富硒土壤硒形态转化的主要影响因子及对作物吸收的研究

发布时间：2018-05-28 04:26

本文选题：富硒土壤 + 土壤有效硒　；参考：《福建农林大学》2017年硕士论文

【摘要】：硒(Se)是人体14种必需的微量元素之一,硒的缺乏会引发人体机能的衰退,对健康造成不良的影响。世界上缺硒的国家众多,中国也在其中,而中国南方则有多个富硒区,土壤硒含量大于0.400 mg·kg-1,如湖北恩施,江西丰城,陕西紫阳,福建诏安,福建大田等。福建省的富硒土壤面积较大,约有3.26万平方公里。有研究表明,富硒的土壤并不一定能生产出富硒的农作物,因为硒在土壤中以多种形态存在,作物能吸收的是有效态的硒,而全硒含量高的土壤有效硒含量不一定高。土壤的pH值、水分和有机质含量等因子都能影响硒的存在形态,从而影响硒的有效性。因此,为探讨不同影响因子对作物吸收硒的影响,本论文采集了福建省富硒区的土壤进行土培和盆栽试验,研究不同的影响因子对土壤有效硒含量、硒形态以及作物吸收硒的影响,从而为富硒土壤生产富硒农作物提供一定的理论依据,除此之外,还对土壤影响因子在外源添加硒的富硒土壤中有效硒含量以及作物吸收硒的影响作了一定的补充,主要结果如下:(1)对于不同pH值处理的土壤,其有效硒含量表现为pH9.0的土壤有效硒含量(81.8～87.0 μg·kg-1)pH7.5(53.3-62.5 μg·kg-1)pH6.0(43.5～55.1 μg·kg-1)pH4.5(36.5～46.2 μg·kg-1),同时,在每个时间点的取样都显示土壤有效硒的含量与土壤pH值呈现极显著的正相关。各处理中,有机物-硫化物结合及元素态硒的含量最高,其次是铁-锰氧化物结合态硒和残渣态硒,再次是可交换态及碳酸盐结合态硒,可溶态硒的含量最低。可溶态硒和可交换态及碳酸盐结合态硒与土壤pH值呈现显著或极显著正相关,而有机物-硫化物结合及元素态硒与土壤pH值呈现显著的负相关关系,土壤pH值与铁-锰氧化物结合态硒和残渣态硒的相关性不明显,但随着土壤pH值的升高有下降的趋势。小白菜生物量、根长的大小表现为pH6.0pH7.5pH9.0pH4.5,叶面积的大小表现为 pH7.5pH6.0pH9.0pH4.5,小白菜叶片Fv/Fm值大小表现为处理pH6.0、pH7.5pH9.0pH4.5。各处理小白菜根部的含硒量都大于地上部,小白菜各部位硒含量均表现为 pH9.0pH7.5pH6.0pH4.5,处理 pH6.0、pH7.5 和 pH9.0 的小白菜根部硒含量是处理pH4.5的1.99倍、4.27倍和5.23倍,地上部的硒含量是处理PH4.5的1.80倍、3.02倍和4.53倍。此外,小白菜可食部位鲜重的含硒量为0.002～0.013 mg·kg-1,只有处理pH9.0的小白菜可食部位鲜重的含硒量达到了富硒水平。(2)对于不同干湿交替处理的土培土壤,其有效硒含量表现为CK(保持土壤含水量为田间持水量的80%)的有效硒含量(37.5～37.6μg·kg-1)T3(重干湿交替)(29.0～33.1μg·kg-1)T2(轻干湿交替)(24.9～26.8 μg·kg-1)T1(保持 1-2cm 的水层)(15.8～16.0 μg·kg-1)。对于不同干湿交替处理的水稻,其株高、分蘖数和有效穗数均表现为ck(灌浆期前淹水,灌浆期后轻干湿交替)t2(轻干湿交替)t3(重干湿交替)t1(保持1-2 cm的水层),而产量则表现为t2ckt3t1。各处理水稻不同部位的硒含量都表现为根茎叶壳米。t3处理的水稻硒含量(O.185-O.695mg·kg-1)t2(0.181-0.573 mg·kg-1)ck(0.158～0.491 mg·kg-1)t1(0.132～0.411 mg·kg-1)。另外,土壤有效硒含量与水稻各部位的含硒量呈显著或极显著正相关。(3)随腐植酸用量的增加,土壤有效硒含量也随之增加,表现为20%OM处理的有效硒含量(43.3～50.6 μg·kg-1)10%OM(37.6～48.8 μg·kg-1)5%OM(36.0～44.1μg·kg-1)CK(33.0～41.5μg·kg-1)。各处理土壤有机物-硫化物结合及元素态硒和残渣态硒占总硒的比例最高,其次是铁-锰氧化物结合态硒和可交换态及碳酸盐结合态硒,可溶态硒含量最低。土壤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物-硫化物结合及元素态硒呈现显著正相关,与铁-锰氧化物结合态硒与残渣态硒呈现负相关。以土壤有机质含量作为母序列进行的灰色关联分析也表明可溶态硒与土壤有机质的关联度最大,其次为有机物-硫化物结合及元素态硒,再次分别是可交换态及碳酸盐结合态硒、残渣态硒和铁-锰氧化物结合态硒。大蒜各部位的硒含量均表现为根茎叶,且随腐植酸用量的增加,大蒜根、茎、叶的硒含量也会增加。(4)在外源添加硒的情况下,土壤有效硒的含量也会随土壤pH值的升高而增加,均表现出SepH9.0的土壤有效硒含量SepH7.5SepH6.0SepH4.5,各处理小白菜不同部位的硒含量都表现为根地上部,小白菜各部位的硒含量均表现为SepH9.0SepH7.5SepH6.0SepH4.5,处理SepH9.0和SepH7.5的小白菜达到了富硒标准;对于不同干湿交替的处理,土壤有效硒含量表现为SeCK(保持土壤含水量为田间持水量的80%)SeT3(重干湿交替)SeT2(轻干湿交替)SeT1(保持1-2 cm的水层),各处理水稻不同部位的硒含量都表现为根茎叶壳米,水稻各部位的含硒量都表现为Set3Set2SeckSet1;随腐植酸用量的增加其土壤有效硒的含量也会升高,表现为Se20%OM的土壤有效硒含量Se10%OMSe5%OMSeCK,各处理大蒜不同部位的硒含量均表现为根茎叶,大蒜各部位的硒含量均表现为Se20%OMSe10%OMSe5%OMSeCK。另外,所有外源添加硒的处理,其土壤有效硒含量以及作物含硒量都高于无外源添加硒的处理。
[Abstract]:Selenium (Se) is one of the 14 essential trace elements in the human body. The lack of selenium may cause a decline in human function and a bad effect on health. There are many countries lacking selenium in the world and China in which there are several rich selenium areas in the south of China. The soil selenium content is more than 0.400 mg. Kg-1, such as Enshi in Hubei, Fengcheng in Jiangxi, Ziyang of Shaanxi, Fujian edict Se, Fujian Da Tian and so on. Fujian province has a large area of selenium rich soil, about 32 thousand and 600 square kilometers. Studies have shown that selenium rich soil does not necessarily produce selenium rich crops, because selenium exists in various forms in the soil, the crops can absorb the effective selenium, and