关于水资源管理的几个问题的探讨

水资源持续开发和永续利用是实现经济、社会和生态环境持续、协调发展的前提条件之一。加强水资源管理是实现水资源持续开发和永续利用的关键。本文认为要实现水资源的科学管理必须明确以下几个问题：水资源管理是以实现水资源的持续开发和永续利用为最终归宿；水资源管理应尽快完成由供给管理向需求管理的转变；明确水资源经济价值管理和环境价值管理方式的差异性；水资源管理应尽快上升为水资源资产化管理；我国干旱地区更要重视水资源的科学管理。     

Optimal pest management: A reproductive pollutant perspective

Abstract

Regarding pests as reproductive pollutants, pest management can be considered as an optimal stock management problem similar to that faced in fishery and forestry. Taking this view, an optimal control model with N heterogeneous farmers sharing a mobile pest is developed to investigate the conventional pest management tactic on a farm-by-farm basis and the innovative area-wide pest management tactic on a regional basis. The study results indicate that area-wide pest management (APM) is superior to farm-by-farm pest management in the presence of pest movement. We proceed to examine the stability of the cooperative solution under APM by formulating the pest management problem as a repeated game of infinite duration. The results suggest that a one-off pest suppression campaign can be a practical strategy for initiating APM programs.     

Our top 10 herbicide‐resistant weed management practices

Although proactive or reactive herbicide‐resistant weed management (HRWM) practices have been recommended to growers in different agroecoregions globally, there is a need to identify and prioritise those having the most impact in mitigating or managing herbicide selection pressure in the northern Great Plains of North America. Our perspective on this issue is based on collaborative research, extension activities and dialogue with growers or farming experience (cereal, oilseed and pulse crop production) during the past 30 years. We list our top 10 HRWM practices, concluding with the number 1 practice which is the foundation of the other nine practices: crop diversity. Although our top 10 HRWM practices have broad applicability across agroecoregions, their ranking may vary widely. © 2017 Society of Chemical Industry     

Integrated pest management and weed management in the United States and Canada

There is interest in more diverse weed management tactics because of evolved herbicide resistance in important weeds in many US and Canadian crop systems. While herbicide resistance in weeds is not new, the issue has become critical because of the adoption of simple, convenient and inexpensive crop systems based on genetically engineered glyphosate‐tolerant crop cultivars. Importantly, genetic engineering has not been a factor in rice and wheat, two globally important food crops. There are many tactics that help to mitigate herbicide resistance in weeds and should be widely adopted. Evolved herbicide resistance in key weeds has influenced a limited number of growers to include a more diverse suite of tactics to supplement existing herbicidal tactics. Most growers still emphasize herbicides, often to the exclusion of alternative tactics. Application of integrated pest management for weeds is better characterized as integrated weed management, and more typically integrated herbicide management. However, adoption of diverse weed management tactics is limited. Modifying herbicide use will not solve herbicide resistance in weeds, and the relief provided by different herbicide use practices is generally short‐lived at best. More diversity of tactics for weed management must be incorporated in crop systems. © 2014 Society of Chemical Industry     

Integrated weed management: Quo vadis?

The different components of Integrated Weed Management (IWM), such as crop selection, crop husbandry, plant nutrition, crop protection, farm hygiene, and the site-specific conditions, all are factors having an influence on the successful adoption of the basic IWM concept. Farmers' field activities, directly or indirectly, affect germination and development of weeds as well as weed population dynamics. However, also important non-agronomic parameters indirectly affect weed management. They include farm structure, farmers' personal targets and preferences, the provision and communication of technical know-how, economics, but also demands from society and in the area of ecology. In the light of the many additional important influences and interactions, rather than thinking in terms of IWM, it seems appropriate to view crop production as a whole process, probably best defined as Integrated Crop Management (ICM). Boiling down the mass of information and outlining a rational, straightforward, easy-to-apply and cheap approach for the site-specific weed management is needed for the successful implementation of IWM principles within the framework of ICM.     

Quality versus quantity: spring wheat seed size and seeding rate effects on Avena fatua interference, economic returns and economic thresholds

A 3-year field experiment was conducted at Kalispell, Montana, USA, to investigate the effects of spring wheat seed size and seeding rate on wheat yield loss (YL), economic returns and economic thresholds (ETs), as a function of Avena fatua density. Crop competitive ability increased as wheat seeding rate and seed size increased, with the greatest differences among treatment factors being observed at low weed densities. Both treatment factors decreased spring wheat YL, increasing economic returns during all 3 years of the study despite the higher associated seed costs. Averaged over all other factors, adjusted gross returns (AGR) were 477 and 537$ ha⁻¹ for the low and high seeding rates, while values of 453, 521 and 547$ ha⁻¹ were obtained for the small, bulk and large seed size classes respectively. Weed-free yield potential varied yearly. As yield potential increased, A. fatua competitive effects were more evident and ETs decreased. Nonetheless, both treatment factors increased ETs in 2 of 3 years. These results demonstrate that the use of higher seeding rates and larger seed size classes both improve wheat competitive ability towards A. fatua while simultaneously increasing economic returns.     

