不同有机物料接种蚯蚓对设施菜地土壤 培肥及作物生长的影响

设施蔬菜栽培长期施用过量化肥,往往导致土壤质量退化及作物产量降低等问题。因此,采用生态友好的农业生产方式已成为农业可持续发展的趋势。本研究在野外调控试验的第3年采集作物和土壤,研究了施用不同有机物料条件下,接种赤子爱胜蚓(Eisenia foetida)对设施菜地土壤性质和作物生长的影响。结果表明,在不同有机物料施用下接种赤子爱胜蚓均显著地提高了黄瓜和菠菜的产量,其中在施用腐熟牛粪+食用菌渣条件下接种赤子爱胜蚓效果最显著。此外,在腐熟牛粪和腐熟牛粪+食用菌渣施用条件下,接种赤子爱胜蚓显著地提高土壤的硝态氮(NO3–-N)、团聚体平均重量直径(MWD)、微生物生物量碳(MBC)、微生物生物量氮(MBN)和代谢熵(q CO2),而在施用商品有机肥的处理中,接种赤子爱胜蚓仅显著地提高了土壤NO3–-N和q CO2。本研究促进了对蚯蚓在设施农业生态系统中服务功能的理解,并为设施农业生产提供了理论基础。     

赤子爱胜蚓谷胱甘肽和丙二醛含量变化指示重金属污染土壤的生态毒性

为探讨赤子爱胜蚓谷胱甘肽(GSH)和丙二醛(MDA)含量变化对重金属污染土壤生态毒性的指示作用,在试验室模拟条件下,利用人工土壤和自然土壤,研究了重金属含量与蚯蚓GSH和MDA含量变化的剂量效应关系。结果显示,在人工土壤试验中,Cu可诱导蚯蚓GSH和MDA含量上升,暴露2 d、7 d、14 d后,Cu浓度与蚯蚓GSH含量的相关系数分别为0.556、0.807和0.775,与MDA含量的相关系数分别为0.760、0.672和0.544,均存在显著的剂量效应关系(p<0.05)。自然土壤试验结果显示,赤子爱胜蚓的GSH和MDA含量与土壤Cu全量的偏相关系数分别为-0.830(p<0.001)和-0.599(p<0.05),与Cd全量的偏相关系数分别为-0.697(p<0.05)和-0.690(p<0.05)。同时发现,赤子爱胜蚓GSH含量变化对土壤重金属响应的敏感性要高于MDA。     

蚯蚓种群特征及其对土壤肥力指示作用研究

采用田间调查方法,对华北盐渍改造区7种土地利用方式下的蚯蚓种群特征的变化进行详细调查,分析土地利用方式对蚯蚓种群造成的影响,同时探讨了不同土地利用方式下土壤肥力的差异,并对蚯蚓种群特征与土壤化生物学性质的相关性进行研究。结果表明:蚯蚓的物种数、种群密度、生物量、年龄结构及Shannon-Weiner(H’)多样性指数,与土壤化学及生物学性质的大部分指标具有显著的相关性,对不同土地利用方式下的土壤肥力状况有一定的响应关系。     

不同生活型蚯蚓蚓粪化学组成及其性状的研究

蚓粪已经渐渐成为国内外研究者所关注的一个焦点,而对蚓粪化学成分及性状的研究也逐渐引起了人们的注意.本文研究比较了两种不同生活型蚯蚓蚓粪和对照土壤之间的化学组成及性状的异同.结果表明:蚓粪和对照土壤相比,有着更高的pH和电导率值,且差异显著(P＜0.05);蚓粪比对照土壤有着更多的碳水化合物和更少的多酚类物质,差异分别达31.36～ 33.81 mg/kg和4.28 ～ 5.08 mg/kg;同时,蚓粪内酸解氨基酸含量要比对照土壤高出3.84～5.06mg/g;植物激素GA3相对于对照土壤增幅达35％～ 114％,而IAA的增幅则为78％～236％.在相同的环境下,同样生物量的环毛蚓(威廉环毛蚓)和爱胜蚓(赤子爱胜蚓)对蚓粪pH值、碳水化合物和多酚含量的作用无显著差异(P＞0.05);对蚓粪电导率、植物激素和氨基酸含量的影响爱胜蚓要显著大于环毛蚓.总之,蚓粪的pH值、电导率和化学组成与对照土壤相比都有着显著的差异,不同生活习性的蚯蚓蚓粪也会有着一定的不同.     

