旱地果园双重覆盖对土壤及果树生长的影响          下载免费PDF全文

索改弟  谢永生  郝明德  揣峻峰  刘楠 《西北农业学报》2014,23(8):142-148

为探讨地膜-秸秆双重覆盖对旱地果园土壤肥力及其果树生产的影响,以渭北盛果期苹果树为对象,研究不同处理间苹果枝条、叶片养分含量以及土壤速效养分含量的动态变化。结果显示,不同覆盖措施(地膜压玉米秆、地膜压短麦秆、长麦秆压地膜和地膜压长麦秆)均能增加苹果叶片和枝条的养分含量、优化枝条比例,提高土壤水分和养分利用效率,改善苹果品质。其中地膜压短麦秆处理短枝比例、产量、优果率以及水分利用效率均为最高,枝条、叶片的养分含量较高,为最佳覆盖模式。  相似文献   

Could the dawn of Level 4 robotic weeders facilitate a revolution in ecological weed management?     

Charles N. Merfield 《Weed Research》2023,63(2):83-87

Ecological weed management (EWM) considers that not all non-crop plants cause harm, and that non-harmful species ‘aliae plantae’ should be retained to provide multiple positive benefits. Only plants causing ‘significant harm’ are defined as weeds and should be controlled. However, this is difficult to achieve with current herbicide and mechanical weeding technologies. Robotic weeders may be able to facilitate EWM. Four Levels of robotic weeders are defined: Level 1 are row followers; Level 2 identify individual crop plants and weed around them; Level 3 individually identify all plants and individually kill all non-crop plants; Level 4 weeders individually distinguish crop plants, aliae plantae, and weeds and only kill the weeds, thus facilitating EWM. Currently only Levels 1–3 robotic weeders exist. The aim of proposing Level 4 robotic weeders is to highlight, particularly to roboticists, that the end goal of robotic weeding should not be crop monocultures, but biodiverse fields through EWM. It is envisaged that Level 4 robotic weeders would not just operate in vegetable crops, which are the current focus of Level 3 weeders, but in all crops, such as fruit trees, where they could, for example, control weeds in living mulches. It is therefore considered essential that weed scientists and roboticists collaborate to ensure that robotic weeders achieve EWM, not monocultures. If this vision can be realised, it could usher in a revolution in weed management.  相似文献   

Feasibility study on the estimation of the living vegetation volume of individual street trees using terrestrial laser scanning     

《Urban Forestry & Urban Greening》2022

As an important part of urban greening, the canopy of street trees has ecological benefits, such as oxygen production, noise reduction, and dust reduction. The living vegetation volume (LVV) can reflect the spatial structure of the canopy intuitively and enables the estimation of the ecological service value of street trees. Terrestrial laser scanning (TLS) has shown excellent performance for providing three-dimensional data of individual trees with high precision, enabling the accurate quantification of the LVV. In this study, we divided the LVV into the total living vegetation volume (tLVV) and the effective living vegetation volume (eLVV); the latter does not include branches. The eLVV of 40 ginkgo trees separated in two roads in Nanjing was calculated from TLS data. A novel method named LAIM for accurate eLVV calculation based on point cloud data was proposed. The point cloud data of individual tree was segmented along the Z-axis and image processing methods were used. With this, eLVV of each tree was obtained. The results were compared with data obtained from a clustered point cloud generated using convex hulls. The Bland-Altman analysis was used to investigate the consistency of the two methods. Furthermore, we used correlation analysis and all-subsets regression to choose the variables, and the eLVV was fitted using six models. Finally, we evaluated O₂ production, CO₂ and SO₂ absorption by the street trees based on eLVV, the ecological benefits of street trees were quantified. The results showed the following: (1) The number of layers and the dilation size of the point cloud were crucial parameters in the LAIM. (2) For ginkgo trees, the mean difference between the eLVV obtained from the LAIM and the convex hull method was − 0.53–0.19 m³, indicating that the results were highly consistent for the two methods. (3) The eLVV fitting performance was better for the exponential function model (R² =0.8523, RMSE=0.6838 m³) and linear model (R² =0.8361, RMSE=0.7224 m³). The tree height and crown width significantly affected the eLVV estimation. (4) The evaluation about ecological benefits of Zhaoyang Road was better than Cuizhu Road. The quantified ecological benefits were conducive to road ecological evaluation. This study quantified the eLVV of individual trees using TLS, highlighting the importance of live vegetation in urban greening. The results can provide technical support for estimating the ecological service value of urban street trees.  相似文献   

