贵州省黔南州耕地土壤硒地球化学特征及富硒资源评价

Geochemical Characteristics of Selenium in Cultivated Soil and Evaluation of Selenium Rich Resources in Qiannan Prefecture in Guizhou Province

摘要:

通过对黔南州耕地土壤和农作物及其配套根系土调查，全州共采集了49281件表层土壤、975件农作物及其配套根系土945件，主要分析了土壤和农作物Se元素。分析结果表明，黔南州耕地土壤中硒的含量变化范围为0.02～19.20mg/kg，平均含量为0.57mg/kg，其背景值高于贵州省耕地土壤和全国表层土壤背景值；耕地土壤中硒元素含量主要受成土母岩影响，土壤类型、土地利用方式和酸碱度对其产生一定影响。研究区内圈定富硒耕地土壤资源面积达3700km2以上，占黔南州参与评价地类面积的72%以上，全州富硒耕地土壤资源主要集中在福泉市、瓮安县、长顺县、龙里县、贵定县和惠水县内。黔南州富硒农产品种类丰富，其中大宗农作物玉米、特色农作物中的高钙苹果、刺梨、蜜柚果皮、辣椒、西红柿、莴笋、紫王葡萄富硒率均超过了80%以上；而全州农作物对土壤中硒的平均富集系数不到7%，这说明农作物中硒含量水平还受土壤的理化性质、硒的赋存形式、农作物类型和农作物不同部位等因素的影响。本研究成果对于黔南州富硒产业发展以及农业规划提供了地球化学数据支撑。

Abstract:

Through investigation of farmland soil, crops and their supporting root systems in Qiannan Prefecture, a total of 49281 surface soil samples and 975 crops and their supporting root systems soil samples have been collected throughout the prefecture. Se element in the soil and crops has been mainly analyzed. It is showed that the variation range of selenium content in cultivated soil in Qiannan Prefecture is 0.02~19.20mg/kg, with an average content of 0.57mg/kg. Its background value is higher than that of cultivated soil in Guizhou province and national surface soil background value. The selenium content in cultivated soil is mainly significantly affected by the parent rock of the soil, and soil type, land use mode, and pH have a certain impact on it. The designated area of selenium rich cultivated land soil resources is over 3700km2, and accounts for over 72% of the evaluated land area in Qiannan Prefecture. The selenium rich cultivated land soil resources in the entire prefecture are mainly concentrated in Fuquan city, Weng'an county, Changshun county, Longli county, Guiding county and Huishui county. Qiannan Prefecture has a rich variety of selenium rich agricultural products, with a selenium rich rate of over 80% for bulk crops, such as corn, high calcium apples, prickly pears, pomelo peels, chili peppers, tomatoes, lettuce, and purple king grapes. The average enrichment coefficient of selenium in soil by crops in the entire state is less than 7%. It is indicated that the selenium content level in crops is also influenced by factors, such as soil physicochemical properties, selenium occurrence forms, crop types, and different parts of crops. This study will provide geochemical data support for the development of selenium rich industry and agricultural planning in Qiannan Prefecture.