三亚市主要冬种蔬菜硝酸盐含量分析与评价

采用水杨酸-硫酸比色法，测定了三亚市5个蔬菜市场中4类17个品种110个冬种蔬菜样品的硝酸盐含量。结果表明：硝酸盐含量由高至低依次为：叶菜类＞豆类＞茄果类＞瓜果类，4类蔬菜含量均低于无公害蔬菜硝酸盐含量限值。17个品种蔬菜的硝酸盐含量分布在15～1 520 mg/kg，均受到不同程度的污染，其中叶菜类污染较为严重。     

广西梧州六堡茶产区土壤硒含量及其与茶叶中硒的相关性分析

采集广西梧州市六堡茶产区茶园土壤样品和对应茶鲜叶样品进行检测与分析,探讨茶园土壤硒含量及其与茶叶中硒含量的相关性.结果表明,各试验茶园土壤pH平均值为4.0～6.5;土壤全硒平均含量为2.28 mg/kg,远高于富硒茶园的土壤标准;茶园土壤剖面中各土层之间全硒含量在1.85～1.95 mg/kg,土层之间没有显著差异;各茶园茶叶中全硒平均含量为0.66 mg/kg,枝条中全硒平均含量为0.58 mg/kg;茶鲜叶、茶树枝条与土壤全硒含量均呈现极显著正相关.     

海南甘蔗土壤养分状况研究

通过对海南西部儋州、昌江、白沙,北部临高、澄迈和定安,主要甘蔗产区0～20cm土层共85个样品进行分析。结果表明,海南蔗区土壤pH值平均为4.50,88.23%的样品pH值5.5;土壤有机质含量平均为15.3g/kg,38.82%的样品有机质含量小于10g/kg;62.35%的样品碱解氮含量低于60mg/kg;38.82%的样品有效磷含量小于10mg/kg;78.82%的样品速效钾含量小于50mg/kg;60.0%的样品交换性钙含量小于450mg/kg;80.0%的样品交换性镁含量小于120mg/kg;28.24%的样品有效硫含量小于12mg/kg;83.53%的样品有效硼含量低于临界值;蔗区土壤有效锌含量和有效铁含量较为丰富。     

湘东某植烟区土壤钙对烟叶镉含量的影响

在湖南省东部某植烟区大范围采集了112个土壤样品和烟叶样品,测定并分析了土壤中镉的含量、土壤交换性钙含量、烟叶镉含量及其相关性。结果表明:植烟区土壤镉的含量范围0.08~0.82 mg/kg,平均值0.37 mg/kg,其超标率为58.13%;植烟区内烟叶镉含量范围1.06~20.15 mg/kg,平均值7.29 mg/kg;土壤总钙的平均含量为10 649 mg/kg,交换性钙平均含量为1301 mg/kg。烟叶中的镉含量与土壤中的镉含量呈极显著性正相关,与土壤中的总钙含量及交换性钙含量呈负相关,伴随着土壤中钙含量的增加,烟叶镉的含量有降低趋势。     

东莞蔬菜产区蔬菜重金属污染调查评价

对东莞主要蔬菜产区的112个蔬菜样品进行重金属污染现状调查,发现这些蔬菜受到不同程度的重金属污染,但大多数只是轻度污染,并未达到危险级别.东莞蔬菜产区蔬菜重金属人均日暴露量平均值均低于ADI值,各类蔬菜的综合污染指数均小于1,表明绝大部分蔬菜可以放心食用.     

不同浓度锌对蕹菜产量和品质的影响

采用水培研究了不同浓度锌(0、0.05、0.5、1、2和4 mg/L)对蕹菜产量和品质的影响。结果表明,锌浓度为0.5 mg/L时,蕹菜生长状况最佳,产量最高,而当锌浓度大于2 mg/L时,蕹菜生长受阻,产量下降,且产生中毒现象。与对照相比,锌浓度为0.05、0.5、1、2.00和4 mg/L的各处理均不同程度地降低了蕹菜硝酸盐含量,提高了维生素C含量、蛋白质含量和可溶性糖含量。其中锌浓度为0.5 mg/L的处理对增加蕹菜产量和提高蕹菜品质效果显著,是蕹菜水培最适合的锌施肥水平。     

