21世纪农业及农业工程科学技术发展的趋势、特点

基于分析２０世纪后期,世界农业发生的重大变化及由此引起的全球环境恶化等问题,本文着重论述了２1世纪农业及农业工程科学技术发展的趋势与特点。说明持续农业是世界农业发展的总趋势。依照世界农业、农业工程科学技术发展的态势,根据我国的国情及适合我国国情的现代化农业发展道路,阐述了我国农业及农业工程科学技术发展的目标与方向。     

Seasonal migration and land‐use change in Ghana

When farmers migrate yearly to a village to carry out intense farming during the rainy season, and thereafter return to a more permanent place of abode this is referred to as seasonal migration. The impact of such migration on land‐use/land‐cover change in an area within the Volta Basin of Ghana was examined using satellite image analysis and socioeconomic surveys. The most drastic land‐cover change involved the conversion of woodland to agricultural land, while there was also a general transition to less vegetation cover. Socioeconomic surveys revealed that most of the migration occurred during the post‐structural adjustment period in Ghana with declining soil fertility accounting for the highest per cent of causes of migration. Multiple regression results highlighted the role of population size and distribution, marketing of agricultural produce and technological evolution of the household in determining agricultural land‐use change. Policy initiatives that could lead to environment conservation are suggested. Copyright © 2004 John Wiley & Sons, Ltd.     

中国土壤学过去30年在一些关键领域的研究进展

Due to continuous decreases in arable land area and continuous population increases,Chinese soil scientists face great challenges in meeting food demands,mitigating adverse environmental impacts,and sustaining or enhancing soil productivity under intensive agriculture.With the aim of promoting the application of soil science knowledge,this paper reviews the achievements of Chinese scientists in soil resource use and management,soil fertility,global change mitigation and soil biology over the last 30 years.During this period,soil resource science has provided essential support for the use and exploitation of Chinese soil resources,and has itself developed through introduction of new theories such as Soil Taxonomy and new technologies such as remote sensing.Soil fertility science has contributed to the alleviation and elimination of impeding physical and chemical factors that constrain availability of essential nutrients and water in soils,the understanding of nutrient cycling in agroecosystems,and the increase in nutrient use efficiency for sustainable crop production.Chinese soil scientists have contributed to the understanding of the cropland’s role in global change,particularly to the understanding of methane and nitrous oxide emission from rice fields and the effect of elevated carbon dioxide and ozone on rice-wheat system.Soil biology research has progressed in biological N fixation,distribution of fauna in Chinese soils,and bioremediation of polluted soils.A new generation of soil scientists has arisen in the last three decades.The gaps between research and application in these soil science fields are also discussed.     

贮备饲料近红外光谱模型快速预测青绿饲料营养成分含量

为快速检测饲料的营养成分,该研究利用贮备饲料的近红处技术(near-infrared,NIR)快速分析模型预测青绿饲料的营养成分含量。基于贮备饲料的NIR定标模型,将建模优化模式转移应用到青绿饲料的营养成分定量检测,以判断模型转移能力。在实验室环境下扫描并记录新鲜的青绿饲料样本和储存的贮备饲料样本的近红外反射光谱,利用230个贮备饲料样本进行光谱定标训练,以修正偏最小二乘(modified-partial least squares,M-PLS)建模方法,结合随机局部样本、局部选参、局部非连续性可调、交叉检验等技术相结合的方式建立局部优化模型,分别测试120个贮备饲料样本和120个青绿饲料样本中的氮(nitrogen,N)、中性洗涤纤维(neutral detergent fiber,NDF)、酸性洗涤纤维(acid detergent fiber,ADF)含量。将贮备饲料的定标校正模型应用于贮备饲料验证样本的营养成分测定,其标准误差(square error of prediction,SEP):N为1.02、NDF为16.56和ADF为13.47,相关系数均在0.9以上,相对预测偏差(relative prediction derivation,RPD)均大于3;该模型具有对青绿饲料样本的营养成分预测能力,其预测SEP:N为0.90、NDF为14.11和ADF为9.98,预测相关系数均在0.9以上,预测RPD均大于3,达到快速检测误差标准。由于局部建模过程中考虑了数据的潜在非线性结构和具有近似光谱响应的样本之间的不均匀性,相对全局建模方式而言具有更好的数据驱动性质,其建模效果优于全局建模方法。结果表明,基于贮备饲料样本建立的NIR定标校正模型可以用于青绿饲料营养成分的预测,特别是局部分析模型的应用能够提高NIR快速分析的预测精度。     

气候变化背景下农田土壤碳储量评估方法研究进展

气候变化对自然和社会生态系统产生了深远影响。农田土壤碳储量作为陆地碳库的重要组成部分,不仅影响全球气候变化,也关系到农业可持续发展和全球粮食安全。通过梳理相关文献,探讨气候变化对农田土壤碳储量的影响,探究农田土壤碳储量评估方法的优缺点及其适用性。论文总结了气候变化单因子（气温升高、降水模式变化、二氧化碳浓度升高、大气氮沉降和各种极端天气事件）及其多因子联合（温度-降水、温度-降水-二氧化碳和二氧化碳-氮沉降-臭氧）对农田土壤碳储量的影响,分析了包括统计分析方法、基于机理的过程模拟模型方法和组合模型方法的农田土壤碳储量评估方法优缺点。最后,从关注微生物介导的土壤碳储存机制、聚焦气候变化多因子交互效应、发展综合模拟模型、模型不确定性研究4个方面提出了未来研究方向。     

