农业节水投资与效益分析方法初探

根据农业节水投资与效益分析现状及存在的主要问题分析基础上 ,研究提出了农业节水投资估算的成本法、统计分析法、直接估算法 ,对投资估算方法的应用进行了评价 ,分析介绍了我国农业节水规划目标、农业节水规划措施及规模及节水规划投资估算 ,此外从定性 (从社会和环境效益 )和定量 (经济效益 ) 2大方面研究了节水的效益及计算     

小田块变量施肥系统优化设计与应用

针对苏南地区推广变量施肥存在的施肥策略过于精细化导致高密度土壤信息不易获取和普通的施肥机械难以达到播量精度等主要技术障碍,该文建立了一种简单实用的变量施肥方案,在现有机械式播种施肥机基础上进行了自动化改造,构建了一套基于简易电子处方图系统的变量施肥系统;变量施肥作业时,以单个自然田块为处理单元,依托所建立的简单实用的电子处方图系统,实现多种肥料按需配比、同一田块均匀施肥、不同田块变量施肥的功能。为提高播量精度和播量稳定性,对普通精度GPS模块的数据进行了差分和卡尔曼滤波处理,对外槽轮施肥播种器结构进行了优化设计。田间试验结果表明：电子处方图运行结果准确,施肥播种机工作稳定,种子和肥料的最大和平均播量误差分别为3.91%和2.09%,最大和平均动态误差分别为4.52%和1.48%。该研究可为苏南小田块地区推广变量施肥提供技术参考。     

内蒙古杭锦旗北部盐碱田温湿盐动态与生产利用

为探析水-热-盐关系以及植被对盐碱田改良的意义,利用2008年8月2日-8月6日在内蒙古杭锦旗黄河灌区盐碱田进行的试验观测数据,主要通过方差分析与典型相关分析方法对3个样地(裸地、紫花苜蓿地和玉米地)土壤温度(0-30cm土层)、湿度(0-20cm土层)、盐度(0-100cm土层)的动态变化进行了分析。结果表明,3个样地的温(度)-湿(度)-盐(度)动态基本呈现裸地苜蓿地玉米地的格局;0-5cm地温与耕作层(0-20cm)的土壤水分具有显著相关关系,是0-30cm土层内地温驱动水盐动态的主要热力因子;植物能够减少土壤表层积盐,并可以降低碱化度;苜蓿地比玉米地具有更低的钠吸附比值。在盐碱地区选择耐盐碱牧草品种开展草田轮作,有益于盐碱土壤的改良与利用。     

推进农村信息化建设促进区域农村经济快速发展

当前,信息化已经成为最先进、最活跃的生产力,随着信息技术在农村的快速渗透和应用,农村信息化已经成为农村现代化的重要内容和标志。针对建设社会主义新农村、构建和谐社会的新任务,进一步加快农村信息化进程,着重分析了衡水市农村信息化的现状,探讨了推进衡水市农村信息化的举措。     

论有机畜牧业之发展

本文论述了有机畜牧业产生的背景,并明确了有机畜牧业的内涵。通过分析国外有机畜牧业发展历程、认证标准,着重探讨我国发展有机畜牧业的优势和必要性,并给出了切实可行的建议和思路。     

精准农业在苜蓿产业化生产中的应用研究

在苜蓿生产和农业生产的各项物质投入中,肥料是费用最高的一项。把精准农业用于苜蓿产业化生产,对苜蓿生产肥料投入能达到减少浪费、增加收入、保护农业资源和控制环境质量的目的。     

A political tsunami hits Amazon conservation

1. The history of conservation of the Amazon can be viewed as a war involving many battles with interests in agribusiness on one side and in biodiversity conservation and sustainability on the other side. Trends in large-scale deforestation in the 1970s spurred a series of policies, stakeholder alliances and international and grass-roots movements, which decades later led to the establishment of protected areas and interventions in soy and beef supply chains of agribusiness. Together, these advances epitomized a conservation framework for the Amazon, which at one point nearly curbed deforestation in the Brazilian Amazon, although it included very few protections for freshwater ecosystems.
2. While those conservation advances were taking place, however, a series of policy changes started to undermine them through expansions in deforestation, river regulation and mining activities. The election of Brazil's President Jair Bolsonaro in 2019 then hit the Amazon conservation framework much like a tsunami of policy setbacks and the re-establishment of the economic policies that sparked the Amazon war in the past.
3. The current trajectory is one of large-scale degradation of Amazonian ecosystems and biodiversity with consequent impacts on local people. Because freshwater ecosystems are highly sensitive to human activities on water and on land, these growing impacts are particularly large.
4. It is too early to know, but four decades of institutional and policy developments to conserve the Brazilian Amazon may soon be pushed past the point from which they will be able to recover. Four conditions will be pivotal to allowing the Amazon conservation framework to recoup: (a) the end of Bolsonaro’s mandate in 2022 or earlier; (b) remobilization of stakeholders; (c) investments in environmental research, policy and multiple collaborations; and (d) moving conservation beyond terrestrial landscapes to also encompass freshwater ecosystems and their people.

     

Decomposition processes in coastal lagoons and their implications for the assessment of ecological health

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A critical appraisal of appendage disparity and homology in fishes

Fishes are both extremely diverse and morphologically disparate. Part of this disparity can be observed in the numerous possible fin configurations that may differ in terms of the number of fins as well as fin shapes, sizes and relative positions on the body. Here, we thoroughly review the major patterns of disparity in fin configurations for each major group of fishes and discuss how median and paired fin homologies have been interpreted over time. When taking into account the entire span of fish diversity, including both extant and fossil taxa, the disparity in fin morphologies greatly complicates inferring homologies for individual fins. Given the phylogenetic scope of this review, structural and topological criteria appear to be the most useful indicators of fin identity. We further suggest that it may be advantageous to consider some of these fin homologies as nested within the larger framework of homologous fin‐forming morphogenetic fields. We also discuss scenarios of appendage evolution and suggest that modularity may have played a key role in appendage disparification. Fin modules re‐expressed within the boundaries of fin‐forming fields could explain how some fins may have evolved numerous times independently in separate lineages (e.g., adipose fin), or how new fins may have evolved over time (e.g., anterior and posterior dorsal fins, pectoral and pelvic fins). We favour an evolutionary scenario whereby median appendages appeared from a unique field of competence first positioned throughout the dorsal and ventral midlines, which was then redeployed laterally leading to paired appendages.     

马铃薯田间迁飞蚜种类及发生时期调查初报

采用黄板诱捕的方法,查得青海东部马铃薯田间的迁飞蚜隶属３科,１２属,１９种,其中已知的主要种类有桃蚜、酸模蚜等１４种。据观察,该地区薯田的迁飞蚜出现于５月下列至９月上旬,不同地区的迁飞期随海拔升高而相应推迟,虫种数也趋于减少。