可降解生态垫在河滩区造林中对土壤含水量的影响

可降解生态垫是一种新型的苗木培育材料,能有效的减少地面蒸发,控制土壤水分,提高造林成活率。为了检验可降解生态覆盖垫在河滩地造林中对土壤含水量的影响,试验区共设2个处理(有生态覆盖垫、无生态覆盖垫)对降雨后不同时间(1 d、3 d、5 d、7 d)刺槐、油松、元宝枫、蒙古栎、侧柏和铺地柏等林地的土壤含水量进行了调查。结果表明:可降解生态垫抑制地面蒸发效果更为明显;生态覆盖垫对油松林地的保水作用影响最大;阔叶林林地的土壤含水量较针叶林林地小。     

生态垫对河滩造林地土壤温湿度和杂草的影响

 生态垫在华北干旱地区调查季节内,能够明显降低土壤15cm以上的温度,表层温度变化尤为明显,日均温可降低103～138℃,并且不同土壤深度的日温差,都要低于不铺垫的;铺设生态垫后,在初春能够显著地提高土壤0～20cm的含水量,比不铺设的要高出443%,对40cm以下土壤含水量影响不大;生态垫可以有效抑制杂草生长,铺设生态垫后,杂草的盖度、高度、生物量等都要低于不铺垫的,其中杂草种类降低了40%之多,生物量降低99%之多。     

生态垫对油松生长及光合特性的影响

 为了研究生态垫覆盖对林木光合特性的影响,首次将生态垫应用于华北干旱油松造林地。在油松（78年）造林初期,用生态垫覆盖林地,经过2个生长季后对土壤水分及各项光合指标进行测定。结果表明:覆盖生态垫增加了表层0～20cm的土壤含水率0.04%～2.78%（相对增长率0.4%～92.2%）;提高造林成活率5.1%;增加地径年生长量58.5%,促进了林木生长。覆盖可以提高叶片光饱和点下的光合速率10.6%～44.3%;增加光合速率日变化极大值30%;提高生长季Tr极大值45.8%、提高生长季Cond极大值36.0%,但对油松光补偿点及水分利用效率影响并不显著。     

不同覆盖处理对辣椒田间环境及生长的影响

比较不同覆盖处理对田间杂草生长的抑制,对土壤温度、水分、孔隙结构以及辣椒生长情况影响。结果表明,利用银黑膜覆盖较无色透明膜覆盖在抑制田间杂草生长、均衡地温、保持土壤水分与结构及促进辣椒生长等方面优于无色透明膜覆盖。     

生态垫在龙庆峡荒滩植被恢复和重建中应用效果研究

以延庆龙庆峡荒滩生态综合治理示范区为研究对象,通过对铺设和未铺设生态垫林地小气候、自然降尘、土壤水分、林下植物群落及植被生长情况的调查研究,表明生态垫在这种类型造林地上使用,在防止地表风蚀,抑制地表蒸腾,保存土壤水分,提高土壤温度,促进植物生长和群落形成等方面效果明显.     

盛夏覆盖对幼龄茶园土壤温湿度和杂草生长的影响

江南茶区夏季高温少雨,新建茶园易受旱热草害,从而影响茶苗成活率和生长。为了探讨不同覆盖材料在幼龄茶园中保湿、降温、抑制杂草的效果,采用单因素对比试验,设置4个覆盖处理,1个裸地对照,在杭州盛夏高温季节对各处理土壤温度和湿度变化及控草效果进行了比较研究。结果表明:夏季晴热高温季节,黑膜、无纺布和覆草处理均可显著降低土壤温度,减小温度日较差。持续晴热7天和14天时,黑膜和覆草处理土壤含水量显著高于对照组。覆盖均能极显著抑制茶行杂草的生长,其中黑膜和无纺布处理的杂草生长量极显著低于白膜和覆草处理。所有覆盖处理都能极显著降低拨草人工费,最高效的黑膜覆盖处理可以节约8 550元/hm~2,所用工时只有对照组的24.95%,扣除覆盖成本投入,每公顷可以节约6 370元。综合比较各种覆盖材料在降低土壤温度、提高土壤含水量、控制杂草生长及降低除草成本方面的效果,发现黑膜处理效果最好,其次是无纺布和覆草处理。因此,新茶园夏季覆盖材料推荐使用黑地膜、覆草和无纺布。     

