施磷对土壤硒形态及小麦硒吸收转运的影响

发布时间：2018-02-28 05:52

本文关键词： 磷土壤小麦亚硒酸盐硒酸盐　出处：《石河子大学》2017年硕士论文　论文类型：学位论文

【摘要】：【目的】硒是人体和动物所必须的微量元素之一,提高土壤中硒有效性是增加粮食作物中硒含量的有效途径。因此本研究通过采样调查与盆栽实验结合,分析影响土壤硒有效性的因素,研究磷素与不同价态硒配施及施用四种不同磷源对土壤硒生物有效性的影响,阐明施磷对土壤硒形态及小麦硒吸收转运的影响,为提高土壤中硒的利用率提供理论依据。【方法】小麦盆栽试验包括:(1)磷、硒配施试验:试验包含3个因素,施磷量(以P2O5计)设三个水平,不施磷(0 g/kg)、低磷(1 g/kg)、高磷(2 g/kg),磷源选用磷酸一铵(NH4H2PO4);硒源选用两种不同价态硒(亚硒酸钠Na2SeO3,硒酸钠Na2SeO4),施硒量设三个水平,不施硒(0 mg/kg)、低硒(1 mg/kg)、高硒(2 mg/kg),共18个处理。(2)不同磷源试验:磷源选用磷酸一铵NH4H2PO4,磷酸二铵(NH4)2HPO4,磷酸脲CO(NH2)2·H3PO4,聚磷酸铵(NH4PO3)n四种不同磷源,施用量1 g/kg,不施磷作为对照(CK)处理。【主要结果】(1)北疆小麦地耕层土壤全硒含量在0.144-1.153 mg/kg之间;土壤有效硒含量在17.47-84.09ug/kg之间;小麦籽粒全硒含量在0.008-0.055 mg/kg之间;小麦籽粒全硒含量与土壤有效硒含量呈显著正相关,与土壤全硒含量无显著相关性;土壤有效硒含量与土壤pH值及速效磷含量呈显著正相关性;。(2)亚硒酸盐与磷肥配施时,随着施磷量的增加土壤中可溶态硒及可交换态硒含量显著降低,土壤中铁氧化物态硒与有机态硒含量在不施硒(0 mg/kg)处理中随着施磷量的增加显著降低;相反施硒处理土壤中铁氧化物态硒与有机态硒含量随着施磷量的增加显著增加;在等施硒条件下,高磷(2 g/kg)处理显著降低小麦硒利用率,而低磷(1 g/kg)处理对小麦硒利用率无显著影响;在低硒(1 mg/kg)与高硒(2 mg/kg)处理下,较不施磷(0 g/kg)处理,高磷(2 g/kg)处理小麦肥利用率分别降低50.7%,55.6%,因此小麦各器官硒含量随着施磷量的增加而显著降低,且在高硒(2 mg/kg)条件下降幅最大,低磷(1 g/kg)处理小麦根,茎,叶及穗的硒含量较不施磷(0 g/kg)处理分别降低33.3%,34.5%,51.6%,34.3%与;高磷(2 g/kg)处理小麦根,茎,叶及穗的硒含量较不施磷(0g/kg)处理分别降低71.3%,72.1%,80.6%,73.8%;(3)硒酸盐与磷肥配施时,随着施磷量的增加土壤中可溶态硒,可交换态硒,铁氧化物态硒及有机态硒含量显著降低;小麦硒利用率随着施磷量的增加而显著提高,在施硒(低硒,高硒)条件下,较不施磷处理,施磷处理(低磷,高磷)的小麦硒肥利用率分别提高了96%,128%与78%,123%,因此小麦各器官硒含量随着施磷量的增加而显著增加,且在低硒(1 mg/kg)条件下,高磷(2 g/kg)的处理小麦根,茎,叶及穗的硒含量增加幅度最大,较不施磷处理分别增加了23.0%,17.0%,64.6%和62.1%;(4)施用磷酸一铵与磷酸二铵处理可显著降低土壤中可交换态硒,铁氧化物态硒及有机态硒含量,其中磷酸二铵处理土壤中可交换态硒,铁氧化物态硒及有机态硒含量降幅最大,在两种不同硒含量(0.308 mg/kg,1.153 mg/kg)土壤中,较不施磷处理,磷酸二铵处理土壤中可交换态硒含量分别降低17.3%与22.8%;铁氧化物态硒含量分别降低11.1%与18.5%;有机态硒含量分别降低18.5%与21.8%;磷酸脲与聚磷酸铵处理对土壤中不同形态硒含量无显著影响。(5)施用磷酸一铵与磷酸二铵显著提高小麦各器官硒含量,在硒含量为1.153 mg/kg的土壤中,施用磷酸一铵与磷酸二铵较不施磷处理小麦根部硒含量分别提高79%与81%;茎部硒含量分别提高86.6%与81%;叶部硒含量分别提高68.6%与81.8%;穗部硒含量分别提高123.5%与176.5%;在硒含量为0.308 mg/kg的土壤中施用磷酸一铵与磷酸二铵较不施磷处理小麦根部硒含量分别提高53.3%与66.7%;茎部硒含量分别提高85.7%与157.1%;叶部硒含量分别提高30.4%与53.6%;穗部硒含量分别提高138.9%与222.2%;磷酸脲与聚磷酸铵处理对小麦各器官硒含量无显著影响。【结论】磷素促进外源亚硒酸盐施入土壤后转化成难以被植物吸收的稳定态硒,因此降低了亚硒酸盐的生物有效性,外源硒为硒酸盐时,施磷降低土壤对硒酸盐的吸附,并活化土壤中稳定态硒转化成能够被植物直接吸收利用的有效态硒,提高硒酸盐的生物有效性;土壤中施用磷酸一铵与磷酸二铵显著降低土壤中可交换态硒,铁氧化物态硒及有机态硒含量,从而提高小麦各器官硒含量及小麦硒利用率;而施用磷酸脲与聚磷酸铵对土壤不同形态硒含量及小麦各器官硒含量无显著影响,因此在提高土壤硒有效性方面,施用磷酸一铵与磷酸二铵效果好于磷酸脲与聚磷酸铵。
