施肥对农田杂草生理生态及群落形成的影响综述

本文综述了施肥对农田杂草群落及土壤杂草种子库的影响,并探讨施肥可显著改变农田杂草发生的原因,论证合理的施肥能改善作物与杂草之间的关系,有效控制一些恶性杂草的发生,保持生物多样性。梳理了农田杂草研究的一些新的发展方向,并认为农业生态系统中施肥对杂草群落的演替、优势杂草种群的确定及其生理生态和遗传进化规律的影响是今后研究的重点和难点。     

害虫种群区域性生态调控的系统策略

害虫种群的区域性分布特征和生态调控已经成为近十年来综合治理研究的热点问题。经过几十年的发展,害虫生态调控的防控技术表现了可持续和绿色等特征,但从田块到区域尺度的生态调控系统策略还不完善,很多仍需依赖传统的化学防治为辅助。面对农业害虫区域性灾变的重大农业生态学问题,本文总结了害虫种群的区域性分布特征,包括区域性、异质性、扩散性、突发性、协同性五大特征;重点阐述了害虫种群区域性生态调控的系统策略,形成了预防性管理、靶向式调控、成灾后治理三位一体的害虫“防控治”生态调控体系,协调多种生态调控技术在区域水平内“防控治”才能有效遏制害虫种群的持续暴发;对害虫种群的区域性管理进行了展望,未来害虫种群的区域性生态调控不仅要考虑经济指标,还需要具备安全、高效、精准、可持续四大核心特点。因此,害虫种群的区域化生态调控是未来保障农业生产和生态安全的必然选择。     

冬小麦田间杂草小果亚麻荠为害研究与绿色防控

近年,黄土高原冬小麦田发现了一种新的农田杂草小果亚麻荠,其发生程度呈逐年上升趋势。调查其种群密度、麦田杂草群落演替变化发现,小果亚麻荠已经成为甘肃庆阳冬小麦田稳定的优势杂草种群,其在冬小麦田间发生的密度与种植新型油料作物荠蓝1号田块的距离有直接的相关性,与荠蓝1号地块距离越近,冬小麦田小果亚麻荠密度越大。此外,多年连作、采用深松或旋耕的冬小麦田以及上年种植小麦的冬油菜田,小果亚麻荠发生量较高。经试验,所采取的生态调控绿色措施防控效率达80%以上。     

模糊聚类分析在农田杂草群落分布和危害定量研究中的应用技术

本文介绍模糊聚类分析应用于农田杂草群落分布和危害研究中的技术。采用七级目测草害方法，调查获取杂草群落数量特征的资料，经综合值公式转化，进行模糊聚类分析。根据各样点的生态因子，选择截集水平，分出各别的聚类群。最后，用综合草害指数评价各聚类群的杂草种群危害值，明确各类型的优势杂草和种群，对农田杂草群落结构以定量分析，为杂草防除提供可靠依据。     

农田杂草种子库及其动态研究进展

农业的可持续性发展是我国农业发展的基本战略，它的发展离不开对农田草害的综合治理。农田杂草的发生、消长、演替与土壤杂草种子库的关系非常密切。在大多数情况下，影响杂草种群动态的主要因素是土壤杂草种子库的动态。研究土壤杂草种子的杂草种类组成、数量、分布及动态，对于研究杂草种群的消长规律、预测杂草群落的演替具有重要意义，可为持久稳定控制农田杂草发生与危害提供科学依据。本文综述了农田杂草种子库及其动态的国内外研究进展，详细分析了影响种子库动态的几种主要因素：农田的耕作方式、农作方式和除草力度等。     

关于将氮肥运筹技术纳入农田杂草综合防除体系的思考

我国是世界上化肥使用量最大的国家,面源污染和地力下降问题日益突出,为此农业农村部启动了"减肥减药"行动。杂草作为农田生态系统中除之不尽的植物,与作物存在复杂的竞争关系。前人研究结果表明,土壤养分状况影响作物和杂草间的竞争关系。那么,能否通过调节施肥量提高作物自身的竞争能力,从而降低杂草的危害,这为农田杂草的综合防控技术体系提供了新的思路和方法。因此,笔者建议以我国农田施用量最大的氮肥尿素和作物田优势杂草为研究对象,从植株构型和建成指标、氮代谢相关酶活性及其基因表达、同工酶谱的变化入手,从形态-养分-酶活性-基因4个层面系统阐述作物与杂草竞争关系响应氮素水平变化的生理与分子机理,以期为农田杂草综合防除体系中的氮肥运筹技术的形成提供理论依据。     

连云港地区麦田杂草防除

农田草害一直是影响连云港小麦产量的重要因素,虽然杂草综合治理已经取得了长足进步,但近年来麦田杂草的种群特点及种群数量都发生了一定变化。文章重点介绍了连云港地区旱茬和稻茬麦田的杂草发生规律、杂草类型以及针对旱茬、稻茬的不同特点采取不同的防除措施。     

潍坊市郊区玉米田杂草调查

近年来,随着农村种植业结构的调整、耕作制度的改变、大面积使用化学除草剂,农田杂草优势种群和群落结构,相应发生了变化。为了掌握我市农田杂草种群结构和发生危害情况,为今后草害治理提供依据,合理使用除草剂、及时控制其危害。作者于１９９８年７月至８月对所辖潍...     

