不同施肥方式烤烟叶片矿质元素含量变化及其与干物质积累的关系

为了研究不同施肥方式下烤烟叶片中N、P、K、Ca、Mg、B、Cu、Fe、Mn、Zn 10种矿质元素的含量变化及其与干物质积累间的相关性,于2015~2016年连续2年以南阳市烤烟品种云烟87为试材,设置3种不同的施肥方式(T1:沟灌常规施肥,T2:水肥一体化,T3:水肥一体化+黄腐酸钾)在田间进行对比试验。结果显示,烟叶中10种矿质元素含量高低表现为NCaKPMgMnFeZnBCu;水肥一体化处理矿质元素含量显著高于常规处理。不同施肥方式下叶片内矿质元素含量的变化趋势表现为N、Ca、Mn、Zn,呈先上升后下降的趋势,60~80 d达到峰值;K、Cu、Fe含量在生育期内呈逐渐下降趋势,Mg元素含量表现为先下降后上升;B、P含量在生育期内变化差异不明显;叶片内N、P、K含量之间均呈极显著正相关,表明这3种元素彼此间存在增效作用;Fe与N、Ca、Mg、Mn 4种元素含量变化呈极显著负相关,表明Fe与这4种元素间均存在拮抗作用。元素含量与干物质积累间的相关性分析表明,N、P、K在40~70 d内均与干物质积累呈显著正相关。因此与常规处理相比,水肥一体化能提高烟株对矿质元素的吸收和积累,促进后期落黄成熟,提高干物质积累量。     

荔枝叶片养分含量动态及不同比例钾、氮肥施用效应

【目的】探索荔枝叶片养分含量的周年变化规律及钾、氮肥不同施用比例对荔枝产量及其种植效益的影响,为荔枝生产中的施肥管理、营养调控与增产增效提供理论依据和实践指导。【方法】在大田栽培条件下,以1995年嫁接苗种植的国内主栽品种妃子笑为试材,设置钾、氮肥不同施用比例（K2O/N分别为0.6、0.8、1.0、1.2和1.4）5个处理,随机区组排列,于2009~2012年3个生长季在广东省惠州市荔枝主产区进行试验。在荔枝不同生育期定期采集荔枝叶片测定矿质元素含量,荔枝成熟时于田间按小区实收称重测产。【结果】荔枝叶片不同生育期的养分含量存在明显差异;在整个生育期,叶片养分含量的大小均表现为N﹥K﹥Ca﹥Mg﹥P﹥S﹥B﹥Zn﹥Mo;叶片K与Ca、Mg含量有极显著的负相关关系,K与Zn含量呈显著负相关,而Ca、Mg、Zn含量两两间呈显著正相关;叶片N与S、B含量呈显著负相关,而S与B呈极显著正相关;叶片P与Ca、Si含量呈显著负相关,而Ca与Si呈显著正相关。等氮基础上随着K2O/N比的提高,荔枝产量和种植效益均出现先升高后降低的规律;以K2O/N比例为1.0~1.2时荔枝产量最高、效益最好。【结论】在我国荔枝主产区以保持钾、氮肥养分施用比例（K2O∶N）为1.0~1.2为宜。     

叶类蔬菜硝酸盐与矿质元素含量及其相关性研究

对重庆市 2 3种叶类蔬菜NO-3 和部分矿质元素含量及其相关性研究结果表明 ,不同蔬菜、同一蔬菜不同品种NO-3 和矿质元素含量差异很大 ,除莴笋、西生菜和瓢儿白 (卷心 )鲜菜食用安全外 ,其他均有不同程度污染 ,且以芹菜食用安全性最差。不同叶类菜矿质元素间多数相关性很好 ,尤以N、P、K(除个别元素外 )与其他矿质元素呈显著或极显著正相关 ;叶类菜鲜样中NO-3 含量与K、Na、Ca和Fe呈显著或极显著正相关 ,叶类菜干样中NO-3 与P、S、Mn、Zn、B和Mo呈负相关 ,且与B、P达显著负相关     