the soil with high total selenium content is not necessarily high in soil selenium content. The pH value, water and organic matter content can affect the form of selenium and affect the effectiveness of selenium. Therefore, in order to explore the effect of different influence factors on the absorption of selenium in crops, this paper collected soil culture and pot experiments of soil in selenium rich areas of Fujian Province, and studied the soil effective selenium content and selenium form of different influence factors. In addition, the effect of soil influence factors on the effective selenium content in selenium enriched soils and the effect of crop selenium absorption were supplemented. The main results are as follows: (1) for soil treated with different pH values, the main results are as follows: The effective selenium content was pH9.0 soil effective selenium content (81.8 ~ 87 mu g. Kg-1) pH7.5 (53.3-62.5 mu g. Kg-1) pH6.0 (43.5 ~ 55.1 g kg-1) pH4.5 (36.5 ~ 46.2 micron G.). At the same time, the content of Available Selenium in the soil showed significant positive correlation with the value of soil. The content of compound and elemental selenium is the highest, followed by iron manganese oxide bound selenium and residue state selenium, the exchangeable state and the carbonate bound selenium, the soluble selenium content is the lowest. The soluble selenium and exchangeable state and carbonate bound selenium have significant or extremely significant correlation with the soil pH value, but the organic matter sulfides are combined with the selenium. There was a significant negative correlation between elemental selenium and soil pH value, and the correlation between soil pH value and Fe Mn oxide bound selenium and residue selenium was not obvious, but with the increase of soil pH value, the size of root length of Chinese cabbage was pH6.0pH7.5pH9.0pH4.5, and the size of leaf area was pH7.5pH6.0pH9.0pH4.5, The Fv/Fm value of the leaves of Chinese cabbage showed pH6.0, the content of selenium in the root of Brassica chinensis was greater than that in the upper part of pH7.5pH9.0pH4.5., and the selenium content in all parts of pakchoi was pH9.0pH7.5pH6.0pH4.5. The selenium content in the root of Chinese cabbage treated with pH6.0, pH7.5 and pH9.0 was 1.99 times, 4.27 times and 5.23 times of pH4.5, and the selenium content in the upper part of the ground was contained. The quantity is 1.80 times, 3.02 times and 4.53 times that of PH4.5. In addition, the selenium content of fresh weight of the edible part of Chinese cabbage is 0.002 ~ 0.013 mg kg-1. Only the selenium content of fresh weight of the edible parts of Chinese cabbage treated with pH9.0 has reached the level of selenium. (2) the effective selenium content of soil cultivated soil with different dry and wet alternate treatment is CK (keeping soil water content) The effective selenium content (37.5 ~ 37.6 mu g / kg-1) T3 (29 ~ 33.1 mu g / kg-1) T2 (24.9 to 26.8 mu g kg-1) T1 (24.9 to 26.8 mu g kg-1) T1 (15.8 to 16 mu g kg-1) (15.8 to 16 mu g kg-1). For different dry and wet rice, the height, tiller number and effective spike number of the rice were all (before the filling period) Flooding, light dry and wet alternation after filling period) T2 (light dry wet