两种生态控草措施对丘陵茶园杂草群落及物种多样性的影响

实现丘陵茶园杂草生态控制, 可有效减少茶园土壤水分和养分的消耗, 减少或避免使用化学除草剂.本研究根据生态位先估和生态位竞争原理, 设计覆盖稻草和间种豆科绿肥白三叶草(Trifolium repens)两种杂草生态控制技术, 同时设置清耕对照(CK), 采用小样方多点取样连续两年调查茶园杂草种群数量、生物量、平均株高等指标, 发现茶园共有杂草16科31属31种; 3个处理春季(4月)发生的杂草特征表现为生长速度较慢、生物量小、株高在30 cm以下; 夏季(7月)和秋季(9月)对照的优势恶性杂草多度(Pi)高达0.788和0.759, 稻草覆盖处理分别为0.256和0.420, 间种白三叶草处理恶性杂草种类较少发生(Pi值均低于0.050); 稻草覆盖处理茶园春、夏和秋季杂草物种丰富度(S)、种群多样性(H)、均匀度(J)等指数均高于对照, 优势集中性指数(C)低于对照; 间种白三叶草处理春、夏和秋季杂草总数量和生物量均显著低于对照, 夏、秋季杂草平均株高显著低于对照.结果表明两种生态控草处理措施能改变茶园杂草群落结构, 有效控制杂草的生长.     

不同施用方式下污泥堆肥对土壤性质和草坪生长的影响

为解决城市污泥处理难题,探讨污泥堆肥及其不同施入方式对绿地土壤的改良效果,进行了污泥堆肥绿地土壤改良试验。试验设混合(H)、覆盖(F)、混合+覆盖(HF)3种施入方式,结果表明:不同施入方式均能显著降低绿地土壤容重,提高土壤中有机质、碱解氮、速效钾、有效磷含量,HF和H的改良效果最好;不同施入方式还均能显著促进草坪生长和分蘖,其中HF,F,H处理的分蘖密度分别比对照高45%,37%,32%;F处理的杂草抑制率在96%以上,HF为78%,H处理未能抑制杂草;各施入方式均能显著提高土壤微生物碳和土壤微生物氮含量,改良1年后,F、H和HF的土壤微生物碳含量分别是对照2.4,3.1,3.4倍,微生物氮含量分别是对照的1.7,3.0,2.8倍;与对照相比,HF处理与H处理的土壤脲酶、酸性磷酸酶和蔗糖酶活性均显著提高。     

黑膜与普通膜全覆盖胡麻田间杂草发生规律研究

以陇亚10号为指示品种,观察了不同地膜覆盖条件下胡麻田杂草的发生规律。结果表明,覆盖白色地膜时,胡麻田杂草出苗早、密度高。其中5月26日至6月24日期间杂草生长快,对胡麻生长发育有严重影响。覆盖黑色地膜时,胡麻田杂草均分布在种植穴周围,密度低、生长较慢,5月15日前对胡麻幼苗生长影响不大;5月26日至6月24日期间杂草生长快,对胡麻正常生长发育有影响。露地胡麻田杂草密度明显高于覆盖黑色地膜胡麻田杂草,但不及覆盖白色地膜胡麻田,且生长较慢;5月15日之前对胡麻幼苗生长影响不大,5月26日至6月24日期间杂草密度较高且生长快,对胡麻正常生长发育有严重影响。综合分析认为,覆盖黑色地膜结合种植穴覆土,是胡麻田杂草有效的物理防除措施。     

高麦茬覆盖复播生态效应研究

试验证明,高麦茬覆盖复播技术,具有蓄水保墒、调控地温、培肥改土、抑制杂草等土壤环境效应,同时具有促进夏作物生长发育、提高产量的环境生态效应。与常规耕作复播相比,具有显著的增产效果。     