不同海拔高度植烟土壤有效钙镁的分布状况——以云南曲靖烟区为例

为探明不同海拔高度植烟土壤有效Ca、Mg的差异和分布状况,采集了2552个曲靖烟区1300～2300m海拔高度土壤样品,利用数理统计和地统计学方法对其有效Ca、Mg进行了研究。结果表明:曲靖烟区土壤有效Ca、Mg含量平均为2640.86mg/kg、314.26mg/kg。中海拔地区土壤有效Ca含量最高,低与较低海拔地区土壤有效Ca含量适宜,高与较高海拔地区土壤有效Ca含量处于低水平范围内。随着海拔高度的增加,土壤有效Mg含量递减。低与较低海拔地区土壤有效Mg含量过高,其他地区适宜。土壤有效Ca、Mg含量与海拔高度呈极显著负相关。较低和低海拔地区土壤Ca/Mg比值显著低于其他地区,中海拔地区Ca/Mg比值最大。土壤有效Ca与有效P呈极显著负相关,与其他土壤养分指标呈极显著正相关,有效Mg与碱解N、有效P呈显著负相关,与其他土壤养分呈极显著正相关。曲靖烟区土壤有效Ca含量从东往西逐渐下降,有效Mg则是南北高,中间低,Ca/Mg比值在东部地区较大,而南北部地区和西部地区较小。     

不同早实核桃品种叶片矿质元素含量变化及其与产量的关系

试验于2010~2011年连续2年以济源市4个早实核桃品种香玲、鲁光、中林1号、薄丰为试材进行了对比试验,研究了不同采样时期叶片中N、 P、 K、 Ca、 Mg、 Fe、 Cu、 Mn、 Zn 9种矿质营养元素的含量变化及其与产量的关系。结果表明,早实核桃叶片中9种元素的含量在年周期内呈规律性变化,含量高低依次为 Ca＞N＞Mg＞P＞K,Fe＞Mn＞Zn＞Cu。不同品种各元素的含量变幅最大为127.69~169.53 mg/kg（Mn）,最小为2.1~92.26 g/kg（K）。不同早实核桃品种叶片内矿质元素含量的年变化趋势表现为N、 P、 K总体上呈下降趋势,最高含量为展叶期（4月20日）分别为36.79、 5.54、 2.93 g/kg,最低在落叶前期（9月28日）,分别为17.45、 2.66、 1.86 g/kg;Ca、 Mg、 Fe、 Mn 4元素含量的变化总体上表现为前期低后期高;Cu、Zn含量的变化有差异但差异不明显。总的来看, 5~7月份,即新梢速长期（5月20日）至硬核期（7月20日）是核桃树养分稳定的时期, 叶片中N、 P、 K含量之间呈极显著的正相关, N、 P与Ca、 Mg、 Mn、 Cu间呈极显著的负相关,可以认为N、 P、 K之间存在增效作用,Ca、 Mg、 Mn、 Cu 对N、 P 和 K 均存在一定的拮抗作用。元素含量与产量的相关分析表明,N、 P、 K在新梢速长期均与产量达（极）显著正相关,相关系数分别为0.819、 0.843和0.895。因此, 利用叶片进行营养诊断最佳,采样时间以新梢速长期（5月20日前后）为宜。     

我国大豆主要矿质元素含量及其地区差异

地我国不同地区９０个大样本９种元素含量分析结果表明偿同地区大豆元素含量有差异,某些元素含量变化具有一定的地理分布规律,黄淮海地区大豆Ｃａ含量高,Ｚｎ和Ｐ含量由北向南递增,Ｂ含量北方高于南方。９种元素含量依次为Ｋ〉Ｐ〉Ｃａ〉Ｍｇ〉Ｆｅ〉Ｚｎ〉Ｍｎ〉Ｂ〉Ｃｕ。大豆中Ｚｎ与Ｐ、Ｆｅ、Ｍｇ含量呈显著或极显著正相关,与Ｋ、Ｃａ、Ｂ呈极显著负相关;Ｍｇ与Ｍｎ呈显著正相关;Ｂ与Ｃａ呈极显著正相关,与Ｚｎ、Ｐ呈极     

