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1.
以紫甘薯为试验材料,采用盆栽试验的方法研究了基施硒酸钠[Se(VI)]和亚硒酸钠[Se(IV)]条件下,紫甘薯对外源硒的吸收累积规律,并比较了施用两种不同价态硒的紫甘薯富硒效果。结果表明:两种硒源均可显著提高紫甘薯各器官含硒量,且紫甘薯含硒量均随施硒量的增加而增大。当土壤施硒量为Se 8 mg/kg时,施用硒酸钠、亚硒酸钠收获期薯块的硒含量(干基)分别达到6.69、0.88 mg/kg。紫甘薯生育期40 d时各器官硒含量叶茎薯块,130 d时硒含量叶薯块茎。当硒酸钠施用量为Se 4 mg/kg时,紫甘薯薯块中的硒累积量最高达923.81μg/株,硒在紫甘薯块根中的分配率可达67%~70%,硒酸钠处理下,紫甘薯对硒的吸收利用率远远高于亚硒酸钠处理。综合紫甘薯含硒量和施硒量对生长的影响结果分析,施用硒酸钠和亚硒酸钠均能增加紫甘薯薯块的硒含量,紫甘薯对硒酸钠敏感性高于亚硒酸钠,生产过程中应充分考虑施用硒酸钠对作物造成的毒害。 相似文献
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采用外源硒加入土壤中得到硒污染土壤,6种有效硒的浸提剂NaHCO3、KH2PO4、K2SO4、EDTA、AB-DTPA和DTPA＋TEA＋CaCl2的最佳浸提时间和土液比进行了筛选,并通过盆栽试验对所选择的土壤有效硒浸提剂进行生物学校验,以找出石灰性土壤有效硒提取适宜的浸提剂及其浸提条件。结果表明,NaHCO3、KH2PO4、K2SO4、EDTA、AB-DTPA和DTPA＋TEA＋CaCl26种浸提剂有效硒浸提量都随着浸提土液比的减小而增大,且随浸提时间的增长而增大。其中NaHCO3和KH2PO4最佳土液比为1/15,振荡时间90min;K2SO4和AB-DTPA的最佳土液比为1/15,振荡时间60min;EDTA和DTPA＋TEA＋CaCl2的最佳土液比则为1/20,振荡时间30min。6种浸提剂在各自最佳的提取条件下提取的土壤有效硒量与白菜地上部分硒含量达极显著正相关,但土壤有效硒的提取量以DTPA＋TEA＋CaCl2及K2SO4最少,只占KH2PO4、AB-DTPA及EDTA提取量的14%～48%,故不适用于作为石灰性土壤有效硒的提取剂。NaHCO3适用于土壤硒含量高于5mg·kg^-1的石灰性土壤有效硒提取。KH2PO4、AB-DTPA及EDTA3种浸提剂既可提取土壤中水溶态硒,亦可提取部分的吸附态硒,提取硒数量较多,过程简单,重复性好,都可作为石灰性土壤有效硒提取的浸提剂。 相似文献
3.
青海东部农田土壤硒分布特征及其影响因素 总被引：2，自引：2，他引：0
植物中硒被认为是人体摄入硒的主要来源,而且大多数植物是从土壤中吸收硒。因此,不同地区土壤硒含量的高低直接影响到该地区食物中的硒含量。本研究以青海省平安地区农田土壤为研究对象,用原子荧光光谱法进行了土壤全硒含量和形态及价态的测定,对平安地区农田土壤全硒含量分布特征及其与成土母质、土壤类型的关系进行了研究。结果表明,平安地区土壤全硒含量变化范围为0.089~0.782 mg/kg,平均值为0.418 mg/kg,其中58%的土壤属于富硒土壤范畴。研究区域耕种淡栗钙土全硒含量最高,平均值为0.574 mg/kg;而灌淤黄土全硒含量最低,平均值为0.293 mg/kg。成土母质中,古近–新近系西宁群红色泥岩中硒含量最高,平均值为0.82 mg/kg。平安地区富硒土壤中硒的富集主要来源于古近–新近系西宁群红色泥岩风化。土壤中硒的赋存形态主要以有机结合态为主,铁锰氧化物结合态硒含量最少。可溶态硒和可交换态及碳酸盐结合态硒均以六价硒为主要赋存价态。平安地区富硒土壤中硒含量适宜,供硒潜力较大,且该地区受外界环境污染较少,具有良好的开发利用前景。 相似文献
4.
