不同用量腐植酸对土壤有效硒含量和硒的形态以及大蒜硒吸收的影响

摘要

采用室内土培和网室盆栽的方法,研究了不同用量的腐植酸对土壤有效硒含量和硒形态以及大蒜硒吸收规律的影响.结果表明:土壤有效硒含量随着腐植酸用量的提高而增加,20%OM处理的土壤有效硒含量(43.3~50.6μg·kg-1)>10%OM(37.6~48.8μg·kg-1)>5%OM(36.0~44.1μg·kg-1)>CK(33.0~41.5μg·kg-1).可溶态硒与土壤有机质含量的关联度最大(关联系数为0.821),其次为有机硫化物结合态硒(关联系数为0.693),铁锰氧化物结合态硒关联度最低(关联系数为0.482).随着腐植酸用量的增加,土壤有机质含量得到相应提高,土壤中有机质的含量与可溶态硒、可交换态及碳酸盐结合态硒和有机硫化物结合态硒呈显著正相关,其相关系数分别为0.963、0.962和0.906,而与其他形态的硒相关性不明显.大蒜各部位干重的硒含量为根(0.167~0.653 mg·kg-1)>茎(0.114~0.326 mg·kg-1)>叶(0.056~0.086 mg·kg-1),且4个处理大蒜鳞茎鲜重的硒含量为0.018~0.110 mg·kg-1,均达到了富硒食品标准(HB001/T—2013).%Selenium(Se)is a necessary trace element for human health. The land area deficient in Se is up to 70%in China. And also, in some Se-enriched areas, Se-rich agricultural products can't be produced, because the bioavailability of Se in soil is very low. In this paper, soil with higher Se content was collected from a Se-rich area in Fujian Province. The soil culture test and pot experiment were carried out, to study effects of different amounts of humic acid on the content of soil available Se, the distribution of soil Se forms, and its absorption charac-teristics in garlic. The results showed that, the soil available Se was improved significantly with the increase of humic acid amount(P<0.01). Contents of soil available Se were followed by 20%OM(43.3~50.6μg·kg-1)>10%OM(37.6~48.8μg·kg-1)>5%OM(37.6~48.8μg·kg-1)>CK(33.0~41.5μg·kg-1). The organic matter content was also increased with the increase of humic acid amounts. The significant positive correlations between contents of organic matter and different forms of Se in soils were found. The correlation coefficients were 0.963, 0.962and 0.906 in the water-soluble Se, exchangeble and bound to carbonates Se, and the bound to organic matter and sulfide Se, respectively. The highest correlation was found between the organic matter and water-soluble Se, with the correlation coefficient of 0.821 with grey corre-lation analysis method, following by bound to organic matter and sulfide Se (the correlation coefficient was 0.693), and the minimum value was existed in the bound to Fe-Mn oxides(0.482). Se contents in dry weight of different parts of garlic showed the order of root(0.167~0.653 mg·kg-1)>stem(0.114~0.326 mg·kg-1)>leaf(0.056~0.086 mg·kg-1). The fresh Se contents were reached the Se-rich food stan-dards(HB 001/T-2013)in all treats, from 0.018 mg·kg-1 to 0.110 mg·kg-1.