Effectiveness of fumigants and grafting against tomato brown root rot caused byColletotrichum coccodes

In an attempt to find effective control measures againstColletotrichum coccodes, an emerging pathogen causing root rot on tomato in northern Italy, four experimental trials were carried out during the years 2005 and 2006 in Piedmont and Liguria in order to evaluate the effectiveness of the combination of different rootstocks (Beaufort F1, He Man F1, Maxifort) with various fumigants. In the presence of medium to high disease incidence, the best results were obtained by combining the use of a resistant tomato rootstock with soil fumigation with dimethyl disulfide at 40 or 80 gm⁻² or metham sodium at 192 g m⁻². Chloropicrin, applied at 20 g m⁻², and the tested rootstocks alone, did not enable effective control of the pathogen. The need to monitor the appearance of new diseases and the resurgence of old ones is stressed.     

Evaluation of hydrophobic and hydrophilic kaolin particle films for peach crop, arthropod and disease management

Hydrophobic and/or hydrophilic kaolin particle film treatments to peach (Prunus persica (L) Batsch) trees were evaluated for crop and pest management capabilities in six studies from 1997 to 2000. Unsprayed control and standard treatments, the latter consisting of a commercial pesticide program, were included for comparison. Treatments in initial studies were applied via handgun, which resulted in a uniform and heavy deposit of kaolin after the first application. In contrast, treatments in subsequent studies used airblast equipment, which provided a uniform but less dense coverage, even after multiple applications. Results showed that both formulations of kaolin provided control of oriental fruit moth (Grapholita molesta (Busck)), plum curculio (Conotrachelus nenuphar (Herbst)) and Japanese beetle (Popillia japonica Newman) that was comparable with or better than the standard pesticide program. Effective management of late season catfacing insects (tarnished plant bugs Lygus lineolaris (Palisot de Beauvois) and stinkbugs Acrosternum hilare (Say), Euschistus servus (Say), and E tristigmus (Say)) and leafrollers (undetermined species) was also observed, although kaolin applications significantly increased phytophagous mite (Panonychus ulmi (Koch)) levels. In contrast to arthropod management, kaolin failed to control either peach scab (Cladosporium carpophilum (Von Thumen)) or rusty spot (Podosphaera leucotricha (Ell and Ev) ES Salmon) in any of the 4 years of the study. However, hydrophobic kaolin provided effective brown rot (Monilinia fructicola (G Winter) Honey) control when applied via handgun, and partial control when applied via airblast; hydrophilic kaolin failed to provide any control. These results suggest that hydrophobicity and deposit density may be important factors for effective disease management. The application of kaolin significantly delayed fruit maturation, increased fruit size and increased soluble solids relative to the standard. This effect, attributed to a reduction in plant stress, also resulted in increased fruit number and yield on young trees, indicating that an accentuated beneficial response from kaolin applications may be possible.     

Herbicide‐resistant weed management: focus on glyphosate

This review focuses on proactive and reactive management of glyphosate‐resistant (GR) weeds. Glyphosate resistance in weeds has evolved under recurrent glyphosate usage, with little or no diversity in weed management practices. The main herbicide strategy for proactively or reactively managing GR weeds is to supplement glyphosate with herbicides of alternative modes of action and with soil‐residual activity. These herbicides can be applied in sequences or mixtures. Proactive or reactive GR weed management can be aided by crop cultivars with alternative single or stacked herbicide‐resistance traits, which will become increasingly available to growers in the future. Many growers with GR weeds continue to use glyphosate because of its economical broad‐spectrum weed control. Government farm policies, pesticide regulatory policies and industry actions should encourage growers to adopt a more proactive approach to GR weed management by providing the best information and training on management practices, information on the benefits of proactive management and voluntary incentives, as appropriate. Results from recent surveys in the United States indicate that such a change in grower attitudes may be occurring because of enhanced awareness of the benefits of proactive management and the relative cost of the reactive management of GR weeds. Copyright © 2011 Society of Chemical Industry     

澳大利亚农药管理现状经验与思考

本文主要阐述澳大利亚在农药管理现状,通过详细分析澳大利亚农药管理模式,提出可供我国农药管理工作思考、借鉴的意见、建议。     

我国农药质量监测体系建设的现状及展望

农药作为重要的农用生产资料,其质量的好坏直接影响着农业生产,但我国农药质量监督检测体系发展滞后,存在许多问题,影响了我国农药质量的提高。本文重点阐述了我国农药质量监测体系的现状、存在问题并对未来发展作出了展望。     

小麦主要害虫的发生动态及可持续控制的策略与实践

简要分析中国近10年来小麦主要害虫的发生为害动态,重点综述了国内小麦主要害虫综合防治策略的发展、实施可持续控制技术攻关的研究思路和重要进展,探讨了小麦害虫防治技术需进一步改进和提高的有关问题。     

