Foliar application of selenite and selenate to potato (Solanum tuberosum): effect of a ligand agent on selenium content of tubers

The effect of a foliar spray of selenium on potatoes was investigated for 2 years. Amounts of 0, 50, and 150 g of Se ha(-)(1) were applied both as sodium selenate and as sodium selenite in water, either pure or with the addition of 0.15% of soluble leonardite as a source of humic acids (pH 7). Tuber selenium concentration increased with the application levels, both with sodium selenate and with sodium selenite, when only aqueous solutions were used. When humic acids were added, the tuber selenium level rose more markedly after the application of sodium selenate as compared to the case of the aqueous solutions; however, in the case of sodium selenite, the level showed a large increase only after the application of 50 g of Se ha(-)(1). Kinetics showed that humic acids raised the selenate availability, but no differences were found in the distribution of selenium in the tuber fractions. Foliar application of selenium with humic acids was proven to be a good way to increase the selenium content of potatoes, but the assimilation process of selenium was simpler with selenate than with selenite.     

Effects of different application methods of selenite and selenate on selenium distribution within wheat

Abstract

The objective of this sand culture experiment was to determine how fertilization methods (i.e., fertigation rates of 0.5, 1, and 2?mg Se·pot^?1, foliar rates of 5, 10, and 20?mg Se· L^?1) and fertilizer type (i.e., selenate or selenite) affected wheat Se concentrations. The results showed that the fertigation and foliar treatments both increased wheat Se content. In the fertigation and foliar treatment total Se content of wheat was greatest in the selenate treatments. In the fertigation treatment, the Selenite had mainly accumulated in the roots, while the Selenate was majority transported to shoot. In the foliar treatment, we found that most of Se was transported to grain. In addition, the organic Se concentration was the most than other Se fractions. In conclusion, selenate was more effective than selenite in both the fertigated and the foliar application treatments. And the foliar application was better than fertigation.     

不同浓度硒肥对籼稻硒含量和产量的影响

发展富硒水稻经济效益显著。为了进一步理解籼稻组合富硒能力和产量变化规律,本研究以安康市农科所选育的优势较好的籼稻后代组合(MR、ME、MI、ML)为材料,在苗期、孕穗期和齐穗期连续喷施不同浓度的硒肥。结果表明:随着硒肥浓度增加,4个籼稻材料硒含量均出现快速增长,但后期增速减缓,富硒能力依次为:MLMRMEMI;产量随着硒肥浓度增加而增加,但是浓度过高,产量则下降,在最适硒肥浓度下,籼稻产量大小依次为:MRMLMIME。因此,籼稻后代材料MR和ML富硒能力较好,可以作为后续育种工作的重点材料。     

新疆水稻主产区土壤硒含量与水稻籽粒硒含量的相关性

对新疆水稻主产区的44个稻田耕层土壤及收获籽粒进行调查取样,结果表明:稻田13%属于足硒土壤,82%属于富硒土壤且有5%属于高硒土壤。而水稻籽粒硒含量达到国家谷物类食品富硒标准的仅有20%,水稻籽粒硒含量与稻田土壤全硒含量相关性不显著,但水稻籽粒硒含量与土壤有效硒含量呈极显著正相关,且土壤p H值及土壤有效磷含量与土壤有效硒含量呈极显著正相关,说明在新疆水稻主产区土壤有效硒含量是衡量土壤供硒潜力的有效指标,在实际生产中大部分的稻田需要通过施用适量外源硒肥来提高水稻籽粒中硒的含量。     