<Emphasis Type="Italic">Lantana camara</Emphasis> L. (Verbenaceae) invasion effects on soil physicochemical properties

Lantana camara is a recognized weed of worldwide significance due to its extensive distribution and its impacts on primary industries and nature conservation. However, quantitative data on the impact of the weed on soil ecosystem properties are scanty, especially in SE Australia, despite the pervasive presence of the weed along its coastal and inland regions. Consequently, mineral soils for physicochemical analyses were collected beneath and away from L. camara infestations in four sites west of Brisbane, SE Australia. These sites (hoop pine plantation, cattle farm, and two eucalyptus forests with occasional grazing and a fire regime, respectively) vary in landscape and land-use types. Significant site effect was more frequently observed than effect due to invasion status. Nonetheless, after controlling for site differences, ~50% of the 23 soil traits examined differed significantly between infested and non-infested soils. Moisture, pH, Ca, total and organic C, and total N (but not exchangeable N in form of NO₃^-) were significantly elevated, while sodium, chloride, copper, iron, sulfur, and manganese, many of which can be toxic to plant growth if present in excess levels, were present at lower levels in soils supporting L. camara compared to soils lacking the weed. These results indicate that L. camara can improve soil fertility and influence nutrient cycling, making the substratum ideal for its own growth and might explain the ability of the weed to outcompete other species, especially native ones.     

长期不同施肥对玉米田间杂草生物多样性的影响

通过田间小区试验,研究了长期不同施肥对田间杂草总密度、优势杂草组成及生物多样性的影响。结果表明:综合施用N、P、K肥,不仅降低了田间杂草的总密度,降低了优势杂草在群落中的比重,而且有利于维持田间杂草的生物多样性;不施用N或P肥,田间杂草的总密度增大,优势杂草的比重也明显增强,但不利于维持田间杂草的生物多样性。所以,平衡施用N、P、K肥,有利于维持农田生态系统中的生物多样性,并能更好地进行杂草控制。     

林下秸秆覆盖种植大球盖菇对苦驴河源头坡地清水产流的影响

[目的]探索秸秆覆盖种植大球盖菇模式对经济林(尤其是刚刚荒改坡的经济林)清水产流和改土控草的影响,为坡地水源涵养、生态保育、控草保肥提供技术支撑。[方法]在派河上游苦驴河的源头,选取2组不同种类的坡地经济林,利用秸秆覆盖种植大球盖菇技术,在大球盖菇生长的不同时期对该区域坡地水质、土壤有机质和杂草多样性进行分析。[结果]采用秸秆覆盖种植大球盖菇的技术,平均能有效降低该地区水中总氮42.68%～50.47%,总磷45.72%～46.74%和悬浮物(SS)33.41%～36.58%的含量,同时增加土壤有机质的含量,平均增长了10.17%～16.42%,减少该区域杂草多样性和种类,有效降低了该地水肥流失,可在较短时间内无害且快速地增加该区域清水产流能力。[结论]采用秸秆覆盖种植大球盖菇的技术,能有效降低坡地径流水中总氮、总磷和SS的含量,同时增加土壤有机质的含量,减少该区域杂草多样性和种类,起到控制水肥和水土流失作用,在当年荒改坡的坡地上,该作用更加明显。     

Type and time of autumn tillage with and without herbicides at reduced rates in southern Sweden: 2. Weed flora and diversity