蚯蚓作用下土壤化学组成和性状的动态变化

通过室内培养试验研究赤子爱胜蚓(Eiseniafoetida)和威廉环毛蚓(Metaphire guillelmi)对土壤化学组成和性状的动态影响.结果表明:接种蚯蚓可显著提高土壤pH和电导率;蚯蚓作用49 d后土壤化学组成也发生明显变化,接种赤子爱胜蚓和威廉环毛蚓处理的土壤碳水化合物含量分别比对照增加43.22,44.76 mg/kg,酸解氨基酸含量分别增加15.34,12.52 g/kg,植物激素GA3含量分别增加11.21,13.68mg/kg,IAA含量分别增加8.99,8.81mg/kg,而多酚含量却显著降低了7.79,7.48mg/kg.不同处理土壤化学组成和性状随时间变化趋势各有不同,2种蚯蚓作用下,土壤pH和碳水化合物含量均在前7d急剧增加,之后变化趋于平缓;而土壤多酚含量在前7d显著降低,此后也趋于平缓;土壤植物激素GA3含量在前35 d持续增加,而后无显著变化;土壤植物激素IAA、电导率和氨基酸含量随培养时间增加而持续增长,直至培养结束(49 d).     

纳米零价铁(nZVI)对蚯蚓-微生物-土壤生态系统的毒性效应研究

为解决土壤重金属污染问题,纳米零价铁(nZVI)被广泛应用且备受关注,而nZVI对土壤无脊椎动物、土壤质量、微生物群落等的潜在影响缺乏系统的研究。本文以赤子爱胜蚓(Eisenia foetida)[蚯蚓密度为0、10条?kg-1(土)]为研究对象,探讨不同浓度nZVI (nZVI土壤质量为0、0.05%、0.25%和0.50%)暴露15 d、30 d和45 d后,蚯蚓-微生物-土壤生态系统的响应,为评价nZVI的环境安全性提供参考。结果表明,暴露45 d后, nZVI对蚯蚓存活率和生物量无显著影响, 0.50%nZVI处理的蚯蚓存活率和体内MDA含量与15 d相比分别降低27.66%和0.86 nmol?g-1;而蚯蚓生物量和CAT活性分别增加1.20倍和2.62倍。门或属水平下, nZVI对土壤微生物相对丰度、多样性指数和丰度指数无显著影响;与无添加nZVI处理相比,蚯蚓介导下0.50%nZVI处理土壤中大团聚体(250μm)所占比例、团聚体平均重量直径和速效磷含量分别显著升高15.69%、12.59%和21.20%。蚯蚓介导下nZVI处理中土壤大团聚体所占比例、团聚体平均重量直径显著高于无蚯蚓投加的nZVI处理,可见, nZVI胁迫下蚯蚓活动极显著提高土壤团聚体结构的稳定性(P0.01)。本研究发现长期暴露nZVI对土壤微生物群落特征无显著影响,但可以促进蚯蚓的生长,从而进一步提高了土壤营养元素的生物有效性,为nZVI应用于污染修复与治理的环境安全性评估提供了科学依据。     

氯化镉、马拉硫磷和乙草胺对赤子爱胜蚓的复合急性毒性

以赤子爱胜蚓(Eisenia fetida)为试验动物, 选取氯化镉、马拉硫磷和乙草胺作为污染物, 通过人工土壤法研究了3种污染物在5种比例两种污染物复合条件下对蚯蚓的急性毒性。研究结果表明, 3种污染物在两两复合污染时的作用类型以拮抗为主, 仅在镉浓度19.46 mg·kg^-1和乙草胺175.15 mg·kg^-1 (1︰9)复合类型是相加作用, 说明复合污染生态毒理效应与污染物的化学性质和浓度水平均相关。从蚯蚓活体体重减少情况看, 在复合污染条件下, 污染物对蚯蚓生长的影响与单一污染的结果类似, 马拉硫磷对赤子爱胜蚓的影响最大, 乙草胺次之, 而氯化镉的影响最小。     