硒高/低累积型水稻富硒特征的比较研究 总被引：2，自引：0，他引：2
《土壤通报》2017,(4):943-947
通过盆栽试验分析硒高、低累积型水稻植株硒的吸收和分配规律、糙米中有机硒的累积特点及土壤有效硒的变化。结果表明:两个水稻品种各部分硒的分配规律完全一致,均为根茎叶糙米稻壳。水稻各部分的含硒量及糙米有机硒的含量均随土壤施硒水平增加而升高,且高累积水稻的含硒量显著高于低累积水稻(P0.05),在0、0.5、1.0和5.0 mg kg-1施硒水平下,前者分别为后者的6.7、1.9、2.1和1.6倍。糙米中有机硒的比例为64.7%~74.4%,不过,高、低累积型水稻糙米有机硒占全硒的比例之间并无显著性差异(P0.05)。土壤总硒及有效硒的含量随施硒量的增加也表现出逐步升高的趋势,但高、低累积型水稻土壤有效硒的比例均在5.5%~7.4%范围内,且两者之间无明显差异(P0.05)。除水稻基因型外,土壤有效硒的比例对水稻籽粒有机硒的累积也有一定影响。 相似文献
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研究生物炭调理措施对红壤区富硒土壤硒形态及硒生物有效性的影响,为富硒土壤硒活化及硒资源高效利用提供理论依据。通过盆栽试验,连续开展三批玉米苗期研究,设置3个生物炭添加水平：土壤质量0.5%(T1)、1.0%(T2)和1.5%(T3),以不添加生物炭处理为对照（CK）,分析生物炭添加对土壤硒形态及玉米硒素营养的影响。结果表明：施用生物炭后,T1、T2和T3的可溶态硒分别平均提高0.46、0.42和0.43个百分点;可交换态硒分别平均提高0.61、1.66和1.50个百分点;降低了铁锰氧化物结合态硒的比例;有机结合态硒比例先降低后逐渐提高,残渣态硒比例则先提高后逐渐降低。玉米根系硒含量与土壤可溶态、可交换态及有效硒含量均呈显著线性正相关,玉米茎叶硒含量与土壤各硒形态之间的相关性不显著。施用生物炭能提高玉米植株体内的硒累积量,T1、T2和T3处理玉米植株平均硒累积量分别比CK提高9.46%、31.00%和21.22%。可见,在红壤上施用生物炭能有效提高土壤硒的生物有效性并促进硒在植物体内的累积,其中以添加土壤质量1.0%的生物炭效果最好。 相似文献
6.
探讨叶面喷施和土施外源硒对芒果叶片和果实硒含量、果实矿质元素含量及营养品质的影响,以期为富硒芒果的安全生产提供理论依据和技术支持。以“桂热 82号”芒果为试材,叶面喷施以亚硒酸钠为硒源,设置0.0、25.0、50.0、100.0、150.0和 200.0 mg/L 6个浓度水平,于生理落果结束后,每 15 d喷施一次,连喷 2次。土施设置亚硒酸钠处理和硒酸钠处理,施肥量为 10 g/株,于花期沟施。结果表明,芒果叶片和果实中的硒含量随着叶面喷硒浓度的增加而递增。叶面喷施 50 mg/L亚硒酸钠可显著提高果实 Vc含量,200 mg/L亚硒酸钠可显著提高果实K、可滴定酸含量,100～ 200 mg/L亚硒酸钠可显著降低果实Zn、Ca含量。土施相同量的亚硒酸钠和硒酸钠均可显著提高芒果叶片和果实硒含量。土施硒酸钠叶片和果实硒含量显著高于亚硒酸钠。土施 10 g/株亚硒酸钠显著降低果实 Ca、Mg含量,土施 10 g/株硒酸钠显著提高果实 K、Vc含量,降低果实 Ca含量。叶面喷硒和土壤施硒均可显著提高芒果叶片和果实硒含量,其中叶面喷硒提高幅度远大于土壤施硒提高幅度。土施硒酸钠比亚硒酸钠更容易被芒果吸收。富硒芒果生产上推荐叶面喷施 25.0～ 50.0 mg/L亚硒酸钠,或者土施 10 g/株硒酸钠。 相似文献
7.