基于Fisher判别法则的小麦品质多指标分级

小麦生理生化指标对研究其储藏品质具有重要的作用,但由于各指标间关系的复杂性,所表达的信息存在较大差别,这给小麦储藏品质分析带来很大的不便。针对该问题,该文提出了一种小麦储藏品质多指标分析模型,选取降落数值、发芽率、过氧化物酶、脂肪酸值、电导率、还原糖值、丙二醛7个生理生化指标作为分析的关键因素,通过相似性和主成分法对各指标进行分析计算,发现脂肪酸值最具代表性;基于脂肪酸值数据分布变化趋势,采用聚类分析方法对小麦分类;使用Fisher判别法对小麦数据进行训练,得到2类判别函数,其中判别函数1的贡献率达到89.7%,在该函数下,计算获得3种类别小麦的中心值为–5.699、1.316和3.945,从而为判断小麦的品质状况提供计算依据。试验计算结果表明,在18批储藏小麦中,该文判别模型对小麦的分类结果与实际参考标准分类结果的一致性达到88.9%,验证了本模型的合理性,研究结果可为小麦品质评价分类提供参考。     

Can conversion to organic farming restore the species composition of arable weed communities?

Benefits of organic cropping for biodiversity have usually been demonstrated in relation to modern conventional cropping. In this study, the ability of organic cropping to restore species composition of weed communities was explored by comparing weed communities of present day organic cropping with weed communities at the beginning of the application of modern cropping measures in the 1960s. The data of two weed surveys of spring cereals (conducted in 1961-1964 and 1997-1999) in Finland were utilized for a comparison. Frequency of occurrence and density (plants m⁻²) of 41 weed species were compared between decades. Partial canonical correspondence analysis (pCCA) was applied to explore the relationship between species composition, management and non-management variables. Eight species had lower and 30 species higher or similar frequency of occurrence in the 1990s’ organically cropped fields than in the fields of the 1960s. However, 18 species had lower and 20 species had higher or similar density in the organically cropped fields than in the fields of the 1960s. Three species were not detected at all in the organically cropped fields. Crop and under-sown grass explained more of the variation in species composition in the 1990s than in the 1960s. The role of drainage and pre-crop was more important in the 1960s than in the 1990s. The most immediate benefit was gained by nitrophilous species that had suffered from herbicide application. The recovery of perennials and non-nitrophilous species will take a longer time. The results suggest that despite some benefits for biodiversity, organic farming at early phase cannot recover weed populations to the same level as before application of intensive cropping measures.     

基于ARIS的农业信息采集平台需求分析方法

需求分析是信息系统工程的关键,随着农业信息化的发展,农业信息系统工程的需求定义和分析也逐渐得到重视。该文针对农业软件系统研制中经常发生的需求无法得到准确描述的问题,在农业信息采集平台的研制过程中引入ARIS需求分析建模方法。通过对农业信息采集平台的需求建模,研究了ARIS 5种视图在农业信息系统建模中的应用,采用EPC建立流程模型。最后结合软件研制实例分析了ARIS需求分析建模方法在农业领域应用软件研制中的优势。     

信息技术提升农业机械化水平

为适应中国现代农业建设的需要,保持中国农业机械化水平持续增长,实现中国农业可持续发展,该文提出,应将先进的信息技术融入中国农业机械的设计、制造、作业和管理等环节,使农业机械装备实现信息化和智能化,从而整体提升农业机械化水平。文中介绍了参数化设计、基于知识工程的农机产品设计、基于产品数据管理的并行协同设计等农机产品设计的关键技术;柔性制造、计算机集成制造、虚拟与网络制造等农机产品制造的关键技术;农情信息采集、农业机械导航、田间管理等农业机械作业的关键技术;农业机械管理、农业机械调度等关键技术。分析了这些关键技术信息化的不足,总结了世界各国的发展趋势,指出了用信息技术提升中国农业机械化水平应解决的核心问题。为加强农机装备的信息技术创新,该文建议,应突破一批智能农业装备数字化设计技术、自动导航协调控制技术及农业装备现场总线技术等关键技术;研发一批大田和设施农业生产作业系统、果园作业智能装备和畜禽水产精准生产装备等重大技术产品;构建一批水肥药田间精准作业系统、畜禽水产自动饲喂系统和自动化加工生产线等农业机械精准作业系统,从而进一步用信息技术提升农业机械化水平。     

