山东省主产区板栗农药残留分析

为了解山东省主产区毛板栗中农药残留分布特征及其潜在的生态风险,对40个板栗产区的63份板栗抽样分析。研究结果显示:山东省主产区板栗中六六六和滴滴涕呈正态分布,其中ΣHCH0.005mg/kg和ΣDDT0.032mg/kg,所有测定值基本低于国家食品质量背景值标准,而除虫菊酯和有机磷农药均未检出,板栗中农药残留均处于国家食品质量背景值标准规定的安全水平。     

苦竹笋、叶营养成分分析

对苦竹笋、叶的营养成分进行测定,结果表明:苦竹鲜笋、竹叶粗蛋白分别为24.8 g·kg-1、170.6 g·kg-1,粗纤维分别为6.1 g·kg-1、287.4 g·kg-1,磷380.0mg·kg-1、1 350.6 mg·kg-1,铁11.0 mg·kg-1、199.85mg·kg-1,钙16.2 mg·kg-1、3 635mg·kg-1;游离氨基酸和水解氨基酸鲜笋为2.014 g·kg-1、22.28g·kg-1;苦竹叶(干重)为3.599 g·kg-1、169.26g·kg-1;苦竹笋、叶的氨基酸等营养成分含量高于毛竹的笋和叶,是开发竹子保健食品的理想原料.     

气质联用法(GC-MS)测定水果中农药残留含量研究

该文采用气质联用法测定水果中有机磷及拟除虫菊酯类等农药残留的含量,研究不同的限用农药在水果中残留情况,从而对果类安全作初步评价。结果表明:水果中含量高的农药残留集中为拟除虫菊酯类农药,并且在苹果、橘子及枣上比较突出。选定的9种水果中,农药残留检出的多少呈以下规律:苹果枣橘子人参果桃梨、猕猴桃。检出农药的种类依次为:甲氰菊酯三氟氯氰菊酯磷胺联苯菊酯。50个水果样品中农药残留均未超标。     

核桃仁中3种菊酯类农药残留的检测方法

利用ENVI-18-PSA串联固相萃取柱对核桃仁进行预纯化,在高纯氮气(99.99%),流速1.5 m L/min,进样口温度290℃,起始柱温度100℃,以10℃/min的速度升温到300℃的条件下完成气相色谱质谱法(GC-MS)检测氟氰戊菊酯、溴氰菊酯和高氰戊菊酯,并确定其检出限分别为5.9μg/g,3.4μg/g和4.0μg/g.建立了一种检测核桃仁中溴氰菊酯、氟氰戊菊酯和高氰戊菊酯3种菊酯类农药微量残留的方法,本方法的检出限、回收率等技术指标均可以满足核桃仁农药残留分析的需要。     

余杭早竹笋产业发展问题及对策措施

早竹是一种优良笋用竹,由于传统的栽培模式过分地依赖于农药化肥等的投入,导致竹园病虫害发生频繁,土壤理化性质恶化,有害物残留增长等问题,影响了早竹笋品质和卫生安全.通过对早竹笋生产经营中存在的主要问题的分析,提出了全面推行无公害早竹笋新型栽培模式、建立健全监测检验体系、强化品牌经营等对策措施,以做优做强余杭早竹笋产业.     

罗汉果中有机氯残留量的分析及限量标准的制定

为给科学制定产品质量标准提供依据,采用随机取样的方法,对我国广西壮族自治区罗汉果主产区永福县龙江乡、临桂县茶洞乡、龙胜县三门乡和融安县雅瑶乡的罗汉果上农药残留情况进行了调查,并采用日本岛津GC-14B气相色谱仪对其残留农药六六六(α-BHC、β-BHC、γ-BHC、δ-BHC)、DDT(P.P-DDT、O.P-DDT、P.P-DDE、P.P-DDD)、艾氏剂(Aldrin)的含量进行了测定与分析,并参照我国中药材有机氯六六六、DDT、艾氏剂的残留量的相关标准,制定了我国罗汉果有机氯农药残留的限量标准。     