The design of integrated weed management (IWM) systems is essential in order to reduce the use of herbicides for crop production. By combining different weed management practices, herbicides may be used at lower doses than normally recommended, while still maintaining acceptable weed population levels. The purpose of this study was to develop tillage strategies, with and without herbicides at reduced rates, appropriate for different weed populations. The influences of type and time of stubble cultivation, harrowing and mouldboard ploughing on the weed flora were followed during 1988–1994 in eight long-term field trials situated in southern Sweden. Spring-sown barley (Hordeum distichon L.) and oats (Avena sativa L.) dominated the crop rotations. Herbicides were either omitted or used at ca. 50% of a full dose. The perennial species Sonchus arvensis L. was favoured by omittance of ploughing but was better controlled by late ploughing not preceded by stubble cultivation; the reduction in the latter treatment being 74%. Stubble cultivation succeeded by ploughing reduced biomass of Elymus repens (L.) Gould. by 90% compared with ploughing solely. Early ploughing reduced the biomass of the species by 50% compared with late ploughing. The species Cirsium arvense (L.) Scop. was highly favoured by early ploughing followed by late autumn harrowing, the biomass of the species being six-fold higher than in other treatments. Compared with other treatments, stubble cultivation favoured four annuals but efficiently controlled three others, while omittance of ploughing favoured six annual and two perennial weed species. Late ploughing not preceded by stubble cultivation favoured four annual and one perennial species, while early ploughing was more efficient than late ploughing in controlling two of the annual species. Influences of treatments on weed species were frequently moderated by interspecific competition resulting in inconsistent response at different sites. Herbicides reduced the number of species by three, from 11 to eight species, averaged across sites and tillage systems. Influences of treatments on diversity were not consistent, since weed floras differed between sites and since some of the species responded inconsistently to tillage and herbicides. This study shows that by utilizing appropriate tillage strategies it is possible at many sites to maintain acceptable weed population levels, although herbicides are used at 50% lower doses than is normally recommended. The timing and type of tillage have to be chosen for being as efficient as possible to the most troublesome weed species at a site.     

Composting of Aerial Parts of Crofton Weed (Eupatorium adenophorum Spreng), the Top Invasive Plant in Southwest China

ABSTRACT

The aerial parts of invasive crofton weed (Eupatorium adenophorum) in Southwest China were used as the main material and fermentated by microbial inoculant Bacillus subtilis to produce bio-organic fertilizer. Results showed that the allelochemicals of crofton weed had no significant negative effect on the activity of B. subtilis. No seeds of crofton weed germinated during the composting period and thereafter. Compared with uncomposted crofton weed, the nitrogen and phosphorus contents in composted crofton weed increased. In addition, the main allelochemical of composted crofton weed, i.e., 9-β-hydroxy-ageraphorone, was significantly reduced. The potassium content remained stable. Furthermore, tomatoes cultivated with bio-organic fertilizer grew better in terms of plant height than those cultivated with uncomposted crofton weed and ordinary red soil. Therefore, crofton weed can be used to produce bio-organic fertilizers, thereby controlling crofton weed infestation.     

The Effect of Temperature on the Viability Of Weed Seeds in Compost

In this study, the effect of different constant temperatures on the viability of weed seed contaminants of municipal composted waste was determined. Seeds of eight weed species were buried in moist compost in small recoverable packets. The seeds were subjected to three constant temperatures, typical of the composting process, removed after 3, 21 and 84 days and their germination and viability determined. At 55°C all of the recovered weed seeds failed to germinate and were found to be non-viable. At 35°C and 45°C an effect of incubation period was noticeable, and it was evident that there were significant differences between species in tolerance to temperature. The study showed that three days at 55°C was sufficient to destroy all the selected weed species. It was concluded that, among the species studied, seeds that survive the composting process do so as a result of localized “cool spots” caused by inefficient turning of the windrow. Alternatively wind blown species could be entering the outer parts of the windrow, immediately prior to packaging.     

Effect of reduced tillage on weeds and soil organisms in winter wheat and summer maize cropping on Humic Andosols in Central Japan