叶面喷施硒对水稻籽粒中硒含量及形态的影响

为研究叶面喷施氨基酸螯合硒对水稻籽粒硒含量及形态的影响,以水稻品种百香 139 为材料,通过大田试验,在水稻破口期叶面喷施不同用量的氨基酸螯合硒,并在水稻拔节孕穗期、始穗期、扬花授粉期、灌浆期、蜡熟期 5个不同生育期叶面喷施 13.5 g/hm²(以硒计)的氨基酸螯合硒,在水稻成熟期测定、分析各处理组水稻地上部不同组织器官硒含量和籽粒硒形态。结果表明,喷施外源氨基酸螯合硒可提高水稻各器官硒含量,在适量范围内水稻植株各器官硒含量随着喷硒浓度的增加而提高;水稻籽粒中硒主要以硒代蛋氨酸存在,水稻籽粒中硒代蛋氨酸含量与总硒含量的变化规律相一致。喷施氨基酸螯合硒用量为 6.75、13.5、27.0 g/hm² 时水稻籽粒中硒含量分别为 0.168、0.431、0.439 mg/kg,均达到《富硒农产品硒含量分类要求》(DB45/T 1061-2014)的要求。拔节孕穗期至灌浆期喷硒处理水稻籽粒硒含量呈现增高趋势,灌浆期喷硒处理的水稻籽粒总硒含量最高,达到 0.320 mg/kg;水稻籽粒中硒代蛋氨酸含量占总硒含量的比例为 43% ～ 91%,硒代蛋氨酸含量占总硒含量的比例由大到小依次为:拔节孕穗期 >始穗期>扬花授粉期＝灌浆期>蜡熟期,硒代蛋氨酸比例随着施硒时期越靠近水稻成熟期越低,表明水稻叶片中硒的转化时间对稻米中硒形态有显著影响,提早喷施硒有利于有机态硒的形成,提高稻米中有机态硒的比例。在硒的生物强化生产富硒水稻中,水稻破口期叶面喷施氨基酸螯合硒的最佳用量为 13.5 g/hm²,在 5 个不同生育期喷施 13.5 g/hm² 的氨基酸螯合硒均能生产出富硒大米,且最佳喷施外源硒的时期为灌浆期。     

不同价态外源硒对小白菜生长及养分吸收的影响

采用土壤外源加入两种不同价态的硒 [Se(Ⅳ)和 Se(Ⅵ)]的盆栽试验,研究了其对小白菜生长、营养元素和硒吸收的影响。结果表明,施硒对小白菜的生长均表现出低浓度(5 mg/kg)促进,高浓度(5 mg/kg)抑制趋势。Se(Ⅵ)处理小白菜地上部硒含量大于地下部;而Se(Ⅳ)处理则与Se(Ⅵ)相反。硒从根部转运到地上部的转移因子Se(Ⅵ)处理大于Se(Ⅳ)。两种价态硒处理,小白菜对氮、磷、钾、硫、镁和锌的吸收也表现出低浓度时为促进作用,高浓度为抑制作用。Se(Ⅵ)显著增加了钙的吸收,Se(Ⅳ)却无显著影响;Se(Ⅳ)和Se(Ⅵ)均能促进小白菜对铁的吸收。相同浓度下, Se(Ⅵ)对各个营养元素吸收的影响显著大于Se(Ⅳ)。综合硒对生长和养分吸收的影响看出,小白菜施硒量以Se(Ⅵ)不超过2.5 mg/kg或Se(Ⅳ)不超过5 mg/kg为宜。     

施纳米硒对小麦籽粒硒含量及其品质性状的影响

【目的】研究基施纳米硒肥对不同小麦品种籽粒百粒重、硒含量、硒形态,其他矿质元素以及面粉糊化特性的影响,为利用纳米硒肥进行小麦硒生物强化提供参考。 【方法】选择 110 份小麦品种 (系),在扬州大学农学院网室种植,采用的施肥方式为基施纳米硒肥,设每千克土施 Se 0 (CK)、100 (Se100)、150 (Se150) mg 2 次重复,随机区组设计。小麦成熟期收获籽粒,测定百粒重。利用离子发射光谱 – 原子吸收仪测定了籽粒 Se、Ca、Mg、Cu、Fe、Mn、Zn 及 S 含量。选择高硒处理中硒含量前 10 名的品种,利用 LC-UV-AFS 测定了籽粒中不同形态硒的含量。随机挑选 59 个品种并利用 RVA 仪 (快速粘度分析仪) 测定其面粉糊化特性的特征值。利用 MATLAB 和 SPSS 软件进行数据分析。 【结果】基施硒 0、100、150 mg/kg 土,小麦籽粒的百粒重均值分别为 3.78、4.11 和 3.70 g,籽粒中总硒含量分别为 2.00、12.46 和 17.35 mg/kg。籽粒中的硒主要以有机态形式存在,以硒蛋氨酸含量最多,其次是硒甲基化半胱氨酸和少量的硒半胱氨酸,无机态硒仅微量存在于极少数品种中。基施硒肥对测定的矿质元素的吸收积累既有协同也有拮抗作用,对小麦面粉的糊化特性没有显著影响。糊化特性取决于基因型,不同品种间存在极显著差异。 【结论】硒肥可以提高小麦籽粒中的硒含量,但增幅因品种而异;硒强化后籽粒中硒主要以有机态形式存在;低浓度硒处理可以提高小麦籽粒的百粒重,且不会影响小麦的面粉糊化特性。     

