甲维盐对锯谷盗成虫的控制作用研究

试验室内测定了甲维盐对主要储粮害虫锯谷盗成虫的触杀作用和种群抑制作用.当浓度为16 μg/cm2,作用时间48h时,甲维盐对锯谷盗成虫的触杀死亡率达100％.甲维盐对锯谷盗的LD5o值为0.6780,毒力回归方程为y=5.6166＋3.6537x.同时,当处理剂量为1mg/kg时,甲维盐对锯谷盗成虫当代和子代种群抑制率均为100％.结果表明,甲维盐对锯谷盗具有很强的触杀作用和胃毒作用.     

硝酸分解磷矿粉生产硝基节酸磷肥

在硫资源缺乏且需要硝态氮的作物区,可以适当的发展硝基节酸磷肥。硝态氮能直接被作物吸收,属于速效性肥料,可用作追肥或寒冷季节作物施肥。不含重金属离子的废酸与磷矿粉混合后,作为硝基磷肥,既解决了废酸处理问题,又同时副产肥料。采用不足量的硝酸来分解磷矿,生产硝基节酸磷肥,综合分析,较佳的反应条件为磷矿粉与折纯硝酸质量比为1.0～1.2,烘干固化温度120℃左右,烘干固化时间8h。该方法处理后,矿粉分解率74.41%,所得硝基磷肥总养分为25.09%,其中有效磷17.55%,硝态氮7.54%。     

新型肥料的最新开发进展及应用

现代农业正在促使化肥品种结构发生变革,产生质的飞跃,近年来各种新型肥料不断问世。新型肥料的主要作用是能够直接或间接地为作物提供必需的营养成分,调节土壤酸碱度,改良土壤结构,改善土壤理化性质和生物学性质,调节或改善作物的生长机制,改善肥料品质和性质及提高肥料的利用率。21世纪以后,中国新型肥料研发和推广使用正快速发展,肥料结构不断优化,新型肥料更是异军突起。介绍了近期中国最新创制的活化磷肥、有机钾肥、氨酸螯合肥、含肽氮肥、硫磺加强型肥料、富过磷酸钙磷肥、生物有机肥、高分子聚合物增效肥料等8种新型肥料的开发进展和应用概况。．     

微生物对水田化肥氮素利用率的影响

通过改进施肥方法和施用微生物肥料,探讨对稻田土壤微生态环境及氮素转化动态的影响。结果表明,施用微生物肥料后,水稻根际微生态环境得到明显改善;提高水稻植株对化肥氮素的吸收量,增加土壤氮的残留,减少氮肥的挥发损失及反硝化作用。同时肥料深施也能大大减少氮素的损失,增加根际微生物数量,从而提高作物产量。     

Is Site-Specific Yield Response Consistent over Time? Does It Pay?

This study examines the profitability and stability of site-specific (SS) nitrogen fertilizer recommendations using an empirical model of SS yield response to controlled inputs, stable site characteristics, and time-varying weather factors. Using a three-year panel of on-farm corn yield experiments and new, continuous variables to describe site characteristics, both spatial and ordinary least squares regression models show clear evidence of SS corn yield response to nitrogen fertilizer. Yield response is predictable only on irrigated fields. Even there, bootstrapped confidence intervals for profitability gains on selected fields indicate that SS nitrogen application would rarely cover its costs.     

The Economics of Controlling Insect-Transmitted Plant Diseases

A framework is developed to analyze a spatially dependent economically significant pest problem emanating from a source and spreading via a carrier such as an insect. Transmission and/or source control to combat the pest or disease problem are explored. Alternative assumptions about the effectiveness of transmission control and the feasibility and costs, both social and private, of reduction of the pest population at the source are examined in an application of the model to controlling Pierce's disease in California wine grapes.     

电子商务中的生物识别技术及其发展

随着信息技术与信息化建设的发展,基于Internet的电子商务正在以前所未有的速度迅猛发展。生物识别技术作为一个电子商务中独特的领域越来越受到关注。认证技术是电子商务安全的关键。因此,只有深入了解电子商务中的生物识别技术的特点、内容以及发展,才能更好地完善电子商务中的安全技术,使电子商务发挥更大的作用。     

化肥的生产和使用中存在的问题与建议

本文分析了我国化肥生产存在的各种问题，解剖了存在问题的根源，并对如何解决这些问题提出了合理化的建议。     

微生物菌肥在农业生产中的价值和应用

文章简要介绍微生物菌肥的概念、作用机理、作用,关注其在农业生产过程中的实际应用情况。同时,以此为前提,为微生物菌肥指明未来的应用路径。     

Soil biota, ecosystem services and land productivity

The soil environment is likely the most complex biological community. Soil organisms are extremely diverse and contribute to a wide range of ecosystem services that are essential to the sustainable function of natural and managed ecosystems. The soil organism community can have direct and indirect impacts on land productivity. Direct impacts are those where specific organisms affect crop yield immediately. Indirect effects include those provided by soil organisms participating in carbon and nutrient cycles, soil structure modification and food web interactions that generate ecosystem services that ultimately affect productivity. Recognizing the great biological and functional diversity in the soil and the complexity of ecological interactions it becomes necessary to focus in this paper on soil biota that have a strong linkage to functions which underpin ‘soil based’ ecosystem services. Selected organisms from different functional groups (i.e. microsymbionts, decomposers, elemental transformers, soil ecosystem engineers, soil-borne pest and diseases, and microregulators) are used to illustrate the linkages of soil biota and ecosystem services essential to life on earth as well as with those associated with the provision of goods and the regulation of ecosystem processes. These services are not only essential to ecosystem function but also a critical resource for the sustainable management of agricultural ecosystems. Research opportunities and gaps related to methodological, experimental and conceptual approaches that may be helpful to address the challenge of linking soil biodiversity and function to the provision of ecosystem services and land productivity are discussed. These include: 1) integration of spatial variability research in soil ecology and a focus on ‘hot spots’ of biological activity, 2) using a selective functional group approach to study soil biota and function, 3) combining new and existing methodological approaches that link selected soil organisms, the temporal and spatial dynamics of their function, and their contribution to the provision of selected ‘soil based' ecosystem services, 4) using understanding about hierarchical relationships to manage soil biota and function in cropping systems, 5) using local knowledge about plants as indicators of soil quality, remote sensing and GIS technologies, and plant-soil biota interactions to help understand the impacts of soil biota at landscape scale, and 6) developing land quality monitoring systems that inform land users about their land's ecosystem service performance, improve capacities to predict and adapt to environmental changes, and support policy and decision-making.