农田生态系统分析与农业可持续发展

农田生态系统分析是以农民为中心,由自然科学工作者、社会科学工作者、决策管理人员、土地规划人员和农民共同参与,通过研究农民实际生存的农业自然环境、社会、文化、经济环境,结合考虑农民的意愿与抉择,提出解决农田生态系统问题的一种动态过程与方法,其基本目标是实现中小尺度上的农业可持续发展。农田生态系统分析一般包括５个阶段：问题诊断与分析、研究方案设计与规划、方案验证与评价、结果评价阶段和建议与推广应用。据此,提出适宜于不同农业生态系统的可持续发展方案,为区域乃至国家范围的可持续发展提供决策依据。该文分析了农田生态系统分析的概念、起源、目标、特征和研究过程。     

台湾生态工程材料之应用与评估

 对目前台湾地区所使用生态工程施作地点及应用材料等进行调查汇整、研究及分析,并就符合多样性生物栖息环境之生态工程材料进行开发研究,包括现地调查,岛内外资料搜集与资料分类整理,将已汇整的材料表格化。材料组件分为生物材料与非生物材料,而工法组合材料则分为木材工法类、地工材料类、土石材料类、植生工程类和再生材料类。工法所用材料之评估,分别就其功能性、生态栖地特性、经济性和材料再生特性进行综合指数评估。将材料整合评析,如种类、适用范围、使用条件、生命周期及各阶段对环境之兼容性等,进而归纳出生态工程应用材料的规划设计原则。     

云南坡耕地农业持续发展研究

坡耕地是农村生态环境中最脆弱的部分,当前坡耕地利用的重要任务是提高土地生产力和防止水土流失。云南省坡耕地农业持续发展的综合措施有：（１）水窖;（２）条带树篱种植,（３）育苗移栽和平衡施肥。     

近30 a黄淮海农作区冬小麦单产潜力的影响因素分析

该文以黄淮海农作区的7个农作亚区为研究区域,选择了区域内 21个典型站点,利用AEZ模型对各个亚区在1968－1977年（C1情景）和 1998－2007年（C2情景）2个时间段的冬小麦光温生产潜力和气候生产潜力进行分析,并对影响潜力变化的气象要素和冬小麦品种要素进行了评价,从时空尺度上探讨了产生潜力差异的原因。研究表明：30 a来黄淮海农作区小麦光温生产潜力、气候生产潜力均有一定程度的提高,平均分别增长了3.96 t/hm2、3.32 t/hm2,潜力大小为南高北低、东高西低;在小麦光温生产潜力影响因素中贡献率由大到小为：品种（0.44）＞气象（0.33）＞二者互作（0.22）;增长的贡献因地域而异,东北部亚区的光温生产潜力的增长是由于品种对产量增加的正效应抵消了气候因素对产量的负效应,而西南部的亚区的增长是由品种和气候二者的正效应共同起作用的;在黄淮海农作区,由于拔节-抽穗期间降雨减少,水分亏缺增大,从而导致水分对气候生产潜力限制作用增大。     

基于文献计量分析的生态系统恢复力研究进展

该文基于VOSviewer和Histcite文献计量方法,以CNKI数据库和Web of science核心合集中生态系统恢复力研究文献为对象,通过对文献数量、高频关键词的分析,总结国内外恢复力研究的脉络和内容演变.研究发现:1)生态系统恢复力研究领域发表的文章数量总体上呈上升趋势,文献主要来源于美国;2)国际恢复力研...     

Soil quality and other factors influencing maize yield in northern Ghana

Food security is a crucial issue in sub‐Saharan Africa as a consequence of unreliable rainfall, marginal soil fertility and a low level of inputs leading to declining crop yields. As a case study, we investigated the most important variables affecting maize yield in northern Ghana. We combined a soil quality index on a continuous scale with a social data set to model maize yield using linear multiple regression. Five significant variables have been identified (P < 0.05): soil quality index, fertilizer use, household size, distance from main market, and the interaction between fallow length and soil quality index. The effect of the interaction between soil quality and fallow on maize yield is negative, suggesting the influence of litter quality and N immobilization in the soils. Research and policy should focus on the development of site‐specific, legume‐based cropping, and the integration of crop and livestock farming in Northern Ghana and similar areas in sub‐Saharan Africa.     

高等植物细胞的Ca2+-ATP酶

本文对高等植物细胞的Ca2 ATP酶的分布、功能、生化特性和分子生物学等方面的研究进展作了较为系统的综述。     

基于能值分析的农业园区循环经济发展评价研究

为促进农业循环园区降低资源消耗和减少污染,实现农业现代化的新要求,该文构建了农业园区循环经济系统能值评价指标体系,以西北某农业科技园区为例进行评价。结果表明:该园区经济发展程度整体较好,但二三产业发展较为薄弱;园区能值投资率为8.06,能值产出率为1.12,能值再利用率为29.27%,整体资源再利用程度偏低;园区环境负荷率为8.11,废弃物能值比为11.57%,废弃物利用率为69.61%,废弃物资源化利用程度有限;可持续发展指数为1.61,改进的可持续发展指数为3.42,生态效率指数为0.88,产业结构较为单一且不均衡。建议园区改善资源利用,优化产业结构,增加系统强度和生产效率。该研究对国内其他农业园区循环经济的发展评价也有借鉴意义。