8.
紫云英对水稻硒累积特征和糙米硒含量的影响 总被引：1，自引：0，他引：1
通过对土壤含硒量、紫云英和外源硒对水稻硒累积特征和糙米硒含量的田间小区试验研究结果表明:作物含硒量直接受土壤全硒量的影响,紫云英对土壤硒的吸收量是糙米吸收量5.13～6.07倍。增施紫云英可显著提高糙米的含硒量,施入富硒紫云英糙米含硒量为0.0910mgkg-1;施入紫云英糙米含硒量为0.0501mgkg-1。紫云英的施用量以22500mghm-2为宜。喷施适宜用量的外源硒对水稻生育性状和产量影响较小,但可迅速显著提高糙米和秸秆的含硒量,其含硒量与喷施量成正比,使无机硒的含量提高。在普通紫云英下喷施以10mgkg-1亚硒酸钠为宜,在生长期后期喷施的效果为好,其中乳熟期喷施效果更好。紫云英对水稻产量有一定的增产作用,增产幅度为2.16%～4.39%。 相似文献
9.
以大棚种植的4年生绿芦笋"井冈701"为试材,研究不同浓度的亚硒酸钠溶液的不同施用方式对芦笋含硒量和营养品质的影响。结果表明,叶面喷施和土壤浇灌两种方式对芦笋体内硒的积累呈现不同的特点,但均能显著提高总硒含量,其浓度跟施硒浓度成正相。土壤浇灌100 mg kg~(-1)亚硒酸钠溶液可使芦笋嫩茎总硒含量在2个月以上的时期内持续稳定在100μg kg~(-1)的安全范围内,效果最好。而有机硒含量随施硒浓度的增加先升高后下降。施用适当浓度的亚硒酸钠能提高芦笋嫩茎的Vc和总蛋白质含量,改善芦笋的营养品质。 相似文献
10.
若尔盖高原湿地土壤硒的数量、形态与分布 总被引：6，自引：0，他引：6
用连续浸提的方法研究了若尔盖高原4种湿地土壤(风沙土、草甸土、沼泽土和泥炭土)中硒的含量、形态、剖面分布及其影响因素,以期为该区人、畜缺硒症的防治积累科学资料。结果表明,该区土壤属于低硒环境,表层土壤全硒含量范围为65～260μg/kg。在各种形态硒中,水溶性硒仅占土壤全硒含量的1.12%～3.08%,交换态硒占2.91%～6.03%,有机态硒占10.28%～45.63%,酸溶态硒、硫化态硒和残余态硒3种无效态硒共占60%以上。在土壤有机态硒组成中,胡敏酸结合态硒(HA-Se)占有机态硒的57.84%,富里酸结合态硒(FA-Se)占42.16%。土壤总硒和有机态硒的含量与分布主要受土壤有机碳的影响,且其影响程度随着深度的不同而改变,湿地土壤丰富的有机碳有利于土壤有机态硒和总硒的积累。土壤总硒含量低、有机态硒的比例较高以及胡敏酸结合态硒占优势导致硒的生物利用率低,可能是该区域人、畜硒缺乏症发生的重要原因。 相似文献
11.