萌芽前叶面喷施硒酸钠提高茶叶含硒量及品质

【目的】探究在茶树不同生育时期叶面喷施不同硒肥对夏茶产量、品质及硒含量的影响,为生产富硒茶提供技术依据。【方法】田间试验在浙江嵊州进行,供试茶树品种为‘中茶108’。试验采用二因素列区设计,主处理为硒肥种类(A因素),副处理为硒肥喷施时期(B因素)。主处理设喷施清水对照(A0)、硒酸钠(A1)、亚硒酸钠(A2)和酵母硒(A3);副处理设夏茶顶芽萌发前(5月12日,B1)与1芽1叶期(5月20日,B2)两个喷施时期。硒肥喷施浓度均为Se 50 mg/L,硒肥溶液喷施量为1.8 L/m2。当茶树蓬面1芽2叶占比达30%左右时,每个小区随机选取30 cm×30 cm茶蓬,调查蓬面新梢总数、1芽2叶数量、1芽2叶长度和百芽重。同时,取1芽2叶新梢样品,测定茶多酚、儿茶素、咖啡碱、游离氨基酸、花青素以及硒含量。【结果】与A0B1处理相比,A3B1处理茶树萌展值显著降低了0.14,但对茶树蓬面新梢总数无明显影响;A2B1处理茶树1芽2叶新梢长度和百芽重分别显著降低了1.04 cm和1.94 g。A1B2和A3B2处理茶树蓬面新梢总数分别显著降低了17.66和22.33,但不影响其萌展值;A1B2显...     

叶面喷硒对不同作物籽粒硒含量及产量的影响

分析了黑龙江省主栽作物(水稻、大豆、玉米和小麦)叶面喷硒的效果。结果表明:原始籽粒含硒量以大豆最高,玉米最低,顺序为大豆小麦水稻玉米;而施入等量的硒后,4种作物籽粒硒含量都有明显的提升,提升幅度与喷硒量呈正相关,其中以小麦和水稻增加最高,大豆次之,玉米最少,且硒含量均在安全补硒值的范围之内。叶面喷硒后作物增产效果不明显。确定了叶面喷硒的浓度范围为11.25~22.50 g·hm~(-2),即可使水稻、大豆、玉米和小麦籽粒中硒含量满足低硒区居民补硒的需要;施硒时期综合比较,水稻的最佳喷硒时期是在扬花后期,玉米的最佳喷硒时期是在抽雄期,大豆是在初花期,小麦是在孕穗期。腐植酸硒降低了高浓度硒对作物的毒害作用,在生产实际中更具有安全性。     

水稻一次性施肥技术及其应用效果评价

对水稻一次性施肥技术的技术原理及其可行性进行了论述。以自行研制的水稻缓释肥为载体的水稻一次性施肥技术在广东省大范围大面积开展应用示范,结果表明:移栽前一次基施水稻缓释肥450~600 kg/hm2,完全可满足水稻整个本田生育期对养分的需求。与常规施肥比较,水稻一次性施肥技术平均可增加稻谷497 kg/hm2,增产率7.76%,获显著增产的概率达69.4%,平产概率占28.6%;一次性施肥技术还可减少养分施用量33.5 kg/hm2,节省肥料施用量10.5%。证明该技术在广东省稻作区应用的增产节肥效果稳定,技术可行。     

湖北省水稻施肥效果及肥料利用效率现状研究

2006至2008年在湖北省17个县(市、区)分别布置早、中、晚稻试验54个、136个和61个,研究在当前生产条件下平衡施用氮、磷、钾肥对水稻产量及经济效益的影响,明确当前水稻生产中的肥料贡献率及农学利用率现状,为湖北省水稻高效生产提供理论依据。结果显示,与不施肥对照相比,早、中、晚稻平衡施用氮、磷、钾肥分别平均增产稻谷2153、2445和1908 kg/hm2,增产率分别为57.4%、44.0%和42.3%;分别增收1691、2413和1413 Yuan/hm2。肥料对早、中、晚稻产量的贡献率分别为33.3%、28.6%和27.8%;肥料农学利用率分别为7.2、7.6和6.1 kg/kg。表明目前湖北省水稻平衡施用氮、磷、钾肥的增产、增收效果显著,平衡施肥是提高稻谷产量的关键技术。     