海南岛芒果园施肥现状调查及土壤养分状况分析

本文主要通过了解海南岛芒果园施肥现状及对应的土壤养分状况,综合分析施肥管理现状,为芒果种植科学施肥提供理论基础。研究结果表明,海南岛芒果主产区肥料投入平均水平为 N 334.01 kg/hm2、P2O5 177.10 hm2、K2O 184.21 hm2,其中 N∶P2O5∶K2O 为 1∶0.53∶0.55,芒果化肥消耗系数为 0.059 01 kg/kg,纯氮消耗系数为 0.020 7 kg/kg,施用有机肥农户比例为 76.92%,有机肥平均施用量低于 333.33 kg/hm2。海南岛芒果主产区土壤有机质含量偏低,范围为 11.16~17.22 g/kg;碱解氮含量偏高,范围为 278.86~859.10 mg/kg;速效磷含量差异较大,为 21.74~81.73 mg/kg;速效钾含量在96.56~97.19 mg/kg。综上所述,海南岛芒果园氮磷钾肥料投入比例不科学,钾肥投入量偏低,建议增施钾肥;有机肥投入严重不足,建议提高施用有机肥农户比例,增大有机肥施用量。     

海南岛芒果园施肥现状调查及土壤养分状况分析

本文主要通过了解海南岛芒果园施肥现状及对应的土壤养分状况,综合分析施肥管理现状,为芒果种植科学施肥提供理论基础。研究结果表明,海南岛芒果主产区肥料投入平均水平为 N 334.01 kg/hm2、P2O5 177.10 hm2、K2O 184.21 hm2,其中 N∶P2O5∶K2O 为 1∶0.53∶0.55,芒果化肥消耗系数为 0.059 01 kg/kg,纯氮消耗系数为 0.020 7 kg/kg,施用有机肥农户比例为 76.92%,有机肥平均施用量低于 333.33 kg/hm2。海南岛芒果主产区土壤有机质含量偏低,范围为11.16~17.22 g/kg;碱解氮含量偏高,范围为 278.86~859.10 mg/kg;速效磷含量差异较大,为21.74~81.73 mg/kg;速效钾含量在 96.56~97.19 mg/kg。综上所述,海南岛芒果园氮磷钾肥料投入比例不科学,钾肥投入量偏低,建议增施钾肥;有机肥投入严重不足,建议提高施用有机肥农户比例,增大有机肥施用量。     

硅对烟草生长的影响及诊断指标研究

通过水培试验,研究不同供硅水平(0、0.5、1.0、2.0、3.0 mmol/L,Si O2)对烟草生长的影响和烟草硅素营养诊断指标,并对福建省烟草主产区148个烟叶样品的硅素含量状况进行测定。结果表明:供硅可提高烟草根、茎、叶的硅含量,不同部位、不同叶位的硅含量表现为根叶茎、下部叶中部叶上部叶,烟草硅素营养诊断的适宜部位为现蕾期植株中部叶,硅素诊断临界值为叶片含硅0.26%。与对照相比较,供硅对团棵期烟草的生长无明显影响,但可显著提高现蕾期烟草地上部干重和总生物量,硅可提高烟草K、P、Zn的含量,降低N、Ca、Cu、Fe、B的含量。福建省烟草主产区烟叶的硅含量范围在0.04%~0.64%,平均值为0.22%,有52%样品的硅含量低于0.26%。     

安溪铁观音主产区茶园土壤环境条件与茶叶质量提升建议

茶园土壤环境条件与茶叶质量密切相关。但目前对茶园土壤环境条件的调查研究依旧不足，为了解安溪县铁观音茶园土壤环境条件，进一步促进茶叶质量提升，本研究对福建省安溪县6个铁观音主产乡镇（感德、祥华、西坪、龙涓、剑斗、桃舟）共52个茶园土壤样品进行测定，并对pH值、有机质、碱解氮、有效磷、速效钾，污染源（镉、铅、汞、砷、铬、铜）等指标进行分析。结果表明，安溪县铁观音主产区茶园土壤pH平均值为4.27，呈酸性；有机质含量丰富，平均值达到24.00g.kg-1，各乡镇土壤有机质均处于Ⅰ级水平；碱解氮平均值为85.85mg.kg-1，龙涓乡处于Ⅰ级水平，其他乡镇处于Ⅱ级水平；有效磷含量较高，平均值为44.42mg.kg-1，均处于Ⅰ级水平；速效钾含量平均值为73.22mg.kg-1，龙涓乡及西坪镇处于Ⅱ级水平，其他乡镇处于Ⅲ级水平；污染源（镉、铅、汞、砷、铬、铜）平均含量低于茶叶产地环境技术条件和有机茶产地环境条件中的相应限值。安溪县铁观音主产区茶园土壤养分水平总体较高，但土壤存在一定程度酸化，速效钾含量相对匮乏，可通过施用土壤改良剂等缓解土壤酸化，施用钾肥补充土壤速效钾含量；土壤环境质量优良，适宜...     