Although reduced tillage (RT) may preserve soil biota and improve the productivity and sustainability of arable lands in temperate regions, the extension of RT is limited by difficulties in controlling weeds. We studied the effect of RT without herbicide application on weed communities and soil biota in a 1-year 2-crop rotation system with winter wheat (Triticum aestivum L.) and maize (Zea mays L.) on Andosols in Japan. RT of the surface 3 cm and conventional moldboard plowing (CT) were conducted before seeding twice per year. For the first 3 years, from autumn 1997 to spring 2000, one field was managed with RT and another with CT. For the second 3 years, from autumn 2000 to spring 2003, RT and CT were conducted in two replicated plots in each field. Weed communities and soil biota were studied in the last 2 years. Dominant weed species in winter wheat cropping were Italian ryegrass (Lolium multiflorum Lam.) in 2002 and common vetch (Vicia angustifolia L.) in 2003, and their biomass was high where RT or CT was continuously conducted. Switching of tillage methods, from RT to CT or vice versa, reduced the biomass of winter weeds. In summer maize cropping, several annual and perennial weed species tended to increase under RT in the second 3 years. However, redroot pigweed (Amaranthus retroflexus L.), the most dominant weed in 2002 and 2003, responded to tillage inconsistently and its biomass was not always increased by RT. Species diversity of winter weeds was decreased by CT conducted in the first 3 years, and that of summer weeds was decreased by CT conducted in the second 3 years. The seedbank in the 0–10-cm soil layer under recent RT was large (7200–16 300 seeds m⁻²) compared with that under CT (2900–7300 seeds m⁻²). The microbial substrate-induced respiration (SIR) and the population densities of nematodes and mites were higher under RT in the second 3 years and were not affected by previous tillage practices. Both were highly correlated with soil total nitrogen. The positive effect of RT on these soil organisms was primarily attributable to the accumulation of organic matter in soil, but not to plant cover as a result of incomplete weed control by RT. Occasional adoption of RT in current CT systems may be effective at enriching soil organisms with little risk of weed infestation.     

长期有机–无机肥配施对农田杂草土壤种子库的影响

为揭示长期有机-无机肥配施处理下农田杂草土壤种子库的特征变化规律,本研究通过田间长期定位施肥模式试验,运用群落生态学方法研究了小麦-大豆轮作制度下大豆种植季7种施肥处理区杂草土壤种子库的结构及其生物多样性特征。结果表明,土壤样品中共检出杂草种子16种,隶属于10科; 土壤种子库总密度分布在15995~106300 grain/m2范围。长期有机-无机肥配施处理区的杂草土壤种子库优势物种组成较为简单,优势种为12种,配施麦秸处理区主要以栗米草为主,配施粪肥处理区主要以水苋菜为主; 土壤种子库的密度显著降低至15995~41900 grain/m2范围; 物种丰富度降低至7.67~9.33范围,并且将物种多样性和均匀度指数维持在休闲与纯化肥处理区之间（1.5~2.0和0.6~0.8）。长期配施麦秸、 粪肥均显著影响土壤杂草土壤种子库的结构特征,且麦秸与粪肥品种间差异的影响大于麦秸施用量差异的影响。因此,本研究认为有机-无机肥配施既有利于作物的优质高产,也可以通过调整有机肥种类以及与施用量来调控杂草土壤种子库,实现经济效益和生态效益的双赢。     

淹灌和间歇灌溉对晚稻田杂草群落多样性的影响

为探明节水灌溉对稻田杂草群落组成及物种多样性的影响,运用群落生态学方法,开展了淹灌与间歇灌溉2种灌溉模式下水稻不同生育阶段稻田杂草群落动态变化研究。结果表明:间歇灌溉和淹灌稻田杂草种类分别有10科13属14种、10科11属11种;间歇灌溉稻田各生育期杂草密度平均降低27.8%;优势杂草种类虽与淹灌基本一致,但阔叶类杂草矮慈姑重要值降低9.76%,单子叶杂草浮萍重要值降低65.38%;间歇灌溉稻田以旱生杂草生长为主,总体各生育期旱生杂草群落密度增加277.51%,水生杂草群落密度降低81.44%,而淹灌稻田以水生杂草为主;间歇灌溉稻田Margalef物种丰富度指数、Shannon-Wienner多样性指数、Simpson优势度指数和Pielou均匀度指数,平均提高27.01%、14.31%、9.09%和3.48%,乳熟期差异尤为显著。间歇灌溉提高了稻田杂草多样性,有效地抑制了优势种杂草生长,有利于改善稻田生态保护。该研究可为节水灌溉稻田杂草控制及多样性保护提供科学依据。