北京市农业区不同使用类型土壤中二噁英类分析

2005年6—7月采集了北京市农业区不同使用类型土壤样品24个,分别为蔬菜地8个、粮地8个、果园地8个,采用高分辨气质联机对17种二噁英类进行了分析.结果表明:所有样品中二噁英浓度范围为,0.26—5.74(平均值为1.51)pgI-TEQ.g-1;蔬菜地浓度范围为,0.26—5.62(平均值1.75)pgI-TEQ.g-1;粮地浓度范围为,0.45—5.74(平均值2.02)pgI-TEQ.g-1;果园地浓度范围为,0.34—2.02(平均值0.73)pgI-TEQ.g-1;三种类型中粮食地浓度最高,其次为蔬菜地,果园地浓度最低.与国外农业区土壤中的二噁英浓度相比而言,北京市相对较低.所有样品中,样品8和16浓度异常高,但是8.3%(2:24)的高浓度样品数并不代表对人体有害.由于样品24处于垃圾焚烧炉旁边,也对此进行了详细的分析.样品中二噁英类物质形态分布出现了极大的离散性,这表明农田土壤中二噁英可能是多种因素综合作用的结果,例如:除草剂的使用、秸秆等固体废弃物的焚烧、汽车尾气排放等.     

Effects of five insecticides used in apple orchards on Hyaliodes vitripennis (say) (Hemiptera: Miridae)

Abstract

Azinphos‐methyl, carbaryl, dimethoate, phosmet and phosalone were used in apple orchards to manage apple aphid, apple maggot, woolly apple aphid and leaf eating caterpillars. Among the five insecticides evaluated, dimethoate, carbaryl and azinphosmethyl were the most toxic to the nymphs and adults of Hyaliodes vitripennis (Say) from two regions. Phosalone was the least toxic. Nymphs were more resistant than the adults. While the LC₅₀ for dimethoate was 130 ppm for nymphs, it was 3 ppm for adults from St. Jean‐Baptiste‐de‐Rouville. There were also significant differences in the level of resistance between the two regions where the H. vitripennis were collected. At St. Alexandre the LC₅₀ for phosalone on nymphs was 19, 250 ppm whereas, at St. Jean‐Baptiste‐de‐Rouville it was 160, 000 ppm.     

Copper desorption in flooded agricultural soils and toxicity to the Florida apple snail (Pomacea paludosa): implications in Everglades restoration

Copper (Cu) desorption and toxicity to the Florida apple snail were investigated from soils obtained from agricultural sites acquired under the Comprehensive Everglades Restoration Plan. Copper concentrations in 11 flooded soils ranged from 5 to 234 mg/kg on day 0 and from 6.2 to 204 mg/kg on day 28 (steady-state). The steady-state Cu concentration in overlying water ranged from 9.1 to 308.2 microg/L. In a 28-d growth study, high mortality in snails occurred within 9 to 16 d in two of three soil treatments tested. Growth of apple snails over 28 d was affected by Cu in these two treatments. Tissue Cu concentrations by day 14 were 12-23-fold higher in snails exposed to the three soil treatments compared to controls. The endangered Florida snail kite and its main food source, the Florida apple snail, may be at risk from Cu exposure in these managed agricultural soil-water ecosystems.     