马铃薯栽培品种和地方品种矿质元素含量差异分析

为明确地方品种在马铃薯微营养育种中的利用价值,本研究以46份马铃薯为试验材料,对比分析栽培品种和地方品种之间9种矿质元素(K、P、Na、Mg、Ca、Fe、Mn、Zn、Cu)含量的差异。结果表明,马铃薯各矿质元素的平均含量由高到低依次为KPMgCaFeNaZnMnCu,且各元素在栽培品种和地方品种内均存在较广的遗传多样性。栽培品种的K、P、Zn平均含量显著高于地方品种,而Na含量显著低于地方品种。相关性分析结果表明,栽培品种和地方品种马铃薯中K含量与P含量均呈极显著正相关(P0.01),Zn含量、Mg含量与Mn含量呈显著正相关(P0.05)。聚类分析结果显示,试验用马铃薯可分为3类,每一类中既有栽培品种,又有地方品种,说明地方品种在马铃薯矿质元素微营养育种改良中的利用价值不大。本研究结果为地方品种在矿质元素微营养育种中的利用价值方面提供了一定的参考。     

烤烟中微量营养元素含量与物理特性的关系探讨

通过分析我国2010—2014年C3F等级的初烤烟叶中6种中微量营养元素(Mn,Fe,Cu,Zn,Ca和Mg)含量与烟叶厚度、叶面密度、平衡含水率、拉力、填充值和含梗率6项物理特性指标以及物理特性总分间相关性,得到如下主要结论:(1)烟叶厚度和叶面密度与Mn和Zn含量呈极显著负相关关系,与Ca和Mg含量呈极显著正相关关系。(2)Zn和Mg对烟叶的物理特性指标影响最大,其中Zn主要影响烟叶厚度、叶面密度、拉力等指标;Mg主要影响烟叶厚度、叶面密度等指标。(3)Ca含量越高,烟叶越厚,但填充性能越差,过高的Ca含量会降低烟叶的吸湿性能。     

当归药材与产地土壤中无机元素的相关分析研究

采用ICP-MS和AAS测定了95批当归药材及其产地土壤中8种重金属元素和7种其他无机元素含量,研究药材与产地土壤中无机元素的相关性。结果表明,当归药材中的特征性无机元素是Fe、Mn、Mg、As、Cr及Ni,土壤中的特征性无机元素是Zn、Mn、Pb、Cr及Ni;当归药材中,无机元素Mn与Zn、Cr、Fe、Cu,Ni与Fe、Cd、Sb、Zn,As与Sb、Pb、Cr、Mn,Cu与Mg、Pb、Zn,Cr与Fe、Pb,Mg与Sb、Zn,以及Ca与Na呈显著正相关,而K与Na、Pb、Cd呈显著负相关;当归对土壤中的Na有富集作用;无机元素Sb、Ca和Na在当归药材与土壤中呈显著正相关。研究发现,中药当归含有丰富的有益无机元素,有害重金属元素含量极低,符合相关标准,在国际贸易及GAP种植方面具有明显的优势和广阔的发展前景。     