岷江上游干旱河谷油松刺槐混交林研究

经过连续6a对岷江上游干旱河谷油松刺槐混交林分的土壤水分、养分、理化性质及林冠结构和效益研究,结果表明:(1)混交林土壤0~40 cm平均含水量比油松纯林增加0.91 g·kg-1、比刺槐纯林增加0.55 g·kg-1;(2)混交林18年后土壤容重比油松纯林减少0.13 g·cm-3、比刺槐纯林土壤容重减少0.10 g·cm-3;(3)混交林土壤有机质比纯林增加0.54 mg.kg-1~1.48 mg·kg-1、土壤碳酸钙含量比纯林减少0.43 mg·kg-1~1.09 mg.kg-1、土壤有效氮比纯林增加6.4 mg·kg-1~19.4 mg·kg-1、土壤有效磷比纯林增加0.36 mg·kg-1~1.37 mg·kg-1、土壤有效钾比纯林减少6.90 mg·kg-1~23.90 mg·kg-1,土壤CEC含量比纯林增加0.23 mg·100 g-1~0.85 mg·100 g-1;(4)混交林林冠面积、林冠厚度、林冠水分截留率分别比纯林提高47.83%~78.95%、40.63%~73.08%、6.15%~8.32%,枯落物饱和持水量是纯林的1.62倍~4.22倍;(5)混交林中油松的树高、胸径比纯林分别提高24.7%和27.35%,混交林年均利润是纯林的7.12倍。     

有机肥替代不同比例化肥对麻竹笋产量的影响

在福建省南靖县开展了麻竹笋用林有机肥替代化肥的田间试验,采取氮总量控制,设置有机氮替代不同比例无机氮的试验处理,分析了各处理之间出笋数量和竹笋产量的差异性。结果表明,在总氮施入量一定的情况下,不同比例的有机氮施入量对增加出笋数量和竹笋产量的影响排序表现为67%>0%>100%>50%>CK>33%;当有机氮施入量占67%时出笋的数量和产量分别比单施化肥增加6.1%和10.3%,对促进麻竹笋生长和产量提升最明显。     

广东省三种典型经济林地土壤性状和养分储量研究

经济林作为一种重要的林分类型,对于促进林业产业发展和林农增收具有重要作用。为了了解经济林地的土壤肥力状况,以促进经济林的高产稳产和可持续经营,选取广东省内三种典型的经济林(包括板栗林、油茶林、笋用麻竹林),对此三种经济林地的土壤孔隙性、持水量等物理性质及氮、磷、钾等养分含量和储量进行了测定与分析。测定结果表明:板栗林地的土壤容重较大,其孔隙度为40.30%~55.99%,田间持水量在208.37~241.29 g·kg-1之间,土壤中的有机质、氮素含量偏低,磷和钾极度缺乏,0~60 cm土层中的有机碳和氮、磷、钾储量分别为70.50与11.25、2.70、113.48 t·hm-2;油茶林地的土壤容重较小,其土壤孔隙度为49.73%~53.58%,田间持水量在313.90~397.61 g·kg-1之间,土壤中的氮和钾元素含量偏低,磷元素极度缺乏,0~60 cm土层中的有机碳和氮、磷、钾储量分别为40.91与7.13、1.94、84.97 t·hm-2;笋用竹林地的土壤容重不大,其土壤孔隙度为46.70%~48.16%,田间持水量在269.11~297.85 g·kg-1之间,土壤中的氮素含量丰富,而钾素含量很低,磷元素较为缺乏,0~60 cm土层中的有机碳和氮、磷、钾储量分别为69.54与12.68、2.93、83.18 t·hm-2。分析结果表明:三种经济林地土壤中的磷与钾元素均缺乏,施肥时应注重磷钾肥的施用。     

MSPD-GC-MS/MS法测定竹笋中26种有机氯农药残留量

以基质固相分散-气相色谱-串联质谱法(先将粉粹的竹笋样品经弗罗里硅土基质固相分散技术净化,然后用20 m L丙酮—正己烷溶液(1+2,v/v)淋洗,GC—MS/MS检测,外标法定量)检测竹笋中26种有机氯农药残留量。结果表明:26种有机氯农药在5~200μg/m L范围内线性良好,相关系数均大于0.99。在0.01~0.1 mg/kg浓度范围内,26种目标物的平均加标回收率为81.1%~108.9%,相对标准偏差在3.3%~9.5%。该方法具有较好的准确度和精密度,各项技术指标均能满足竹笋中26种有机氯农药的检测需要。     

Effect of removal of logging residue on nutrient leaching and nutrient pools in the soil after clearcutting in a Norway spruce stand