资源型小城市的垃圾分类收集与管理模式的探讨

针对资源型城市的特殊性,以阜新为例,分析我国资源型小城市的垃圾处理和管理体制的现状,提出适合资源型城镇的垃圾收集方式并结合原有垃圾管理体制根据垃圾综合管理的原理,以垃圾减量化、资源化、无害化、产业化为目标,在环境可持续性、经济可负担性、社会可接受性的基础上构建适合于资源型小城市的垃圾管理新体制。     

The integrated control concept and its relevance to current integrated pest management in California fresh market grapes

The foundation of an integrated pest management program involves valid treatment thresholds, accurate and simple monitoring methods, effective natural controls, selective pesticides and trained individuals who can implement the concept. The Integrated Control Concept written by Stern, Smith, van den Bosch and Hagen elucidated each of these points in an alfalfa ecosystem. Alfalfa hay (Medicago sativa L.) has a low per acre value, requires little hand labor and is primarily marketed in the USA. In contrast, fresh market table grape (Vitis vinifera L.) has a high per acre value, requires frequent hand labor operations, suffers unacceptable cosmetic damage and is marketed throughout both the USA and the world. Each of the components of a working IPM program is present in table grape production. Marketing grapes to foreign countries presents special problems with pests considered invasive and where residue tolerances for some selective insecticides are lacking. However, fresh market grape farmers are still able to deal with these special problems and utilize an IPM program that has resulted in a 42% reduction in broad‐spectrum insecticide use from 1995 to 2007. Copyright © 2009 Society of Chemical Industry     

Can an integrated management approach provide a basis for long-term prevention of weed dominance in Australian pasture systems?

Broad-leaved weeds in pasture, such as Carduus nutans, Onopordum spp. and Echium plantagineum are a major problem for graziers in southern Australia. Previous attempts to combat these weeds with a single technique have only resulted in short-term success. An approach to long-term control, combining biological control with different grazing and herbicide strategies, was evaluated in an integrated weed management (IWM) programme, in south-eastern Australia. This IWM study was one of the few that has focused on biological control agents. During the field trials, the impacts of grazing and herbicide treatments on the weed and biological control agents, as well as on pasture composition, were monitored. This paper concentrates on the part of the study that focuses on the role and importance of pasture composition as part of weed management. The main pasture components were monitored using botanal , a sampling technique for estimating species composition and pasture yield in the field. IWM is a long-term ecological approach and after 3 years, major trends were just becoming apparent. This study shows that pasture composition can be manipulated to increase productivity and sustainability. It demonstrates that broad-leaved weeds can be reduced when high level pasture background management and chemical control are combined.     

Impact of cropping systems on the weed seed banks in the northern Great Plains, USA

Very little research has been done on weed seedbank communities in the northern Great Plains region of the USA. The objectives of this study were to evaluate the effects of management systems on the weed seed banks and to assess the relationship between the weed seed banks and the above-ground weed communities. The seed banks were sampled along a range of areas of above-ground weed diversity in organic and conventional spring wheat production fields near Big Sandy, Montana, over 2 years. Eight 1 m × 0.33 m areas were selected in each field to encompass a wide range of above-ground weed diversity and soil cores were taken in each area to a depth of 20 cm and split in half at 10 cm. The number of seeds recovered from the top 10 cm of soil and the 10–20 cm depth were significantly affected by the sampling year and an interaction between the cropping system and the sampling year. The year was the only significant predictor affecting the weed seedbank diversity at both depths. A significant interaction between the management system and the year observed at the 10–20 cm sampling depth reflected the higher rate of decrease in diversity occurring between 2005 and 2006 in the conventionally managed fields compared with the organic fields. A multivariate ordination indicated that, although the year played a significant role in determining the weed seedbank communities, the management system had a role only during 2006. We failed to detect strong correlations between the above-ground and underground weed communities. The results of this study suggest that, in the studied region, yearly fluctuations in environmental factors have significant impacts on the weed seed banks.     

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。     

Tillage and nitrogen management effects with sequential and ready-mix herbicides on weed diversity and wheat productivity

In this experiment, weed management was studied in zero tillage (ZT) and conventional tillage (CT) wheat with and without crop residue and nitrogen (N). The treatment ZT with crop residue retention (R) and 75% of required N plus GreenSeeker? (GS)-aided N management (ZTRNGS) resulted in a reduction of density and dry weight of weeds compared to CT and ZT without residue. Sequential application of pendimethalin and sulfosulfuron (PMT-SSF) reduced the weed density and dry weight compared to the weedy check (WC). Importantly, the richness and diversity indices were high in ZTRNGS and in WC treatments. Greater wheat grain (5.11 t/ha) and biomass yield (13.31 t/ha) were observed in ZTRNGS than CT without residue and blanket split application of N (CTN). The treatment ZTRNGS recorded 14.1% and 16.9% higher gross and net returns, respectively, over CTN. This study demonstrates that surface retention of crop residue in ZT is more useful than residue incorporation under CT for effective weed control, improving crop yield and profitability.