全灭菌环境下蚯蚓和堆肥对土壤五氯酚老化过程的影响

通过全灭菌环境下的土壤五氯酚（PCP）污染模拟实验,分别测定水提取态、乙醇提取态、腐殖质固定态以及蚯蚓生物累积态PCP的变化,研究添加两种不同蚯蚓品种（赤子爱胜蚓和壮尾环毛蚓）和堆肥对土壤PCP老化过程的影响。结果显示,在42d的培养期内,水提取态PCP在全灭菌土壤对照和添加灭菌堆肥的处理中随时间推移逐渐下降,存在明显的老化效应。在蚯蚓处理中,水提取态PCP呈现先下降后上升的趋势,说明蚯蚓促进土壤PCP的解吸附,这主要与蚯蚓的生物扰动作用以及调节土壤pH趋向中性的作用直接相关。培养结束时,蚯蚓能够有效促进土壤PCP向腐殖质固定态转化,并进一步促进PCP的去除,这与蚯蚓提高土壤腐殖质的含量,促进PCP的化学还原转化作用以及蚯蚓自身对PCP的消解作用有关。壮尾环毛蚓比赤子爱胜蚓更能有效促进PCP的转化与去除,这与两者的生活习性不同有关。灭菌堆肥对全灭菌土壤PCP向其他形态转化的影响不显著。     

菊糖对蚯蚓粪肥性状的影响及调控过程

通过蚯蚓堆肥试验,探讨菊糖对蚯蚓的益生作用及高活力蚯蚓粪肥的形成过程,可为滩涂生态农牧化模式构建及障碍土壤修复提供理论依据.以牛粪、赤子爱胜蚓(Eisenia fetida)和菊糖为材料,设置纯牛粪养殖蚯蚓(EM)和添加菊糖的牛粪养殖蚯蚓(IEM)处理,养殖周期为40 d,每隔10 d采样分析,研究了牛粪–蚯蚓肠道内容...     

水旱轮作后免耕水稻土微生物数量和生物量的变化特征研究

土壤微生物数量和生物量能迅速反映土壤肥力和土壤质量的演变趋势。通过野外调查和室内分析,研究了水旱轮作后,不同免耕年限土壤微生物数量和生物量的变化特点。结果表明:水旱轮作后,免耕耕层(0～20cm)土壤微生物数量、生物量P和生物多样性显著低于常规耕作,而微生物生物量C和N显著高于常规耕作;随着免耕年限延长,生物多样性、微生物生物量C和N在免耕7～8年时最低;免耕0～5cm土壤微生物数量和生物量显著高于5～10cm,而常规耕作0～5cm和5～10cm土壤微生物数量和生物量无显著差异。     

Allometric estimation of earthworm ash-free dry mass from diameters and lengths of select megascolecid and lumbricid species

We present novel length to ash-free dry mass and preclitellar diameter to ash-free dry mass allometric equations for seven earthworm species from the families Megascolecidae and Lumbricidae, all of which are exotic and most of which are of ecological concern in North America: Eisenia hortensis, Eisenia fetida, Dendrodrilus rubidus, Lumbricus rubellus, Octolasion sp., Amynthas hilgendorfi, and Perionyx excavatus. We also present a length-biomass allometric equation for one enchytraeid, Mesenchytraeus sp. All relationships between length and biomass, and diameter and biomass were statistically significant at the species and family level (P<0.001). The predictive powers of these allometric regressions (as coefficients of determination, r²) were species-specific, and ranged widely from 0.27 to 0.93. Length-biomass regressions provided more predictive power and precision overall than preclitellar diameter-biomass calculations at both the species and the family levels. An ANCOVA followed by orthogonal contrasts determined that, while the slopes of these regressions did not differ significantly between the two earthworm families, significant differences in slopes of length-biomass regressions existed among species within families, indicating the utility of having species-level equations for accurate biomass predictions. With these allometric relationships, we aim to improve the estimation of earthworm biomass in order to facilitate investigations of how exotic-invasive earthworm species impact soil ecosystems.     

Sensitivity of <Emphasis Type="Italic">Eisenia fetida</Emphasis> in comparison to <Emphasis Type="Italic">Aporrectodea caliginosa</Emphasis> and <Emphasis Type="Italic">Lumbricus terrestris</Emphasis> after imidacloprid exposure. Body mass change and histopathology

Purpose  

The use of only one or a few species—representing an entire taxon—in ecotoxicological standard tests poses risk of underestimating the impact of toxicants on the environment. In earthworm ecotoxicity tests, the species Eisenia fetida or Eisenia andrei are commonly used, and there is evidence that these species respond relatively insensitive towards environmental pollution. With the present study, we wanted to evaluate the risk of underestimating effects of the insecticide imidacloprid in soil organisms by comparing E. fetida with two other earthworm species (Aporrectodea caliginosa and Lumbricus terrestris) regarding their sensitivities towards soil contaminated with this widely used insecticide.     