[Abstract]:The effects of different phosphorus sources on the selenium content in soil were studied by sampling survey and pot experiment . The effects of phosphorus on the selenium content in soil and the effect of four different phosphorus sources on the biological effectiveness of Se in soil were analyzed . The results showed that the total Se content of wheat in North Xinjiang was 0.144 - 1.153 mg / kg , the effective selenium content of wheat was between 17.47 - 84.09ug / kg , the total Se content of wheat was about 0.008 - 0.055 mg / kg , the total Se content of wheat was significantly positively correlated with the content of effective selenium in the soil , and the content of effective selenium in the soil was positively correlated with the soil pH value and the content of available phosphorus . ( 2 ) The content of Se and Se in the soil was significantly decreased with increasing amount of P . The content of Se and Se in the soil decreased by 50.7 % and 55.6 % , respectively , and the Se content of wheat roots , stem , leaf and ear decreased by 71.3 % and 72.1 % respectively at high Se ( 2 mg / kg ) . The contents of Se , Se , Se and Se in the soil were significantly increased with the increase of the amount of phosphorus applied . The content of Se in the exchangeable Se , Fe and Se in the soil was increased by 23 % , 17 % , 64 6 % and 62.1 % respectively . The content of Se in leaves of wheat was increased by 85.6 % and 87.2 % , respectively . The content of Se in leaves increased by 85.6 % and 87.2 % , respectively . The content of Se in leaves increased by 86.9 % and 82.2 % , respectively .

【学位授予单位】：石河子大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S512.1;S158.3

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