长期肥料试验对土壤和水稻微量元素及重金属含量的影响

长期肥料试验会影响土壤中微量元素和重金属状况以及作物对微量元素和重金属的吸收。本文研究了长期的不同施肥处理对土壤、糙米中微量元素Cu、Zn、Fe、Mn和重金属Pb、Cd含量的影响,结果表明:经17a连续施用猪粪及秸秆还田显著增加了土壤Cu、Zn和Cd全量,而土壤Fe、Mn和Pb全量在不同施肥处理间没有显著差异;施肥增加了土壤有效态Cu、Zn和Fe含量,其中施用猪粪及秸秆还田的3个处理显著增加了土壤有效态Cu、Zn和Cd含量,而土壤有效态Pb含量在不同施肥处理间没有显著差异。不同处理糙米Cu、Zn、Fe、Mn和Pb含量变化较小或没有显著性差异,而在3个施猪粪和秸秆还田处理中,糙米Cd含量均超过国家食品卫生标准(>0.2 mg kg-1)。水稻地上部吸收积累Cu、Zn、Fe、Mn、Pb和Cd总量与其地上部生物量呈正相关,土壤Cu、Zn、Cd有效态与全量含量呈极显著相关关系,而糙米中的镉含量与土壤镉含量有较好的相关关系。长期施用畜粪导致土壤Cd污染问题应引起高度重视。     

Foliar application of selenite to barley plants low in selenium

Abstract

Experiments with foliar application of selenite to barley crops were carried out on a number of Danish farms during the years 1975 to 1979. The plants were treated at the growth stage of Feekes 4–6 with 2.5, 5 and 10 g Se/ha, and analysed for selenium at harvest. The conclusion from the results is that spraying of 3–5 g Se with a detergent at about Feekes 5 is a safe, cheap, and effective way of preventing an outbreak of selenium deficiency in livestock mainly feeding on cereals.     

L-半胱氨酸对水稻根系吸收亚硒酸盐的影响

硒是人和动物体内必需的微量营养元素。许多地方性疾病如克山病、大骨节病等均与环境中硒水平低有关[1]。硒对人和动物健康从有益到有害的范围很窄[2-4],摄入过量硒会引起人畜中毒[5-6]。由于人体内的硒主要通过植物性食物获得[7-8],因此探讨根外环境中影响植物吸收硒的因素,进一步通过施肥措施调节植物对硒的吸收以及调控植物性产品可食部分硒含量,确保食用安全和人体健康是非常必要的。在土壤中,硒主要以元素硒(Se0)、硒化物(Se2-)、亚硒酸盐(SeO32-)、硒酸盐(SeO42-)和有机态硒[(CH3)Se]五种形态存在。其中可以被植物根系直接吸收利用的无机硒主要有硒酸盐和亚硒酸盐[8]。研究表     

氢化物原子荧光光谱法测定水溶肥料中的硒

文章介绍了原子荧光光谱法测定水溶肥料中硒含量的方法。该方法具有操作简单、快速、基体干扰少、灵敏度高等优点。该方法检出限为0.24 μg/L,线性范围0 μg/L～300 μg/L,加标回收率96.5%～103.0%。     

Effects of selenate addition on selenium accumulation and plant growth of two Prunus rootstock genotypes

A pot experiment was conducted with two Prunus genotypes (GF 677 and Mr.S.2/5, commercial rootstocks for peach), which are widely used in Italy and other European countries. Selenium (Se) was added as sodium selenate to 3‐month‐old micropropagated plants at a rate of 0 (control), 1.0, 2.5, and 5.0 mg Se (kg soil)^–1. Plant growth, gas exchange, and Se accumulation were studied. Selenium added at a rate of 2.5 and 5.0 mg Se kg^–1 appeared to be highly toxic for the two young peach rootstocks. Thirty‐three days after the treatment, the plants showed a high mortality rate. The fast growing rootstock, GF 677, appeared to be more sensitive to Se toxicity, the mortality rate reaching 52%. The higher the Se concentration in the soil, the higher it also was in the plant. In general, both genotypes were able to take up Se and to translocate high amounts from root to leaf. After selenate addition to the soil, both GF 677 and Mr.S.2/5 plants showed reduced plant growth with the highest Se treatments. Furthermore, Se induced a partial stomatal closure, as evidenced by the values of stomatal conductance, resulting in a reduction in net assimilation, and thus a decrease in dry‐matter production. Selenate applied at a low rate (1 mg Se kg^–1) stimulated plant growth in GF 677. One year after the Se treatment, a remobilization of Se from the storage organs to the young shoots was detected. This study demonstrates genotypic variation in Se uptake and accumulation in peach rootstocks.     