Impact of landspread sewage sludge and earthworm introduction on established earthworms and soil structure

Summary Sewage sludge was applied to twelve 4-m² plots in two forest (mixed hardwood, Norway spruce plantation) site and one old field site. The earthworm Eisenia fetida was introduced to half the control and half the treated plots. Earthworm populations were sampled by formalin extraction and hand-sorting five times in the year following treatment. One year after treatment, soil samples were wet-sieved and water-stable aggregate size-class arrays were determined.The dominant earthworm in the study site, Lumbricus terrestris, increased in density and mean individual biomass in response to sludge treatment in mixed hardwood and old field plots. In the Norway spruce plots, L. terrestris increased in individual biomass but decreased in density following sludge application. The density of the introduced E. fetida rapidly declined in all control plots. One year after introduction, E. fetida was found only in the sludge-treated Norway spruce plot. The introduction of E. fetida with sludge decreased the density and biomass of L. terrestris in the hardwood plots.Sludge treatment increased the percentages of 4-mm diameter water-stable aggregates in old field and hardwood plots. The addition of E. fetida with sludge in the hardwood plots generated no increase in 4-mm water-stable aggregates. In the old field, sludge + E. fetida increased the 4-mm water-stable aggregates. Little change in water-stable aggregates in response to either treatment combination was seen in the Norway spruce site.     

Stress protein response (Hsp70) and avoidance behaviour in Eisenia fetida, Aporrectodea caliginosa and Lumbricus terrestris when exposed to imidacloprid

Purpose  

The earthworm species Eisenia fetida and Eisenia andrei are commonly used in ecotoxicological standard tests. In the present study, we compared the sensitivity of E. fetida with that of two soil-dwelling earthworm species (Aporrectodea caliginosa and Lumbricus terrestris) in order to evaluate the capacity of E. fetida to predict effects of the insecticide imidacloprid. Responses were compared using two endpoints, a biochemical (changes in heat shock protein level (hsp70)) and a behavioural (avoidance behaviour).     

Population dynamics of the earthworm Amynthas alexandri (Annelida: Megascolecidae) in a Kumaun Himalayan pasture soil

Ecological studies on earthworms were conducted in a Kumaun Himalayan pasture soil. The C:N ratio in the soil declined with increasing depth. A combination of hand-sorting and formalin application was used to sample the earthworms. Three species, Amynthas alexandri, A. diffringens (Megascolecidae), and Eisenia fetida (Lumbricidae) were found. Of the 13310 individuals collected, 99.9% were A. alexandri. The maximum density (138.8 m^-2) and biomass (25.2 g m^-2) were recorded in the wet season. More than 60% of the total earthworm numbers and biomass were recorded at 0–10 cm in depth. The mean yearly ratio of clitellate to aclitellate worms was 1:7.3.     

Earthworm response to rotation and tillage in a Missouri claypan soil

 Agricultural management practices affect earthworm populations. A field experiment was conducted to determine the effect of two rotations and two tillage systems on earthworm population density and biomass in a claypan soil. The rotations were soybean/corn and wheat/corn, and the tillage systems were conventional tillage (chisel plowed and disked) and no-tillage. Earthworm and soil samples were collected in fall 1995, spring 1996, and fall 1996. Aporrectodea trapezoides and Diplocardia singularis were the species identified at the site. A. trapezoides accounted for 92–96% of the total earthworm population density and D. singularis accounted for only 4–8%. In a no-till system, soybean/corn rotation resulted in significantly greater population density of A. trapezoides compared with the wheat/corn rotation. Crop residue quality (low C:N ratio) and quantity were important factors in increasing A. trapezoides population density and biomass. Conventional tillage markedly decreased population density and biomass of both earthworm species. Our results suggest that rotation and tillage significantly affect earthworm population density and biomass. Received: 6 June 1998     

Effect of management practices and cropping systems on earthworm abundance and microbial activity in Sanborn Field: a 115-year-old agricultural field