Following clearcutting applying the conventional stem-only harvesting method in a Norway spruce (Picea abies (L.) Karst.) stand and different levels of removal of logging residue, the nutrient fluxes from the heaps of logging residue and from the O horizon were monitored over four growing seasons and the soil nutrient pools were determined. Three levels of removal of logging residue were carried out using (i) conventional stem-only harvesting (no residues removed); (ii) residues removed; and (iii) removal of branches (foliage left on site). The heaps of logging residue were a minor source of inorganic N entering the soil in the water percolating through the heaps, but they were a significant source of organic N, P, Ca, Mg, and especially K. Nutrient fluxes from the O horizon were in general greater under the heaps of logging residue as compared to soils without overlying logging residue. The leaching of inorganic N from the O horizon under the heaps of logging residue resulted in a net loss of these compounds, while the O horizon without overlying logging residue gained N. The removal of logging residue significantly decreased the extractable K pools in the soil while it or conversely, the presence of residue heaps had no significant effect on the pools of organic matter and the pools of N, P, Ca, and Mg in the O horizon and in the 0–10 cm soil layer. The results show that the short-term effects of logging residue on nutrient dynamics in the soil can be complex and difficult to interpret in terms of site productivity as there are changes in the nutrient fluxes, which imply the opposite effects on site productivity. However, the results do indicate that, in the short-term, the removal of logging residue does not impair pools of N in the soil nor site productivity on sites where the availability of N limits productivity.     

日本冲绳的经济林栽培

日本冲绳县由160多个岛屿构成,是日本唯一的亚热带海洋性气候地区,气候特点与中国南方有些相似。为了解经济林树种在日本冲绳的分布情况、栽培方式和管理技术,取长补短,促进我国经济林的发展,就日本冲绳县的经济林树种及其栽培情况进行了为期6个月的调查研究,结果表明:日本冲绳县以绿化、观赏栽培的经济林树种较多,大棚和野外栽培的经济林树种较少;土壤施肥使用的是长效复合肥、发酵有机肥、腐熟的农家肥、尿素等种;病虫害防治主要采用有机的、生物的、物理的手段来控制病虫害的发生与蔓延,减少农药尤其是剧毒农药的使用,以生产有机果品。     

蚯蚓和食用菌废渣对土壤的综合改良作用

将食用菌废渣按不同比例加入土壤中（废菌渣∶土壤分别为0∶5、1∶5、2∶5、3∶5、4∶5和5∶5）,并放入蚯蚓,以此研究食用菌废渣和蚯蚓对土壤改良效果。结果表明,食用菌废渣和蚯蚓在培肥土壤和改善土壤结构中发挥重要作用,土壤中的有机质、全氮和全钾的含量得到增加,土壤团粒结构和容重等理化性质得到良好改变,并且随着废渣比例的增加,改良效果呈上升趋势。     

凉水自然保护区红松人工林土壤真菌

2001年5～9月，在黑龙江省小兴安岭凉水自然保护区红松人工林下设立临时标准地，采用“之”字形路线及土壤剖面取样法多点采集土壤样品，并用马铃薯葡萄糖琼脂培养基(PDA)、查氏琼脂培养基(CzA)分别进行菌株的分离、培养、纯化，初步鉴定出14个不同属的土壤真菌，其中包括1个中国新记录种。即链孢轮枝孢(Verticillium catenulatum)。     

海南4种典型林分土壤化学性质比较研究

保持和提高土壤质量是实现林业可持续发展的前提.森林封不仅起着支持和固家林森林生长的作用,而县供给林森林在生长发育过程中所需要的营养与环境条件.     

Response of litter decomposition and soil C and N transformations in a Norway spruce thinning stand to removal of logging residue

Increasing demand for production of bioenergy has led to an interest in forest management which uses logging residue from both clear-cuttings and thinning stands. The aim of this study was to investigate the effects of removal of logging residue in a thinning Norway spruce stand on (1) litter decomposition and (2) soil microbial processes in C and N cycling and the quality of soil organic matter. The study site was a 40-year-old Norway spruce stand growing on a relatively fertile site. During thinning, logging residue was either removed (whole-tree harvest) or left on the site (stem-only harvest). Different types of material in the logging residue, from main branches to needles, were weighed separately into mesh bags. The bags were placed above the moss layer in the whole-tree harvest treatment and in the logging residue layer in the stem-only harvest treatment, and decomposition was monitored for 5 years after treatment. From the humus layer, samples were taken 10 years after treatment. Harvest method affected the mass loss of the litter material very little but the C-to-N ratio of the remaining material was slightly higher in whole-tree harvest than in stem-only harvest, particularly in the needle material. In the humus layer samples, taken 10 years after treatment, the rate of C mineralization was lower in whole-tree harvest than in stem-only harvest; also the rate of net N mineralization and the amounts of C and N in the microbial biomass tended to be lower, although not statistically significantly. Removal of logging residue had no effect on pH (pHH₂O$\text{p}{\text{H}}_{{\text{H}}_2\text{O}}$ 3.9 in both treatments) or C-to-N ratio (28 in both treatments) in the humus layer. The concentrations of total water-soluble phenols and an important group of phenols, condensed tannins, were both lower in the humus layer of whole-tree harvest than in that of stem-only harvest. Concentrations of sesqui-, di- or triterpenes in the humus layer were similar in both treatments. In conclusion, 10 years after harvest, soil microbial activities and organic matter characteristics in whole-tree harvest differed from those in stem-only harvest.     