不同钾氮配比对荔枝果实矿质元素含量及其耐贮性的影响

【目的】在广东省惠州市荔枝主产区,于2009 2012年连续3年研究不同钾氮养分比例对荔枝果实矿质元素含量的影响及其与耐贮性的关系,以期为荔枝高产优质高效栽培与耐贮增值的科学施肥技术提供理论依据。【方法】在大田栽培条件下,以1995年嫁接苗种植的国内主栽品种妃子笑为试材,设钾氮不同施用比例(K2O/N分别为0.6、0.8、1.0、1.2和1.4)5个处理,分别用K0.6N、K0.8N、K1.0N、K1.2N、K1.4N表示。在荔枝收获期测定果实矿质元素含量,并进行室温(25±1°C)自然贮藏试验,每2d采样测定相关贮藏指标。【结果】1)随着K2O/N比的提高,荔枝外果皮钾(K)、硼(B)含量呈下降趋势,内果皮K含量呈先下降后增加,果肉K、内外果皮和果肉钙(Ca)、内果皮B含量均呈现先增加后下降,果核Ca含量呈现逐渐增加的趋势。2)随着K2O/N比的提高,内外果皮K/Ca、Mg/Ca、(Mg+K)/Ca、K/B比均呈先下降后增加,外果皮Ca/B比呈增加的趋势。3)内果皮K含量与果实好果率呈极显著负相关,外果皮Ca、内果皮B含量与果实好果率呈显著或极显著正相关。内、外果皮K含量与果皮细胞膜透性呈显著正相关,外果皮Ca含量与果皮细胞膜透性呈显著负相关。内、外果皮K含量与多酚氧化酶(PPO)、过氧化物酶(POD)活性呈显著正相关,而内、外果皮Ca含量则与两种酶活性呈显著负相关。4)内、外果皮K/Ca、Mg/Ca、(Mg+K)/Ca和K/B比与果实好果率呈显著或极显著负相关,与果皮细胞膜透性、PPO和POD活性均呈显著或极显著正相关,而Ca/B比则完全相反。【结论】荔枝生产中合理调控钾、氮养分施用比例(K2O/N),不仅可以提高内、外果皮的Ca/B比值,还有利于降低内、外果皮K/Ca、Mg/Ca、(Mg+K)/Ca和K/B的比值,对提高果实耐贮性具有重要作用。本试验条件和施肥方法下,K2O/N的施用比例以1.2∶1时能最大限度地满足优良耐贮性能适宜的养分含量及比例。     

Accumulation of copper in soils and leaves of tomato plants in greenhouses in Turkey

Copper (Cu)‐containing fertilizers, fungicides, and bactericides has been used extensively in the greenhouses in the Antalya province in recent decades with the use of such materials tending to increase year by year. The level of DTPA‐extractable Cu was determined in 210 soils (0–20 and 20–40 cm depth) and 105 leaf samples obtained from 105 tomato greenhouses. The DTPA‐extractable Cu contents of the soils taken from the 0–20 depth ranged between 0.76 and 88.03 mg kg^‐1 (mean 7.79 mg kg^‐1). The percentage of soils containing DTPA‐extractable Cu greater than the critical toxicity level (20 mg kg^‐1) was 8.1. The Cu content of tomato leaf samples ranged between 2.4 and 1,490 mg kg^‐1 (mean 166.5 mg kg^‐1). The Cu concentration in leaf samples was very high due to the intensive use of foliar applied Cu‐containing chemicals. As a consequence, 24.8% of the leaf tomato samples analyzed contained over 200 mg Cu kg^‐1, the maximum accepted tolerance level. Therefore, it may be necessary to reduce the use of Cu‐containing pesticides and fertilizers, or at least reduce the amount of Cu‐containing fertilizers being used in those greenhouses where Cu‐containing pesticides have been or are being used.     

Role of selenium in mitigation of cadmium toxicity in pepper grown in hydroponic condition

Selenium (Se) is an essential element for humans but is not considered as essential for plants. However, its beneficial role in improving plant growth and stress tolerances is well established. In order to study the role of Se in cadmium (Cd) toxicity in pepper (Capsicum frutescens cv. Suryankhi Cluster), this experiment was carried out in greenhouse conditions. Treatments comprised Cd [0, 0.25, and 0.5 mM cadmium chloride (CdCl₂)] and Se [0, 3, and 7 µM sodium selenite (Na₂SeO₃)] with three replications. The result showed that Cd decreased chlorophyll a, chlorophyll b, and carotenoids, whereas Se supplementation diminished Cd toxicity on photosynthetic pigment. Selenium at 7 µM significantly increased the leaf area in the plants grown at 0.25 mM Cd. The application of Se at 3 µM with 0.25 mM Cd and Se at 3 µM and Se at 7 µM with 0.5 mM Cd increased the activity of catalase (CAT). Selenium at 7 µM decreased the proline content of pepper leaves exposed to Cd at 0.5 mM (30%). Selenium significantly enhanced the antioxidant activity of leaves, which was diminished by Cd toxicity. In general, Se has a beneficial effect on plant growth and is an antioxidant enzyme of pepper cv. Suryankhi Cluster under Cd stress and non-stress conditions.     