农田生态经济除草阈值的调节

农田杂草生态经济除草阈值在实际应用中其合理性和准确性可受多种因素影响。本文就除草的生态效应、除草的非经济代价、社会经济水平、调查误差产生的决策风险以及作物品种、杂草种群、土壤肥力等多方面因素对生态经济除草阈值所产生的影响加以分析讨论,并引入调节因子α对阈值进行必要的调节,在上基础上制定了大豆男生态经济除草阈值ｑ２＝６４．７～１６．９,生态经济阈值ｑ１＝２１．１～９．１。     

农田杂草群落演替的影响因素综述

杂草是影响农业生产的重要生物逆境之一,农田杂草群落演替受到多种环境因素和人为因素的影响。本文概述了二氧化碳浓度升高、全球变暖、降水量变化等气候因素,保护性耕作、轮作、地膜覆盖、间作等耕作模式和种植制度,以及施肥、灌溉和化学除草剂的使用等农事操作,对农田杂草群落演替的影响,并对控制杂草群落演替,加强杂草防除进行了展望,提出了加强杂草危害监测预警、注重杂草防控技术研究、加强杂草抗药性监测和治理的建议。     

The role of arable weed seeds for agroecosystem functioning

A literature study was conducted to gather knowledge on the impact of weed seeds on agroecosystem functioning other than effects related to the production of weed seedlings and plants. The results of the review suggested that a larger and more diverse weed seedbank can contribute to the biodiversity of various groups of macrofauna and microbiota, with a positive or negative impact on the agroecosystem. However, relationships between weed seed availability and functional biodiversity in the field have generally not been established, with the exception of case studies of seeds sustaining populations of granivorous farmland birds or acting as reservoirs and vectors of plant pathogens. To value the contribution of different weed seeds to sustaining populations of functional biota, more detailed information on their relationships with seeds is essential. Hypotheses and related questions that can be used to explore the impact of weed seeds on functional biodiversity have been identified. The identification of weed seed species that are a key to sustaining functional biota may lead to a weed management strategy aiming to minimise the damage of weeds to crops while taking the alternative ecological roles of weed seeds into account.     

国内外有机果园杂草管理技术研究综述

在有机果园的日常管理中,应摈弃传统农业"根除杂草"的观念,建立"杂草管理"的可持续发展理念。杂草管理对建立和维持一个良好的有机果园尤为重要。本文主要围绕杂草对果园的影响以及如何有效地进行杂草管理展开综述,重点介绍了国内外有机果园普遍采用的杂草管理技术(包括耕作除草、果园覆草、生草覆盖、地膜覆盖、有机除草剂和火焰除草),旨在为有机果农实施杂草管理提供有益借鉴。     

发展化学除草重视综合治理

我国农田杂草有２５０多种，全国农田受草害面积４３００多万ｈｍ２，平均受草害减产１３．４％，每年减产粮食１７５０万ｔ，皮棉２５．５万ｔ和大豆５０万ｔ。传统农业生产采用机械作业及人力等除草。随着农村经济的发展，化学除草面积迅速扩大，全国农田化学除草面积从１９７５年的１７０万ｈｍ２增加到１９９５年的４１３３万ｈｍ２。但是，长期化学除草也带来了除草剂土壤残留对后茬作物药害、农田杂草种群更替和产生抗药性等新问题。必须重视农田杂草综合治理，通过采用各种有效的农业技术措施，为农作物保持良好的生态条件，结合化学除草才是最有效的防除杂草方法     

Managing arable weeds for biodiversity

As a result of the recent intensification of crop production, the abundance and diversity of UK arable weeds adapted to cultivated land have declined, with an associated reduction in farmland birds. A number of questions need to be addressed when considering how these declines can be reversed. Firstly, can the delivery of crop production and biodiversity be reconciled by spatially separating cropping from designated wildlife areas? A number of subsidised environmental schemes in the UK take this approach and are focused on establishing vegetation cover on uncropped land. However, because of the lack of regular disturbance in these habitats, they are dominated by perennials and they therefore have limited potential for promoting the recovery of annual weed populations. A number of farmland bird species also rely on the provision of resources in field centres, and it is therefore likely that the recovery of their populations will rely on weed management options targeted at the cropped areas of the field. This raises two further questions. Firstly, is it possible to identify beneficial weed species that are relatively poor competitors with the crop and also have biodiversity value? Secondly, are the tools available to manage these species at acceptable levels while controlling pernicious weeds? A number of approaches are being employed to answer these questions, including predicting yield loss from weed competition models and exploiting herbicide selectivity. The further development of these tools is crucial if farmer opposition to managing weeds in crops is to be overcome. Copyright © 2007 Society of Chemical Industry     