设施菜地夏季休闲期甜玉米经济产量及环境效益分析

在北京市门头沟、房山、大兴和通州等4个区选择15个典型设施菜地,设置田间观察对比试验,研究在北方设施菜地夏季甜玉米作为填闲作物的实际经济、环境综合效益。试验结果表明,种植甜玉米有较好经济效益,经济产量达15 168.0～20 332.8kg/hm2。在环境效益方面,种植甜玉米后可有效减少浅层土壤中的硝态氮含量,降低淋溶风险。与常规休闲(休闲期不种植作物)相比,种植甜玉米可使设施菜地0～100cm土层中的硝态氮含量平均减少290.4kg/hm2。在夏季休闲期种植甜玉米是北方设施菜地兼顾经济和环境效益的有效种植措施之一。     

乙烯利对夏玉米子粒干物质积累的影响及生理机制探究

以郑单958为试验材料,于玉米第9展叶期喷施200、400、800 mg/L乙烯利,喷施清水作对照,测定子粒发育过程中灌浆速率及可溶性糖、淀粉和激素含量,考种计产。结果表明,400 mg/L和800 mg/L乙烯利处理显著降低郑单958的单穗重和千粒重,同时降低灌浆后期生长素(IAA)、脱落酸(ABA)和赤霉素(GA3)的含量及平均灌浆速率和最大灌浆速率,降低子粒中淀粉含量;200 mg/L乙烯利处理单穗重及灌浆速率与对照差异不显著。结合产量、干物质积累和激素含量变化分析,喷施高浓度乙烯利导致子粒中激素含量变化是子粒灌浆速率下降、干物质积累速率减慢和千粒重下降。建议生产中用200 mg/L乙烯利为主要喷施浓度。     

Fate of phosphate and nitrate in waters of an intensive agricultural area in the dry zone of Sri Lanka

The chemistry of surface waters and groundwater draining agricultural catchments in the north-central and northwestern areas of Sri Lanka is described. Hydrochemical data from 296 water samples are used to evaluate water quality and to identify the processes that control nitrate and phosphate concentrations in the water. The results indicate that nutrient concentrations in the groundwaters are greater than those in the surface waters. Increased nutrient levels were observed in groundwater in a selected area in the fortnight following fertilizer application. Detailed geochemical investigations of selected groundwater samples reveal a gradual rise of nitrate–N and other solutes along the horizontal flow direction. Compared to the application rates of fertilizer in the area, the average nutrient concentrations in all waters are relatively low (1.5 mg/l nitrate and 0.5 mg/l phosphate) and stable. The results suggest that prevailing reducing conditions, iron-rich overburden soil cover and manmade canal networks control nutrient accumulation in the groundwater.     

茶园土壤铝动态及茶树铝吸收特性

本文报告了在茶园和根际土壤铝动态及茶树铝吸收特性方面的一些研究结果。1.对210个样品测定,茶园土壤交换性铝含量为2.5-988mg/kg,平均238 mg/kg。无定形和层间铝是茶园土壤铝的主要形态;植茶后茶园土壤的水溶性、交换性和有机结合态铝趋于增加。2.茶园土壤交换性铝含量随施氮量的提高而增加;供给茶树NH_4~+-N时,茶树根际土壤(距根表 1mm)的交换性铝显著增加。3.铝在一定范围(≤400 μmol/L)增加茶树侧根数量和长度。4.动力学研究表明茶树根系对铝的吸收表现为可饱和特性,初始时有一快速的吸收过程,并在约6h后转变为缓慢的吸收。     

Impact of aluminum sub-chronic toxicity on body weight and recognition memory of wistar rat

The aims of this study was to investigate the impact of aluminum nitrate administered in drinking water during 90 days (sub-chronic toxicity), on body weight gain, motor activity, brain aluminum accumulation and especially in recognition memory of wistar rats. Two groups of young female wistar rats were used. Treated rats received (80 mg L(-1)) of aluminum nitrate diluted in drinking water, while control rats received a drinking water only, for 3 months. An evolution of body weight, a motor activity, object recognition memory (NOR) and brain aluminum concentration has been evaluated. The body weight was taken weekly, whereas the memory abilities and the motor activity are measured once every fortnight alternatively, by submitting rats to the open field test and to the novel object recognizing memory test. The results have showed a significant decrease in rats' body weight (p < 0.05). Though, no significance was registered for motor activity. Nevertheless, a high significance is showed for recognition memory compared to control rats (p < 0.01), especially at the end of testing period, even the difference between control and aluminium treated rats in brain aluminum levels was not significant.     