红壤区不同肥力水稻土根际硝化作用特征

通过根际培养箱(三室)——速冻切片技术研究了红壤地区高、低两种肥力下水稻苗期根表、根际和土体土壤矿质态氮含量和硝化强度,以及水稻生长、氮素积累的差异。结果表明,肥力水平对水稻根表和根际土壤铵态氮(NH4+-N)含量无显著影响,但高肥力显著提高土体土壤NH4+-N含量,以及根表、根际和土体土壤硝态氮(NO3--N)含量及硝化强度。两种肥力水稻土硝化强度最大值均出现在距根表2 mm处,分别为0.20和0.31μmol kg-1 h-1。土体土壤硝化强度随距根表距离增加而降低,低肥力土壤在距根表10～40mm处时硝化强度接近本底值,而高肥力土壤在距根表20～40 mm处时接近本底值。与不种水稻的CK相比,种植水稻显著提高根际土壤硝化强度。高肥力能显著改善水稻生长,增加植株氮素积累量,尤其显著促进根系生长及通气组织发育。由于红壤稻田肥力水平的差异造成水稻根际硝化强度以及水稻吸收NO3-的差异,导致高肥条件下水稻显示出更强的生长势和氮素吸收利用能力。因此,合理提高红壤稻田肥力水平对改善红壤区水稻根际土壤硝化作用及水稻氮素营养具有重要意义。     

自由基在鸡肾病发生中的作用研究

肾病即急性肾小管坏死.鸡肾病在养鸡生产中极为常见,尤其近年来,鸡肾病的发生日益增多,由于其发生机制不清楚,临床治疗鸡肾病的依据不足,致使治疗效果不佳,为此,提出本研究以探讨鸡肾病的发生机制,为本病防治提供理论依据.     

Occurrence of Sexual Hormones in Sediments of Mangrove in Brazil

The presence of sexual hormones (female estrogens) was assessed in sediments of a mangrove located in the urban region of southern Brazil. The estrogens are involved in human sexual reproduction. They act as the chemical messengers, and they are classified as natural and synthetic. The estrogens inputs in the environment are from treated and untreated sewage. The presence of estrogens in sewage is excretion from the female due to natural production and use of contraceptives (synthetic estrogens). With the indiscriminate release of sewage into the environment, estrogens can be found in rivers, lakes, and even in oceans. In this work, the presence of estrone (E1), 17-??-estradiol (E2), and 17-??-ethynilestradiol (EE2) in eight sedimentary stations in Itacorubi mangrove located on Santa Catarina Island, south Brazil, was investigated. Historically, the Itacorubi mangrove has been impacted by anthropogenic activities because the mangrove is inserted in the urban area of the Florianopolis. The estrogen EE2, used as contraceptive, had the highest concentration in mangrove sediment, 129.75?±?3.89 ng/g. E2 was also found, with its concentration ranging from 0.90?±?0.03 to 39.77?±?1.19 ng/g. Following the mechanism, under aerobic or anaerobic conditions, E2 will first be oxidized to E1, which is further oxidized to unknown metabolites and finally to CO₂ and water (mineralized). EE2 is oxidized to unknown metabolites and also finally mineralized. Theoretically, under anaerobic conditions, EE2 can be reduced to E1 even in environments such as mangrove which is essentially anaerobic.     