Fehlermöglichkeiten bei Rückstandsuntersuchungen von Gemüse und Obst- bedingt durch die Probenahme

Mistakes in the results of residue analysis in vegetables and fruits based on samples Mistakes in the results of residue analysis can be separated into mistakes of sample-taking and those of analysing. The mistakes of sample-taking can be avoided when the sample represents the contents of the whole material which is to be analysed in percent. But this is an ideal case.In two examples, lettuce and leek, it is demonstrated that the pesticides are not in the same amount distributed at the different zones of the plant, the differences in the amounts can be, in the case of lettuce after application of quintozene, more than a fourtyfold amount or, in the case of leek after application of mancozeb, a twentyfold amount. Furthermore, the residues can be different from one plant individual to another demonstrated at cherries and radishes. The differences may be caused either by different application techniques or, for example, by different weight of individuals of the same species. Also, different habitus and growth can lead to different residues from one plant individual to another. When the plants take up the pesticides from the soil, a different pesticide distribution in the areas of the soil can also give rise to different residue values.Therefore, the man (engineer or analyst) who takes the samples, must take care for:1. taking the samples symmetrically from the field or from bottom to top of the trees2. chosing those plant individuals to give the labour sample which represent the average weight and the average habitus of the individuals. If plant individuals are analysed which take up the pesticides from the soil, the area from which the sample is derived, must be given.From all points shown, there is clear that a range of disseminating values which can be more than 100% must accounted in the values of residue analysis.     

土壤微生物生物量及其影响因素研究

土壤微生物生物量的养分贮量比土壤有机质的小,但它既是植物所需养分的有效来源,还是养分的临时贮库。本文根据国内外研究结果综述了一些影响土壤微生物生物量动态的因素。这些因素主要包括 C 和 N 的限制、残留物和营养物质的经营、植物种类、土壤质地、土壤湿度和温度等。通过细致分析,我们认为未来研究应着重于探讨土地利用变化对热带和亚热带土壤微生物生物量的影响。参 55。     

有机磷和氨基甲酸酯类农药在蔬菜中的多种残留组分的分析

根据大口径毛细管柱容量大，柱效高这一特点，用有机溶剂提取、凝结净化和硅胶柱层析相结合的方法对样品进行净化，以OV-101大口径石英毛细管柱为分析柱，对敌敌畏、速灭威、叶蝉散等十余种农药在蔬菜中残留的多种组分进行测定，其方法快速、准确、灵敏度高。最低检出浓度低于联合国卫生组所规定的最大残留量2-3个数量级，满足了对食品中农药多种残留组分的分析要求。     

Modelling the effects of forest management intensification on base cation concentrations in soil water and on tree growth in spruce forests in Sweden

The study investigated the effects of forest residue extraction on tree growth and base cations concentrations in soil water under different climatic conditions in Sweden. For this purpose, the dynamic model ForSAFE was used to compare the effects of whole-tree harvesting and stem harvesting on tree biomass and the soil solution over time at 6 different forest sites. The study confirmed the results from experimental sites showing a temporary reduction of base cation concentration in the soil solution for a period of 20–30 years after whole-tree harvesting. The model showed that this was mainly caused by the reduced inputs of organic material after residue extraction and thereby reduced nutrient mineralisation in the soil. The model results also showed that whole-tree harvesting can affect tree growth at nitrogen-poor forest sites, such as the ones in northern Sweden, due to the decrease of nitrogen availability after residue removal. Possible ways of reducing this impact could be to compensate the losses with fertilisation or extract residue without foliage in areas of Sweden with low nitrogen deposition. The study highlighted the need to better understand the medium- and long-term effects of whole-tree harvesting on tree growth, since the results suggested that reduced tree growth after whole-tree harvesting could be only temporary. However, these results do not account for prolonged extraction of forest residues that could progressively deplete nutrient pools and lead to permanent effects on tree growth.