发生分类淋溶土与系统分类参比特征研究 总被引：5，自引：2，他引：5
利用最新建立的中国 1∶10 0万土壤数据库 ,研究了我国发生分类淋溶土与中国土壤系统分类的参比及其在中国土壤系统分类下的空间分布和数量特征。结果表明 ,我国发生分类淋溶土总面积为10 5 975 7.8km2 ,分布规律明显 ;与系统分类参比 ,发生分类淋溶土分属于中国土壤系统分类 4个土纲 ,即淋溶土、雏形土、新成土和灰土 ,它们分别占发生分类淋溶土总面积的 72 .8%、2 6 .1%、1.0 %、0 .1% ,其中包含系统分类的 2 5个土类和 4 7个亚类 ,参比关系复杂 ,不是简单的一对一的关系。分析发生分类某一类型土壤分属于系统分类不同类型的面积比例及其标准偏差 ,结果表明土壤参比的单元级别越低 ,越易于参比和把握。为了使中国土壤系统分类更实用、更易于普及 ,深入开展土壤基层分类研究 ,进一步发展和完善中国土壤系统分类是必要的 ,也是十分迫切的。研究结果对于土壤类型的正确参比、中国土壤系统分类的应用与发展 ,具有很好的参考应用价值 相似文献
12.
低硒土壤中75Se的形态转化 总被引：2，自引：0，他引：2
用75SeO2水溶液分别按0.131ppm和1.631ppm比例处理暗棕色森林土。用这种土壤盆栽的小麦含Se分别为0.023ppm和0.493ppm。小麦收获之后,对土壤残留的75Se用不同的提取剂连续进行化学分级,75Se的各种形态按其占土壤总Se的百分比大小排序为:同位素交换态Se>NH4OH可提态Se>HNO3可提态Se>HCl可提态硒>水溶态Se>K2SO4可提态硒。土壤残留75Se主要以NaHSeO3同位素交换态存在,其量占土壤总硒28%,NH4OH可提态Se次之,占20%;水溶态Se较少,仅6-7%。以SeO3-2形式加入土壤的75Se被土壤紧密吸附。 相似文献
14.
《Soil Science and Plant Nutrition》2013,59(3):424-433
Abstract This study aimed to clarify pedogenetic processes and classification of yellowish Brown Forest Soils according to the Classification of Forest Soils in Japan and the Yellow Brown Forest soils according to the Unified Soil Classification System of Japan in the warm and cool temperate forest of Kyushu district, Japan. In addition, the study aimed to clarify a problem with the Unified Soil Classification System of Japan. Thirty-six soil profiles of Brown Forest Soils, including 13 yellowish Brown Forest Soils and 15 Yellow Brown Forest soils, were compared with regard to their chemical properties and the relationship with climatic conditions was assessed. The yellowish Brown Forest Soils had thin A horizons, low pH and low levels of free oxides in the B horizons, and a low amount of silica and a high aluminum and iron to silica ratio. These features were related to the paleo reddish weathering. The immaturely developed A horizon of the yellowish Brown Forest Soils was caused by these weathered, low-activity substances. The Yellow Brown Forest soils had low levels of active iron oxides and a low activity ratio of free iron oxides compared with the Haplic Brown Forest soils in the same thermal climatic conditions. The activity ratio of free iron oxides was correlated to mean annual air temperature with the carbon stocks and with many other chemical properties. Accordingly, classification of Brown Forest Soils was clearer according to thermal climatic conditions. The activity ratio of free iron oxides can become an effective index that distinguishes Yellow Brown Forest soils under warm temperate lucidophyllous forest and Haplic Brown Forest soils under cool temperate broad-leaved deciduous forest with considerable vertical soil zonality. 相似文献
15.