Meta-analysis in the Selection of Groups in Varieties of Citrus

Brazil is the largest producer of oranges (Citrus sinensis) in the world. The nutrient management of tree orchards is designed from experiments with a limited number of varieties. This knowledge is transferred to other varieties by diagnosing tissue nutrient composition and tree demand. Compositional data analysis has been first applied to tissue analysis of agricultural crops using centered log ratios with compositional nutrient diagnosis (CND-clr). The isometric log ratio (ilr) transformation is a new approach based on binary nutrient ratios and the principle of orthogonality (CND-ilr). We analyzed eleven nutrients: nitrogen (N), sulfur (S), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), boron (B), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) in leaf tissue samples across 108 commercial plots (thirty-one grow Valencia, twenty-two Hamlim, twenty Pera, and thirty-five Natal). Nutrients were partitioned between macro- and micronutrients as well as anionic and cationic species. The effect size of varieties over Valencia was quantified by the mean and standard deviation of ilr values across ilr coordinates. Specific varietal nutrient profiles and ilr norms were defined. The nutrient profile of orange varieties could be classified into homogeneous groups to take advantage of fertilizer trials conducted on varieties of the same group. The Aitchison distance and a perturbation vector could be instrumental for diagnostic purposes and nutrient management.     

Effect of iron-quercetin complex on reduction of nitrite in in vitro and in vivo systems

This study investigated whether reducing agents such as quercetin and iron(II) facilitate formation of nitric oxide (NO) gas from orally ingested nitrite in an vivo study. When 3 mg/kg Na (15)NO2 was orally administered to rats with or without iron(II) or quercetin, Hb (15)NO, which is indicative of systemic (15)NO, was detected in the blood, with the maximum blood concentration of Hb (15)NO at 15 min after nitrite or nitrite plus quercetin treatment, whereas after administration of nitrite plus iron(II) or nitrite plus iron(II) and quercetin, the time was shortened to 10 min. Interestingly, iron(II), quercetin, or iron(II) plus quercetin did not affect the total amount of Hb (15)NO generated from orally administered Na (15)NO2. However, the systemic nitrite concentration was significantly decreased in the presence of iron(II) or iron(II) plus quercetin. These results may indicate that iron(II) is critical to the generation of NO gas from nitrite, whereas quercetin contributed little under the in vivo experimental conditions.     

旱地果园水肥管理模式研究进展

分析了旱地果园水肥管理模式的研究进展和存在问题,指出水肥胁迫尤其是水钾已成为旱区果树高产稳产优质化的主要限制因子。在系统探讨旱地果园水分管理、养分管理、综合管理以及果树叶营养综合诊断施肥标准的基础上,提出了旱地果园的高效水肥管理模式。     

Role of aldehyde oxidase in the hepatic in vitro metabolism of 3-methylindole in pigs

The metabolism of 3-hydroxy-3-methylindolenine (HMI), a recently discovered metabolite of 3-methylindole (3MI, skatole) produced by porcine liver microsomes, was investigated in vitro using porcine liver cytosol. HMI was rapidly metabolized to a single product, 3-hydroxy-3-methyloxindole (HMOI), by porcine cytosol. By the use of the selective inhibitors menadione and quinacrine, it was shown that the enzyme responsible for the oxidation of HMI into HMOI was aldehyde oxidase (AO; aldehyde:oxygen oxidoreductase, EC 1.2.3.1). The activity of AO in the conversion of HMI to HMOI was measured in a population of pigs (n = 30) with a wide range of 3MI levels in back fat (0.07-0.30 mg/kg). AO activity was found to be negatively correlated (r = -0.70; P < 0.001) with the level of 3MI in fat. The results of the present study suggest that AO plays an important role in the metabolism of 3MI in the pig and that its catalytic activity is related to an adequate 3MI clearance.     

北京市郊典型农田施肥研究与分析

通过问卷调查形式,对京郊粮田、菜田和果园3种农田施肥现状进行研究.结果表明,菜田和果园化肥施用量较高,氮、磷、钾肥均显著高于粮田.菜田和果园氮肥用量分别为1741.0和1172.8 kg/hm2,分别是粮田氮肥用量的4.5和3.0倍;磷肥用量分别为1375.1和996.4 kg/hm2,分别是粮田磷肥用量的15.5倍和11.2倍;钾肥用量分别为791.3和602.4 kg/hm2,分别是粮田钾肥用量的21.1和16.1倍.另外,3种利用方式的农田氮、磷和钾肥施用比例不同,粮田为75.4%、17.3%和7.3%;果园为42.3%、36.0%和21.7%;而菜田为44.6%、35.2%和20.3%.3种种植类型中均存在氮肥投入过量、钾肥不足的问题.