巴西农业生产与科研推广体系

文章简要介绍了巴西农业生产概况、农业科研体系和农业技术推广体系。     

作物栽培与耕作学科发展

近60年来中国作物栽培与耕作学在理论建设、技术创新和技术体系构建等方面取得了显著成效,围绕作物高产、优质、高效、生态、安全生产需求,在作物生育调控理论及技术途径上不断取得突破,在多熟种植、作物布局和种植模式优化上不断创新发展,并通过技术集成应用有效支撑中国粮、棉、油等农产品生产能力稳步提升。面对当前及未来中国农业转型发展的战略需求,如何将资源高效、环境安全与作物高产高效并重,构建用养结合、生态高效、生产力和竞争力持续提升的作物生产体系,是作物栽培与栽培学科创新发展的总体目标和艰巨任务。     

不同放牧制度对高原鼢鼠活动区高寒草地群落结构影响

为探讨不同放牧制度对高原鼢鼠的生物调控机制,本研究以高原鼢鼠（Myospalax baileyi）危害严重的天然草场为研究对象,通过网围栏设置禁牧区、季节性放牧区及自由放牧区,分析草地群落结构及高原鼢鼠种群密度与单子叶、阔叶类植物的相关性。结果表明：禁牧区禾本科植物重要值两年均高于季节性放牧和自由放牧区。3个样区的多样性指数在第二年都有所增加;同时,自由放牧区第一年的优势度指数和均匀度指数高于季节放牧区和禁牧区;季节性放牧第二年草地群落多样性指数高于禁牧区和自由放牧区,同时季节性放牧区的优势度指数显著高于禁牧区和自由放牧区（P<0.05）。另外,禁牧区单子叶植物地上生物量最高,季节放牧区阔叶类植物地下生物量最高。高原鼢鼠相对鼠群密度表现为：季节性放牧区>自由放牧区>禁牧区,且禁牧区高原鼢鼠相对种群密度与单子叶植物地上生物量、阔叶类植物地下生物量呈正相关;季节性放牧区的相对鼠群密度与地上生物量呈负相关,与地下生物量呈正相关;自由放牧区的相对鼠群密度与单子叶植物地上生物量呈负相关,与单子叶植物地下生物量、阔叶类植物生物量（地下、地上）均呈正相关。综上所述,建立合理的放牧制度可以改善高寒草甸草地群落结构,进而调控高原鼢鼠的种群密度。     

社会转型期档案工作的新思路——论档案工作“两个体系”建设的理论内涵、时代意义和实现途径

实现“两个转变”、建立“两个体系”是新时期我国档案工作的新战略,现从理论内涵、时代意义和实现途径等方面对其进行全方位分析,探讨不同实践主体在建立“两个体系”中的职责和任务,为促进“两个体系”建设目标的实现提供参考。     

Pre-harvest survival of codling moth in artificially infested sweet cherry fruits

Prior to the 2009 season, sweet cherry fruits, Prunus avium (L.) L., from North America were required to be fumigated with methyl bromide before being exported to Japan to eliminate possible infestation by codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae). However, based on recent biological research on host status, a new procedure (the “systems approach”) was implemented relying on the cumulative effects of pre- and post-harvest practices to produce pest-free sweet cherry fruits for export. This is an organized process that involves the integration of procedures used in the production, harvest, packaging, and distribution of a commodity which cumulatively meet the requirements for quarantine security. The objective of our study was to provide additional information to support the systems approach for codling moth in sweet cherries fruits. For four seasons, branches with sweet cherry fruits were caged on trees and infested by released ovipositing codling moths into the cages. Fruits were sampled weekly for codling moth individuals at each life stage. Eggs were laid mostly on leaves with the seasonal average numbers per cage ranging from 142 to 617. Populations declined rapidly after egg eclosion, with <1.5% of the original cohort surviving to fifth instars. Even after 8 weeks, none had formed cocoons or pupated. This failure of the codling moth to complete a life cycle under field conditions supports previous life history studies and demonstrates that sweet cherry fruits are inadequate hosts for codling moth.     

基于项目的Java课程综合实训设计

本文介绍了医院管理软件要实现的功能及对系统进行的总体设计、系统功能模块设计及数据库设计,描述软件设计过程中的主要技术细节。     

建设内蒙古河套平原生态农业“六三系统工程”研究

针对影响建设内蒙古河套平原生态农业存在的土壤盐渍化、风沙化和地力退化三大生态制约因素,研究设计编制了“六三系统工程”为防治对策的宏观调控运行管理模式,阐述了此项自然科学与社会科学综合研究的重要进展。     

Water resources and water use efficiency in the North China Plain: Current status and agronomic management options

Serious water deficits and deteriorating environmental quality are threatening agricultural sustainability in the North China Plain (NCP). This paper addresses spatial and temporal availability of water resources in the NCP, identifies the effects of soil management, irrigation timing and amounts, and crop genetic improvement on water use efficiency (WUE), and then discusses knowledge gaps and research priorities to further improve WUE. Enhanced irrigation and soil nutrient (mainly nitrogen) management are the focal issues in the NCP for enhancing WUE, which are shown to increase WUE by 10-25% in a wheat-maize double cropping system. Crop breeding has also contributed to increased of WUE and is expected to play an important role in the future as genetic and environmental interactions are understood better. Agricultural system models and remote sensing have been used to evaluate and improve current agronomic management practices for increasing WUE at field and regional scales. The low WUE in farmer's fields compared with well-managed experimental sites indicates that more efforts are needed to transfer water-saving technologies to the farmers. We also identified several knowledge gaps for further increasing WUE in the NCP by: (1) increasing scientific understanding of the effects of agronomic management on WUE across various soil and climate conditions; (2) quantifying the interaction between soil water and nitrogen in water-limited agriculture for improving both water and nitrogen-use efficiency; (3) improving irrigation practices (timing and amounts) based on real-time monitoring of water status in soil-crop systems; and (4) maximizing regional WUE by managing water resources and allocation at regional scales.     

北京市蛋鸡繁育体系最优结构的研究

利用系统分析的方法,根据线性规划模型预测了北京市未来蛋鸡良种繁育体系的最优结构,以充分利用现有的饲料资源、生产资金和鸡舍条件,使经济效益达到最大。同时还进行了灵敏度分析,对最优结构的可行性和几种配套利用形式进行了讨论,为北京市蛋鸡生产的规划和决策提供了科学依据。     

重要农业文化遗产及其保护研究的优先领域、问题与对策

重要农业文化遗产是指在经济、生态、技术、文化与景观等方面具有显著特征,并在农业与农村历史演进与可持续发展中具有重要价值的传统农业生产系统,包括联合国粮农组织(FAO)认定的全球重要农业文化遗产(GIAHS)和中国农业农村部认定的中国重要农业文化遗产(China-NIAHS)。截至2020年6月底, FAO已经认定了62个项目,分布在22个国家;农业农村部已经发布了5批118个项目,分布在28个省、自治区、直辖市。与此同时,重要农业文化遗产及其保护也引起了越来越多不同专业领域的学者们的关注,并对重要农业文化遗产的概念与内涵、特征与价值、申报与管理、保护与发展等方面开展了研究,逐步形成了一个具有显著交叉特征的新的学科领域。本文从重要农业文化遗产的概念、内涵与特点出发,提出当前重要农业文化遗产研究的12个优先领域;从重要农业文化遗产保护工作需求出发,提出重要农业文化遗产保护研究的20个优先领域。结合过去15年来从事重要农业文化遗产及其保护研究与实践的体会,分析了当前研究中存在的3个主要问题,并提出了相应对策。