通过用静态碱吸收法对中亚热带福建三明格氏栲自然保护区内的格氏栲天然林和33年生的格氏栲人工林及杉木人工林的土壤异养呼吸进行为期2年的定位研究。结果表明，三种森林枯枝落叶层呼吸和无根土壤呼吸速率季节变化均呈单峰曲线，最大峰值出现在5月至6月，最小值出现在12月至1月。格氏栲天然林、格氏栲人工林和杉木人工林枯枝落叶层呼吸速率平均值分别为CO2 79．88、44．37和21．02mgm^-2h^-1，无根土壤呼吸速率平均值分别为CO2 217．4、85．85和94．04mg m^-2h^-1。2002年枯枝落叶层呼吸速率和无根土壤呼吸速率主要受土壤温度影响，但在极端干旱的2003年则主要受土壤湿度的影响。双因素关系模型（R=ae^bTW^c）拟合结果优于仅考虑土壤温度或土壤湿度的单因素关系模型，土壤温度和土壤湿度共同解释不同年份枯枝落叶层呼吸和无根土壤呼吸速率季节变化的82％～85％和85％～92％。不同森林枯枝落叶层呼吸对土壤温度和湿度的敏感性均高于无根土壤呼吸的。格氏栲天然林、格氏栲人工林和杉木人工林枯枝落叶层呼吸年通量分别为C3．76、2．63和1．23t hm^-2a^-1，无根土壤呼吸年通量则分别为C3．44、2．79和1．49t hm^-2a^-1。不同森林土壤异养呼吸通量的差异主要与枯落物数量和质量、土壤有机质数量和质量的差异有关。杉木林枯枝落叶层呼吸对干旱敏感性高于格氏栲（天然林和人工林）的，而人工林（杉木和格氏栲）的土壤有机C对干旱敏感性则要高于格氏栲天然林。 相似文献
16.
Abstract Properties and classification of four selected volcanic ash soils from Abashiri, Hokkaido were studied and the transition of Andisols to Mollisols was discussed. Two of the four pedons (Brown Andosol and Cumulic Andosol)1 showed morphological, clay mineralogical, physical, and chemical properties common to most Andisols in Japan. However, the properties of the other two pedons (Acid Brown Forest soil and Brown Forest soil)1 were considerably different from those of common Andisols in Japan. It was found that the changes in the andic soil properties or transition of Andisols to Mollisols was closely related to the progression of clay weathering, mainly the transformation of noncrystalline clay materials to halloysite. One of the four pedons (Brown Forest soil)1had the clay fraction dominated by halloysite from the uppermost horizon down to the bottom of the profile and satisfied both andic and mollic requirements. Thus we concluded that the pedon is a transitional soil between Andisols and Mollisols and that the transition is closely related to the duration of surface weathering under relatively weak leaching conditions. The four pedons were classified according to the Andisol Proposal (Leamy et al. 1988, New Zealand Soil Bureau) as follows: Pedon 1: Medial, amorphic (allophane/imogolite), frigid Typic Hapludand (Brown Andosol).1 Pedon 2: Medial, amorphic (allophane/imogolite), frigid Typic Melanudand (Cumulic Andosol).1 Pedon 3: Medial, amorphic (allophane/ imogolite), over kandic, frigid Typic Melanudand (Acid Brown Forest soil).1 Pedon 4: Medial, kandic, frigid Typic Hapludand (Brown Forest soil).1 相似文献
17.
Juan Jose Rios Begoña Blasco Rocio Leyva Eva Sanchez-Rodriguez M. M. Rubio-Wilhelmi Luis Romero 《Journal of plant nutrition》2013,36(9):1344-1354
The mineral composition and maintenance of mineral balance are important to growth and development of plants. The selenium (Se) has not been described as an essential element for plants, although there are studies that have demonstrated to interaction between Se with other mineral nutrients. The aim was to evaluate the influence that Se application at different rates and forms exerts on the nutritional state in lettuce plants. The plants were grown under different treatments: 5, 10, 20, 40, 60, 80, 120 μmol L?1 as sodium selenate [Na2SeO4 or Na2SeO3]. All the plants growth under controlled conditions. The results showed changes in some of the essential nutrients inside of plants such as nitrogen (N), phosphorous (P), iron (Fe), copper (Cu), calcium (Ca). The effect of Se depended largely on the Se from was applied to the culture medium. Thus, the selenite application had a stronger effect on the nutritional state of the plant. 相似文献
18.