超高茬麦套稻田杂草发生特点、成因及化除策略

1998～2001年对江苏省5个不同生态区125个麦套稻田示范点的田间杂草发生情况进行了调查分析,初步掌握了麦套稻田杂草的发生特点,主要表现为种类多、发生早、群体大、危害重。免耕方式、前茬余草和前期田间管理粗放是造成杂草发生严重的原因。通过试验提出了"前封后杀"的化除策略,并研究出多项配套化学除草技术,促进了超高茬麦套稻田技术的大面积推广应用。     

Weeds in the traditional slash/mulch practice of frijol tapado: indigenous characterization and ecological implications

Weeds in the secondary vegetation of the fallow in slash/mulch or shifting cultivation systems have been identified as important components of the system. Weeds found in the traditional slash/mulch or frijol tapado bean (Phaseolus vulgaris L.) production system in southern Costa Rica were identified and given preliminary rankings based on fanner surveys. The variance of these rankings was used as a measure of farmer uncertainty. Weed rankings were further characterized by key informant interviews. This study also investigated the ecological implications of the vegetative dynamics in the system. Biomass estimates of individual weed species, nutrient dynamics and crop yield response are considered in conjunction with the farmers' rankings of weeds. A negative correlation was found between weed rankings and bean yield, and between weed rankings and C:N ratios.     

What criteria are relevant for predicting the invasive capacity of a new agricultural weed? The case of invasive American species in France

In Europe, exotic species are assessed for their potential threat only after they have already become weeds. To test hypotheses underlying risk assessment procedures, 274 North and South American exotic species naturalized in France were compared to differentiate environmental from agricultural weeds and to characterize weeds of several crops. Most agricultural exotic weeds belonged to the Asteraceae and the Poaceae, but proportionally to the total number of invasive species from a family the most successful families were the Amaranthaceae, Euphorbiaceae and Poaceae. Weed status in North and South America was the best predictor of agricultural weed status in France, and a pre-1900 date of introduction was associated with a greater likelihood of having become a major weed. The characteristics of 78 species present in field crops were examined in relation to management practices. In annual crops, the life-cycle compatibility of weeds appeared to be the main factor of selection. Exotic species differed in their C4 photosynthesis pathway in maize and rice. In vineyards, many ecological strategies are possible because the habitat is heterogeneous. Intrageneric comparison of exotic and native species showed a superior relative growth rate and higher biomass production under nutrient-rich conditions for exotics. However, it is still difficult to find a predictive function that fits well with all observed cases of weed invasion.     

不同轮作制度对定西地区农田杂草群落的影响

为探讨不同轮作制度对定西地区农田杂草群落的影响,采用倒置"W"九点取样法,调查了定西地区7种不同轮作制度下田间杂草的种类、数量、地上生物量等。在试验田发现11个科共15种杂草;从杂草发生密度、地上生物量上看,苦苣菜、藜是农田优势杂草,防除的目的杂草;不同轮作田的杂草群落由优势杂草组成;从不同轮作田杂草群落的物种多样性来看,马铃薯胡麻轮作马铃薯小麦轮作胡麻小麦轮作胡麻连作小麦胡麻轮作小麦马铃薯轮作胡麻马铃薯轮作;对不同轮作田杂草群落进行聚类,可分为四类。通过对不同轮作田中杂草的密度、地上生物量和综合优势度比的综合分析,可以看出胡麻连作、小麦胡麻轮作、马铃薯胡麻轮作、小麦马铃薯轮作中杂草的危害性较大。马铃薯小麦轮作、胡麻小麦轮作和胡麻马铃薯轮作对杂草有一定的控制作用。     

Weed seed germination and the light environment: Implications for weed management

Light regulates dormancy termination and the subsequent germination in many weed species. Under field conditions, the light environment of the seeds, which is perceived mainly by photoreceptors of the phytochrome family, provides essential information for cueing germination in the proper environmental situation. The light environment's spectral composition and irradiance allow weed seeds to sense their position in the soil profile, the presence of a leaf canopy capturing light and other resources and the occurrence of soil cultivation. From an agronomical point of view, the control of germination by light represents a potentially useful step in the life cycle of weeds for developing effective control practices. The goal of this article is to place current knowledge regarding photoreceptors, physiological and molecular bases of seed responses to light and their ecological implications within the context of weed management in agricultural systems. With that final objective, the authors intend to show how a better understanding of the way in which the light environment regulates dormancy termination and the subsequent germination of weed seeds could be used to develop more accurate control practices and to improve weed management strategies.