Modeling a long-term effect of rice straw incorporation on SOC content and grain yield in rice field

ABSTRACT

The long-term effects of rice straw incorporation on soil organic carbon (SOC) content and rice yield were evaluated from rice cultivation with different treatments: no rice straw (control), rice straw (RS), and rice straw compost (RSC) as a main-plots; five levels of nitrogen (N) fertilizer application: 0, 100, 150, 200, and 250 of N (kg ha^?1) as a sub-plots. The denitrification and decomposition (DNDC) model was employed to simulate changes in SOC content and rice grain yield over 35 years. Additionally, scenario analysis on continuous or discontinuous RS incorporation in rice fields was conducted using the DNDC model. The long-term results indicated that RS and RSC treatments played a crucial role in increasing grain yields by 9% and 11% due to the increased SOC contents compared to control treatment. The validated DNDC model on SOC contents and yields showed a good agreement between the observed and simulated values based on the normalized root mean square errors. The model predicted a rapid decline of SOC contents without RS incorporation. Results suggested that incorporating rice straw or amending manure to paddy soils is a preferred practice for maintaining SOC contents.     

硒对水稻光合作用及抗氧化作用的影响

硒是植物非必需营养元素,但是适量的硒对植物生长有着促进作用。通过研究硒对水稻光合作用及抗氧化作用的影响为硒对水稻生长的促进作用提供依据。采用盆栽试验,研究不同施硒浓度(0~5 mg/kg)对水稻产量、硒含量、叶绿素含量、光合参数、抗氧化酶活性及细胞膜透性的影响。结果表明,施硒显著提高了水稻产量,在1.0和5.0 mg/kg施硒水平较对照(不施硒)分别增产20.8%和28.8%。施硒提高了水稻谷壳、大米、秸秆及根中硒的含量。施硒对水稻叶绿素a和叶绿素b含量影响不大,但在5.0 mg/kg施硒水平上显著增加了水稻类胡萝卜素含量。施硒显著增加了叶片胞间二氧化碳浓度、蒸腾速率和光合速率,最高增幅分别为28.4%、26.1%及25.0%。施硒显著降低了水稻叶片离子渗漏量及相对电导膜透性。施硒显著增加了超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性,最高增幅分别为101.2%、23.4%和64.3%。试验结果表明,硒能增强水稻的光合作用及抗氧化作用,从而达到了促进水稻生长的效果。     

基于临界氮浓度的加工番茄优化施肥效应研究

为研究基于临界氮浓度模型的施肥方案下加工番茄对氮素的吸收利用、氮营养指数和氮素亏缺值的影响,选用新疆大面积种植的加工番茄品种“里格尔 87-5”为研究对象,设置不施氮(N0)、施氮 200 kg·hm -2(N1)、施氮 300 kg·hm -2(N2)和施氮 400 kg·hm -2(N3)4个处理进行田间试验。结果表明,在拉秧期施氮 300 kg·hm-2处理的干物质积累量最高,施氮 400 kg·hm -2处理不会促进干物质的增加;氮浓度在各取样日随施氮量的增加而增加,且随着生育期的推进呈下降趋势。施氮 300 kg·hm -2处理的氮素吸收量在拉秧期最高,两年分别为 289.49和 263.59 kg·hm -2;各处理随着生育期的推进,氮素积累量往果实中转移,且施氮 300 kg·hm -2处理的氮素转移量最大。在加工番茄苗期阶段施氮 300 kg·hm -2和施氮 400 kg·hm -2的处理均会使加工番茄田间氮素过量,施氮 200 kg·hm -2处理的氮营养指数最接近 1,且氮亏缺量在各处理间无明显差异;在开花期后施氮 300 kg·hm -2处理的氮营养指数最接近 1,且氮亏缺量最接近 0。新疆滴灌加工番茄的最佳氮肥施用总量为 278 kg·hm-2,苗期至开花期、开花至坐果期、坐果至红熟期和红熟至拉秧期的施氮比例分别为 16%、26%、49%和9%,此施肥方案为氮素的充分利用和加工番茄的持续高产提供了技术支撑。