我国现代农业发展路线与发展战略

在当前,我国现代农业发展背负着重大包袱,面临着日益激烈的国际竞争,大力发展现代农业成为迫切需要.世界农业形势出现了新的变化,集中体现在理念创新、科技创新和制度创新.结合我围发展现代农业的国情,构建一个以产业理念创新为核心,以科技创新为动力,以组织保障制度创新为支撑的现代农业发展战略框架,描绘一个30年跨度的我国农业发展路线图,具有积极的理论意义与现实意义.     

硝化抑制剂硝基吡啶在农业和环境保护中的应用

讨论了硝化抑制剂硝基吡啶的作用机理,综述了硝基吡啶对农作物营养元素吸收、作物品质、作物产量、植物病害和毒害的影响,以及该硝化抑制剂对氮肥的淋溶损失和气态损失的影响.     

现代农业示范园区植物景观设计与配置意向--以衡阳市现代农业示范园核心区的园林绿化设计为例

衡阳是湖南省湘南地区最大的区域性城市,2003年衡阳市委市政府决定利用船山名人的旅游品牌效应和区位优势,在城郊衡阳县英陂镇境内建设集科研生产、农业示范、旅游观光于一体的现代农业示范园,实行资源和优势互补,为发展当地农村经济开辟新路子．衡阳市现代农业示范园的园林绿化建设应以景观生态学原理为指导,通过对示范园核心区的规划设计与构思、植物配置、管理措施与规划建设项目等方面的论述。以便为衡阳市委市政府发展观光旅游农业开发的决策和组织实施提供切实可行的理论依据．     

How well is farmers’ social situation captured by sustainability assessment tools? A Swedish case study

Recent research indicates that sustainability assessment tools (SAT) for farms need to be contextually adapted to be acceptable and useful. Focusing specifically on social sustainability, this study sought to identify important aspects of relevance for Swedish (livestock) farmers’ social situation and compare these aspects with social indicators used in three existing SATs (RISE, SAFA, IDEA). A survey revealed that social issues of key importance for the self-reported overall life satisfaction of Swedish livestock farmers are: having a good financial situation, having a similar standard of living as others, not experiencing too much stress, having meaningful work, having decent working hours, and having a desirable family situation. Of the three SATs evaluated, RISE appears best equipped to capture the social situation of Swedish farmers but does not fully address the aspect of finding work meaningful. SAFA and IDEA both fail to capture many aspects of importance for describing the social situation of Swedish farmers. We present a novel method for testing the relevance of social indicators for farmers in a specific context. Applying this method before choosing, applying, and adapting SATs for farm-level sustainability assessments would increase the relevance of the social sustainability dimension, but deeper stakeholder engagement than offered by our survey is needed.     

Effects of pollinator density-dependent preferences on field margin visitations in the midst of agricultural monocultures: A modelling approach

Managed field margins offer a means of reducing the impact of agricultural monocultures within intensively managed environments. By providing refuge for wild plants and the pollinators associated with them, field margins can also contribute to enhancing the pollination services within the monoculture. However, the effects of the monoculture on pollinator behaviour need to be carefully considered. It is known that pollinators may show density-dependent preferences such as neophobia (an avoidance of unfamiliar items) when different types of flower are available within their environment, and the dominance of monoculture crops within the environment may consequently have adverse effects upon the preferences shown by pollinators living in the field margins within them. In order to examine how pollinator preferences for wild flowers are affected by monocultures, we modelled the effects of density-dependent preferences, flower densities, and the geometry of field margins within a monoculture landscape using numerical simulations. This was done by considering how the placement of pollinator nests within a simple, spatially explicit landscape consisting of fields of monoculture crops separated by margins containing wild flowers affected the ratio of wild and monoculture crops experienced by the pollinator, given that it could only forage within a limited distance from its nest. Increasing field margin width and decreasing monoculture field width both led to an increase in pollinators visiting wild flowers (which levelled off as width increased). The size of the monoculture fields had little additional effect once they had passed an intermediate width. Increasing wild flower density within the margins led to a shift away from preferring monocultures. When wild flowers were at low densities compared to the monoculture, even the addition of small amounts of extra wild flowers had a large effect in shifting foraging preferences away from the monoculture. The distance which pollinators normally forage over only has an effect upon preferences for wild flowers when the travel distance is small. This suggests that careful consideration of margin design might be extremely important for those species which do not travel far. Innate preferences for density-dependence and particular crop types may also have an effect on preference behaviour. We demonstrate that the way in which resources are presented to indigenous pollinators may be extremely important in influencing where they choose to forage within agricultural landscapes. Careful margin design, as well as increasing the density of wild flowers (such as by enhancing the wild seed bank within the margins), may lead to overall improvements in ecosystem function within intensively farmed monocultures.     

Use of Stress‐Hormone Levels and Habitat Selection to Assess Functional Connectivity of a Landscape for an Amphibian

Abstract: The influence of landscape matrix on functional connectivity has been clearly established. Now methods to assess the effects of different land uses on species’ movements are needed because current methods are often biased. The use of physiological parameters as indicators of the level of resistance to animal movement associated with different land uses (i.e., matrix resistance) could provide estimates of energetic costs and risks to animals migrating through the matrix. To assess whether corticosterone levels indicate matrix resistance, we conducted experiments on substrate choice and measured levels of corticosterone before and after exposure of toads (Bufo bufo) to 3 common substrates (ploughed soil, meadow, and forest litter). We expected matrix resistance and hormone levels to increase from forest litter (habitat of the toad) to meadows to ploughed soil. Adult toads had higher corticosterone levels on ploughed soil than on forest litter or meadow substrates. Hormone levels did not differ between forest litter and meadow. Toads avoided moving onto ploughed soil. Corticosterone levels in juvenile toads were not related to substrate type; however, hormone levels decreased as humidity increased. Juveniles, unlike adults, did not avoid moving over ploughed soil. The difference in responses between adult and juvenile toads may have been due to differences in experimental design (for juveniles, entire body used to measure corticosterone concentration; for adults, saliva alone); differences in the scale of sensory perception of the substrate (juveniles are much smaller than adults); or differences in cognitive processes between adult and juvenile toads. Adults probably had experience with different substrate types, whereas juveniles first emerging from the water probably did not. As a consequence, arable lands could act as ecological traps for juvenile toads.