白鹃梅可食部分营养成分分析

[目的]分析测定白鹃梅的主要营养成分。[方法]对山野菜白鹃梅的花蕾、嫩叶（带嫩茎）和花等不同可食部位的维生素C、可溶性蛋白、可溶性糖、粗纤维、粗脂肪、硝酸盐的含量进行了分析测定。【结果】白鹃梅维生素c、粗脂肪和粗纤维含量高于常见野菜香椿、荠莱和马齿苋,分别为0．77、50．00、19．03g／kg,可溶性糖含量较低,为27．27g／kg,可溶性蛋白含量适中,为30．63g／kg,其中,白鹃梅花蕾和嫩叶（带嫩茎）的营养成分略高于花。白鹃梅的花蕾、花和嫩叶（带嫩茎）中硝态氮的含量分别为0．0790、0．1086、0．1122g／kg,属1级无公害蔬菜,可放心食用[结论]白鹃梅营养成分丰富,是一种极具开发利用价值的木本观食两用植物。     

超高效液相色谱-串联质谱法同时测定蔬菜中阿维菌素和氟吡菌酰胺的残留

为建立同时测定蔬菜中阿维菌素和氟吡菌酰胺残留的超高效液相色谱-串联质谱（UPLC-MS/MS）方法,采用乙腈高速匀浆提取蔬菜样品中的阿维菌素和氟吡菌酰胺,利用无水硫酸镁和PSA吸附剂进行净化,在UPLC-MS/MS的正离子电离和多反应离子监测模式下进行测定。结果表明,阿维菌素和氟吡菌酰胺的检出限分别为1.0、0.2 μg/kg;在0.005~0.200 mg/L浓度范围内,其线性相关系数均大于0.999。阿维菌素和氟吡菌酰胺在3个试验水平（0.01、0.02和1.0 mg/kg）的添加回收率分别为83%~106%和90%~108%,相对标准偏差分别在0.5%~5.2%和1.2%~8.4%。本方法前处理过程快速简单,仪器分析灵敏度好,方法准确度高,可用于蔬菜样品中阿维菌素和氟吡菌酰胺农药残留量的检测分析。     

The influence of fertilizer nitrogen, white clover content and environmental factors on the nitrate content of perennial ryegrass and ryegrass/white clover swards

In a field experiment carried out over 3 years, the nitrate content of herbage from perennial ryegrass (Lolium perenne) swards increased exponentially with nitrogen application rate, but herbage nitrate content appeared to reach potentially dangerous concentrations only when nitrogen application rates were greater than those needed to stimulate dry-matter production. Thus, on average over all the harvests, maximum yield could be obtained with annual application rates of 400 kg N ha^–1 (six applications of 67 kg N ha^–1) for perennial ryegrass and 300 kg N ha^–1 (six applications of 50 kg N ha^–1) for perennial ryegrass/white clover (Trifolium repens) swards, whereas the mean nitrate concentrations were 3340 and 2929 mg NO₃ kg^–1 dry matter (DM) respectively. Nitrate content, however, varied considerably from harvest to harvest, reaching maxima of 9345 mg NO₃ kg^–1 DM at 400 kg N ha^–1 for perennial ryegrass and 6255 mg NO₃ kg^–1 DM at 300 kg N ha^–1 for perennial ryegrass/white clover. The nitrate content of herbage from perennial ryegrass/white clover swards was always greater than that of perennial ryegrass swards receiving the same rate of nitrogen application, even though in the herbage from the mixed sward the nitrate content of white clover was usually less than half that of the perennial ryegrass component. The physical environment did not have a clearly interpretable effect on nitrate content, although herbage harvested in May had a much lower nitrate content than that harvested at any other time of the season. It was not possible to find a single multiple regression equation relating herbage nitrate content to nitrogen application and to other environmental variables that explained more than 60% of the variance in herbage nitrate, but it is suggested that, by reducing the later-season nitrogen applications from 67 to 50 and finally to 33 kg N ha^–1 for perennial ryegrass and from 50 to 33 kg N ha^–1 for perennial ryegrass/white clover, it would be possible to achieve over 90% of the maximum yield while reducing average nitrate content to <40% of that at maximum yield, with no samples containing more than 2300 mg NO₃ kg ^–1 DM.     

海南树仔菜中镉含量测定及质量安全风险评估

用石墨炉原子吸收法测定采自海南几个市县栽培的树仔菜样品中镉含量.结果表明,测定的25个树仔菜样品镉含量均低于食品中污染物限量国家标准(GB 2762-2005)的0.2 mg·kg~(-1),其中有5个样品镉含量低于无公害蔬菜安全标准(GB18406.1-2001)0.05 mg·kg~(-1).依据国家有关标准,结合国内外大量的文献资料报告,按照危害识别、危害描述、暴露评估和风险描述四个步骤进行质量安全风险评估,评估结果为:海南树仔菜中镉的质量安全风险尚不足以造成对人体健康的危害.