不同催花肥对莲雾根际土壤细菌群落多样性的影响

为了解在反季节催花期间不同催花肥处理下莲雾根际土壤细菌群落结构的影响,采用Illumina MiSeq高通量测序技术对细菌16S rRNA V3-V4区进行检测,并结合土壤理化性质,比较分析不施肥（CK）与两种不同浓度施肥处理组（IF组,即无机肥处理组;GM组,即羊粪有机肥处理组）下的根际土壤细菌群落结构多样性.结果表明:①所有样品中共检测到10 925个OTU（operational taxonomic unit,操作分类单元）,包括239 639条有效序列,可分为28个门411个属.②多样性指数分析显示,细菌群落多样性顺序为IFM（中浓度无机肥处理）> GML（低浓度羊粪有机肥处理）> IFL（低浓度无机肥处理）> GMM（中浓度羊粪有机肥处理）> CK（对照）> IFH（高浓度无机肥处理）> GMH（高浓度羊粪有机肥处理）.其中,酸杆菌门（Acidobacteria）、绿弯菌门（Chloroflexi）、变形菌门（Proteobacteria）、放线菌门（Actinobacteria）为主要菌群,所占比例超过总数的67.33%.③不同施肥条件下莲雾根际土壤细菌群落结构特征分析显示,CK、IF组和GM组所特有的OTU数量分别占总数的0.51%、7.08%和2.60%,表明不同肥料的添加对土壤细菌群落多样性产生一定的影响,在IFH和GMH处理下,酸杆菌门的Subgroup_2_norank属与绿弯菌门的JG37-AG-4_norank属的相对丰度最高,分别为13.13%和15.89%.④环境因子的相关性热图分析表明,装甲菌门（Armatimonadetes）、硝化螺旋菌门（Nitrospirae）、酸杆菌门、放线菌门、厚壁菌门（Firmicutes）这五类菌群与不同环境因子的显著性关系如下:装甲菌门群落结构与pH呈现出极显著正相关,硝化螺旋菌门群落结构分别与w（TN）和w（有机质）呈现出显著负相关,酸杆菌门群落结构与w（速效磷）呈现出显著负相关,放线菌门群落结构与w（速效磷）呈现出显著正相关,厚壁菌门群落结构分别与w（速效磷）和w（速效钾）呈现出极显著正相关.研究显示,适量施加无机肥或羊粪有机肥,可以显著提高土壤细菌的丰度和多样性,有利于土壤生态环境的改良与维系.      

稀土元素对梅园主要土壤动物群落结构组成的影响

为阐明不同稀土处理对梅园土壤动物群落组成的影响,采用手拣法、干漏斗法和湿漏斗法对梅园各稀土处理区土壤动物群落组成进行系统调查,共得土壤动物标本8076个,隶属于4门15纲31目.其中昆虫纲物种最为丰富,有12目,占全部种群数的58.41%;;鞘翅目、膜翅目、蜱螨目、双翅目和弹尾纲等5种优势类群占土壤动物个体总数的81.44%.5种稀土处理区中,杂食性土壤动物功能团所占的比例均高于植食性功能团所占的比例,且杂食性土壤动物所占的比例依次为对照区(CK)(La处理区(下同)(Ce区(Pr区(Nd区(Sm区.不同浓度稀土处理区中土壤动物类群和个体数量均随着稀土浓度增加而减少,杂食性功能团所占的比例也高于植食性功能团所占的比例,且杂食性功能团所占的比例依次为对照区(CK)(25区(mg·kg-1处理区,下同)(50区(100区(500区(1000区(2000区(3000区.以Pr处理后的土壤动物物种数多,个体数量大,优势集中性指数高,优势物种优势性极明显,其它4种稀土在类群数、个体数、优势集中性指数和优势类群优势性和Pr规律基本相同,依次为Nd、Sm、Ce和La,但均比CK小.因此,5种稀土及其不同浓度处理区土壤动物群...     

秦岭北麓平原对全球变暖的响应及其对果业发展的影响研究

论文分析了秦岭北麓8县的近41年的气候变化规律,发现该地区气候变化趋势与全国和全球相似,向暖干化方向发展。采用近41年气候特征值对苹果适宜性进行评价,发现该地区并不是苹果生长的适宜区。夏季高温、较高的相对湿度和较短的日照时数是苹果生长的不利因素。结合目前的气候变化趋势,推论出该地区苹果的病虫害将会加重,苹果质量将进一步下降。地区果业发展中,减少苹果栽种面积和优化果品生产结构仍然具有一定潜力。     