We examined the effects of root and litter exclusion on the rate of soil CO2 efflux and microbial biomass at a soil depth of 25 cm in a secondary forest (dominated by Tabebuia heterophylla) and a pine (Pinus caribaea) plantation in the Luquillo Experimental Forest in Puerto Rico. The experimental plots were initially established in 1990, when root, forest floor mass and new litterfall were excluded for 7 y since then. Soil respiration was significantly reduced in the litter and root exclusion plots in both the secondary forest and the pine plantation compared with the control. Root exclusion had a greater effect on soil CO2 efflux than the litter exclusion in the plantation, whereas a reversed pattern was observed in the secondary forest. The reduction of microbial biomass in the root exclusion plot was greater in the secondary forest (59%) than in the plantation (31%), while there was no difference of the reduction in the litter exclusion plots between these forests. Our results suggest that above-ground input and roots (root litter and exudates) differentially affect soil CO2 efflux under different vegetation types. 相似文献
19.
Hiroaki Kurihara Yasuo Kitagawa Shizuo Nagatsuka 《Soil Science and Plant Nutrition》2013,59(6):833-839
The activity and crystallinity ratios of free iron oxides, and the ΔlogK and RF values of humic acids were analyzed in five soil types in the Nyu mountains, Fukui Prefecture, to examine the relation between the zonality of soils and the bioclimatic conditions under the Warm-temperate deciduous broad-leaved forest climate. The characteristics of free iron oxides and humic acids were as follows: The Dark red soil, Kunimidake series was a Dark Red soil under the Cool-temperate deciduous broad-leaved forest climate; the Dry brown forest soil (reddish), Tega series was a Yellow-Brown Forest soil under the Warm-temperate deciduous broad-leaved forest climate; the Dry brown forest soil, Takasu-1 series and the Yellow soil, Yada series were Yellow-Brown Forest soils under the Warm-temperate lucidophyllous forest climate; and the Red soil, Oshibayama series and the lower parts of the Tega series were paleo-red soils. These results indicated that zonal soils under the Warm-temperate deciduous broad-leaved forest climate were Yellow-Brown Forest soils in the Nyu mountains, Fukui Prefecture. The Dark red soil, Kunimidake series corresponded to a Hyperdystri-Rhodic Cambisol of World Reference Base for Soil Resources, WRB (FAO, ISRIC, and ISSS: World Soil Resources Reports 84, 1998). The Dry brown forest soil (reddish), Tega series, the Dry brown forest soil, Takasu-1 series, and the Red soil, Oshibayama series were compared with the Hyperdystri-Chromic Cambisol (WRB). The Yellow soil, Yada series was a Hypereutri-Chromic Cambisol (WRB). 相似文献
20.
Anna Wilkinson 《Soil biology & biochemistry》2011,43(6):1350-1355
The ectomycorrhizal mycelium is a large component of boreal and temperate forest soil microbial biomass and the resulting necromass is likely to be an important source of nutrients for saprotrophic microorganisms. Here we test the effects of species richness of ectomycorrhizal mycelial biomass on short-term CO2 efflux by amending forest soil with necromass from 8 fungal species added separately and in mixtures of 2, 4 and 8 species. All additions of necromass rapidly increased soil CO2 efflux compared to unamended controls but CO2 efflux increased significantly with species richness. Efflux of CO2 did not correlate with the carbon (C) or nitrogen (N) contents or the C:N ratio of the added necromass. The study demonstrates that species diversity of dead ectomycorrhizal fungal hyphae can have important consequences for soil CO2 efflux, and suggests decomposition of hyphae is regulated by specific constituents of the nutrient pools in the necromass rather than the total quantities added. 相似文献