alternation) T3 (alternate wet and dry wet alternate) T1 (maintain 1-2 cm water layer), and the yield shows the selenium content of different parts of the rice treated with t2ckt3t1. (O.185-O.695mg. Kg-1) T2 (0.181-0.573 mg kg-1) (0.181-0.573 mg kg-1) (0.1 ~ 0.491) (0.1 32 ~ 0.411 mg. Kg-1). In addition, the effective selenium content in soil was significantly positively correlated with the content of selenium in various parts of rice. (3) with the increase of humic acid content, the content of effective selenium in soil also increased, showing the effective selenium content (43.3 ~ 50.6 mu g. Kg-1) 10%OM (37.6 to 48.8 mu g. Kg-1) 5%OM (36 ~ 44.1 mu g kg-1) CK (33. 0 ~ 41.5 G. Kg-1). The proportion of soil organic matter - sulfide binding, elemental selenium and residue state selenium accounted for the highest proportion of total selenium, followed by iron - manganese oxide bound selenium and exchangeable and carbonate bound selenium. Soluble selenium content was the lowest. Soil organic matter content and soluble selenium, exchangeable state and carbonate bound selenium and presence The combination of sulfides and elemental selenium showed a significant positive correlation, with a negative correlation with the Fe Mn oxide binding state selenium and the residue state selenium. The grey correlation analysis of the soil organic matter content as the parent sequence showed that the soluble selenium had the greatest correlation with the soil organic matter, followed by the organic matter sulfide binding and the elemental selenium. The second is exchangeable and carbonate bound selenium, residue state selenium and iron manganese oxide binding state selenium. The selenium content in all parts of garlic is the root and stem, and with the increase of humic acid content, the selenium content of garlic root, stem and leaf will also increase. (4) the content of effective selenium in soil will also rise with the soil pH value under the condition of adding selenium. The effective selenium content of SepH9.0 was SepH7.5SepH6.0SepH4.5, and the selenium content in different parts of the Chinese cabbage were all displayed in the upper part of the root, and the selenium content in all parts of Chinese cabbage was SepH9.0SepH7.5SepH6.0SepH4.5, and the Chinese cabbage treated with SepH9.0 and SepH7.5 reached the standard of selenium enrichment. The effective selenium content of soil is SeCK (keeping soil water content 80%) SeT3 (alternate wet dry and wet alternate) SeT2 (light dry wet alternate) SeT1 (maintaining 1-2 cm water layer), the selenium content in different parts of the rice is all expressed as root and leaf shell rice, the content of selenium in each part of water rice is Set3Set2SeckSet1; with humic acid The content of effective selenium in soil also increased, and the content of effective selenium in Se20%OM was Se10%OMSe5%OMSeCK. The selenium content in different parts of garlic were all expressed as root and stem, and the selenium content in each part of garlic showed Se20%OMSe10%OMSe5%OMSeCK., the treatment of exogenous selenium added, the effective selenium content in the soil. And the selenium content of crops is higher than that without exogenous selenium.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S158.3

【参考文献】