耕作和秸秆覆盖对苹果园土壤水分及养分的影响

为了揭示土壤耕作和秸秆覆盖对苹果园土壤保蓄水性能及土壤肥力的影响,研究设置了以土壤耕作(免耕、翻耕、旋耕)为主处理,秸秆覆盖(秸秆覆盖、无覆盖)为副处理的裂区试验,对比分析了各处理果园土壤水分贮量、土壤肥力等性状。结果表明,免耕裸地与翻耕裸地处理的保蓄水效应在果树不同生长期表现不同,在5月份免耕裸地处理1 m土层内土壤贮水量高于翻耕裸地处理,而在10月份免耕裸地处理显著低于翻耕裸地处理;秸秆覆盖各处理1 m土层内土壤贮水量均明显高于无覆盖各处理,耕作与秸秆覆盖相结合在整个土壤水分测定过程中均以免耕秸秆覆盖土壤贮水量最高且较稳定;耕作与秸秆覆盖相结合显著提高了有机质含量,土壤速效肥含量明显增加,各处理以翻耕秸秆覆盖及免耕秸秆覆盖土壤养分含量为最高。在渭北洛川苹果生产基地,采用免耕秸秆覆盖技术能起到较好的保蓄水作用,土壤肥力明显增加。     

太湖流域果园种植面源氮磷输出强度及其定量评估方法

以太湖流域上游地区无锡阳山地区果园种植典型区域为研究对象,通过现场试验,调查了果园种植面源氮磷输出动态变化过程,计算并分析了氮磷输出强度,构建了果园种植面源氮磷输出强度定量评估模型。结果表明:取样监测期间,果园种植径流及淋溶氮磷指标变化幅度均超过200%;果园种植面源氮磷径流输出强度与其淋溶输出的变化一致,径流总氮的输出强度最高(13.201 kg/hm²),淋溶硝酸盐输出强度最大(4.077 kg/hm²);所建立的评估方程能较好地反映降雨量等环境因素对果园种植面源氮磷径流及淋溶输出强度的影响情况,模拟方程的复相关系数均在0.9左右。     

不同措施在防治山地果园水土流失及面源污染中的应用研究

通过施用生物毯、生物带和秸秆覆盖3种措施,模拟人工降雨,测定山地果园的水土流失量,比较不同措施在防治山地果园水土流失中的效果.结果表明,在降雨强度为1.33 mm/min时,与对照相比生物毯和秸秆覆盖能减少50%以上的氮磷流失量,生物带减少氮磷流失量也达到30%以上;在降雨强度为2.33 mm/min时,秸秆覆盖防治水土流失的效果最好;在高降雨强度(2.33mm/min)时,各种措施防治效果降低,但效果仍然明显,对磷的防治效果好于对氮的防治效果,与对照相比生物毯能减少44.5%的磷流失量.山地果园水土流失相当严重,施用生物毯和秸秆覆盖能有效防治山地果园的面源污染.     

The transfer of active ingredients of insecticides and fungicides from an orchard to beehives

This investigation was undertaken to determine whether active ingredients (AIs) of currently recommended plant protection products (PPPs) could be transferred to beehives from apple and pear trees. A field trial was carried out with apple trees of Ligol and Idared variety, and pear trees of Conference variety. For pest and diseases control of fungal origin, recommended PPPs were applied. Samples of flowers from the above-mentioned varieties of fruit trees, of bees, brood and honey from beehives located in their direct neighborhood were collected regularly and analyzed for the presence of lambda-cyhalothrin (an insecticide) and cyprodinil, captan, fluopyram, kresoxim-methyl, penthiopyrad and trifloxystrobin (fungicides). In samples of flowers of Ligol variety, fluopyram residues (on average 0.621 µg single flower^?1) were at the highest levels, whereas in samples of pear flowers of Conference variety, and in flowers of Idared variety, captan residues (on average, respectively, 0.705 and 165.7 µg single flower^?1). In samples of bees and honey, residues of five AIs were detected, and in brood six AIs, whereby in each case captan residues prevailed, respectively, up to 585.2, 51.52 and 126.5 µg kg^?1 bees and honey. In the honey, significantly larger residues of captan were found out than maximum residue level (MRL) for this AI – 103.04% MRL. In the case of any AI, the daily intake did not exceed 0.002% acceptable daily intake (ADI).