereas potatoes exhibit the lowest enrichment coefficient and the highest variation coefficient. Hence, growing potatoes in areas with high selenium content is advisable.