Sanborn Field, an agricultural demonstration field at the University of Missouri-Columbia, has over 100 years of cropping histories and management practices implemented at this site. We examined the effect of these cropping systems and management practices on earthworm populations and microbial activity. A field experiment was conducted to characterize and quantify earthworms and to determine the microbial activity in the same selected plots. We sampled 14 plots at the site, six of which were the original plots established in 1888 with the same cropping histories and management, and eight of which had been modified over the years to accommodate changing farmer needs and scientific questions. Earthworms and soil samples were collected in the spring and fall of 1999. Aporrectodea trapezoides, Aporrectodea caliginosa, and Lumbricus terrestris were the dominant species found in this field. Lumbricus terrestris was commonly associated with the no-tillage plot at Sanborn Field. Due partly to soil moisture conditions, most of the species were found and identified during the spring. Microbial activity, as expected, was greatest during the spring. Manure, no-tillage and crop rotations that include legumes had the greatest earthworm abundance and microbial activity. In general, where no fertility treatments were added to soil or where food sources were lacking, earthworm abundance decreased significantly. The abundance of earthworms found in this field reflected the cropping history and management practices used recently and within the last 100 years. In most cases, microbial activity showed similar trends as earthworm density. However, some dynamic microbial transformations, like nitrification, do not always follow the same trend as potential soil quality biotic indicators. Earthworms, along with microbial activity, may serve as useful soil quality indicators in sustained and short-term field trials.     

Effects of traditional and biodynamic farmyard manure amendment on yields,soil chemical,biochemical and biological properties in a long-term field experiment

We studied the effects of applications of traditionally composted farmyard manure (FYM) and two types of biodynamically composted FYM over 9 years on soil chemical properties, microbial biomass and respiration, dehydrogenase and saccharase activities, decomposition rates and root production under grass-clover, activity and biomass of earthworms under wheat, and yields in a grass-clover, potatoes, winter wheat, field beans, spring wheat, winter rye crop rotation. The experiment was conducted near Bonn, on a Fluvisol using a randomised complete block design (n=6). Our results showed that plots which received either prepared or non-prepared FYM (30 Mg ha^–1 year^–1) had significantly increased soil pH, P and K concentrations, microbial biomass, dehydrogenase activity, decomposition (cotton strips), earthworm cast production and altered earthworm community composition than plots without FYM application. Application of FYM did not affect the soil C/N ratio, root length density, saccharase activity, microbial basal respiration, metabolic quotient and crop yields. The biodynamic preparation of FYM with fermented residues of six plant species (6 g Mg^–1 FYM) significantly decreased soil microbial basal respiration and metabolic quotient compared to non-prepared FYM or FYM prepared with only Achillea. The biodynamic preparation did not affect soil microbial biomass, dehydrogenase activity and decomposition during 62 days. However, after 100 days, decomposition was significantly faster in plots which received completely prepared FYM than in plots which received no FYM, FYM without preparations or FYM with the Achillea preparation. Furthermore, the application of completely prepared FYM led to significantly higher biomass and abundance of endogeic or anecic earthworms than in plots where non-prepared FYM was applied.     

Effects of Epigeic Earthworms on Decomposition of Wheat Straw and Nutrient Cycling in Agricultural Soils in a Reclaimed Salinity Area:A Microcosm Study

Earthworms,one of the most important macroinvertebrates in terrestrial ecosystems of temperate zones,exert important influences on soil functions.A laboratory microcosm study was conducted to evaluate the influence of the earthworm Eisenia fetida on wheat straw decomposition and nutrient cycling in an agricultural soil in a reclaimed salinity area of the North China Plain.Each microcosm was simulated by thoroughly mixing wheat straw into the soil and incubated for 120 d with earthworms added at 3 different densities as treatments:control with no earthworms,regular density(RD)with two earthworms,and increased density(ID)with six earthworms.The results showed that there was no depletion of carbon and nitrogen pools in the presence of the earthworms.Basal soil respiration rates and metabolic quotient increased with the increase in earthworm density during the initial and middle part of the incubation period.In contrast,concentrations of microbial biomass carbon and microbial biomass quotient decreased in the presence of earthworms.Earthworm activity stimulated the transfer of microbial biomass carbon to dissolved organic carbon and could lead to a smaller,but more metabolically active microbial biomass.Concentrations of inorganic nitrogen and NO₃^--N increased significantly with the increase in earthworm density at the end of the incubation(P<0.05),resulting in a large pool of inorganic nitrogen available for plant uptake.Cumulative net nitrogen mineralization rates were three times higher in the ID treatment than the RD treatment.