基于"门槛-供需"耦合视角的县域农村生活可达性评价          下载免费PDF全文

杨兆晨  刘耀林  罗璇  安睿  姜永祯 《农业工程学报》2022,38(11):279-288

在乡村振兴背景下，农村生活设施布局优化对乡村发展、农村居民幸福感提升具有重要意义。针对农村可达性研究中评价对象与视角单一等问题，考虑四类生活设施，采用"面向服务需求的等时线分析方法"与改进的"两步移动搜索法"，从"门槛"与"供需"角度分析高安市农村生活可达性的空间分布特征，进而提出一种基于耦合视角的可达性分区模式，并探讨农村生活可达性的驱动机制与优化路径。结果表明：1）从最低时间成本来看，农村学前教育、大病就医、物流快递、文体活动均存在较大障碍，城乡发展的不均衡现象显著。2）从供需关系来看，教育资源与人口形成相对平衡的区域供需关系。部分乡镇中心医疗设施供给高于城区，商业与文体的供给普遍具有明显的城镇偏向性。3）基于"门槛-供需"耦合视角的农村可达性分区将高安市按四类设施分为高门槛-低供给、高门槛-高供给、低门槛-低供给、低门槛-高供给四种可达区和不可达区。农村生活可达性受空间阻抗与供需关系的影响，可从空间关系调整、生活设施与道路建设、生活服务服务要素流动三方面进行优化。研究可为县域农村生活设施、农村居民点的布局优化提供借鉴和参考。  相似文献   

适应与缓解：应对气候变化的21世纪人类世风景园林路径与策略          下载免费PDF全文

王贞  万敏 《华中农业大学学报》2023,42(4):16-22

健康的人居环境是人类社会一切发展的重要基石，但全球气候变化却使之深陷危机，“人类世”概念的提出为正确理解人与自然的关系奠定了科学的基础。风景园林作为连接人、场地和环境的一门学科，对激励和领导人居环境相关学科共同应对全球气候危机起到极其关键的作用。为应对人类世时代风景园林的挑战，本文梳理了人类世风景园林的特征，指出作为人类世首要表征的气候变化给风景园林学带来的广泛影响，通过在气候变化、人类世和风景园林三者之间建立逻辑联系，深入归纳应对气候变化风景园林需要明确的主要目标，并总结出一些可行的解决路径和策略。  相似文献   

英国乡村野生动植物保护措施的演变及启示   总被引：1，自引：1，他引：0  

张敏  严火其 《农业现代化研究》2021,42(3):537-544

野生动植物是农业生态系统的重要组成部分。然而,随着以"效率"为目标的现代集约化农业技术的推广,乡村野生动植物的生存受到前所未有的威胁。本文通过历史研究法和文献研究法,对英国乡村野生动植物保护措施的演变历史及其发展规律进行深入分析,探讨了当前我国乡村野生动植物保护的现状及存在问题,最后结合英国经验,为我国解决发展现代集约化农业过程中面临的乡村野生动植物保护问题提出政策建议。研究发现,英国早期野生动植物保护措施主要针对濒危、珍稀和受到严重威胁的野生动植物物种及其栖息地。20世纪60—70年代以后,随着现代集约化农业的发展,普通乡村野生动植物保护问题成为关注的重点,并逐渐在以往物种和栖息地保护模式基础上,发展出整体性景观尺度保护模式。"活景观"理论出现后,英国乡村野生动植物保护开始与乡村经济和社会发展等问题相结合。当前,我国农业正经历着一场集约化变革,乡村野生动植物的生存受到严重威胁,但现有保护措施依然存在不足。对此,可以借鉴英国经验,在加强乡村野生动植物保护科学研究的同时完善相关法律和政策。  相似文献   

脱贫地区农村人居环境现状及整治框架——以重庆某县为例          下载免费PDF全文

王永生  施琳娜  朱琳 《农业资源与环境学报》2022,39(2):417-424

为明确脱贫地区农村人居环境整治思路，本研究通过国家农村人居环境政策演变的梳理和典型县域农村人居环境整治现状的问卷调研，探讨脱贫地区农村人居环境整治框架。结果表明，2004年以来，历年中央一号文件分阶段强调农村基础设施建设、村庄环境整治和农村人居环境整治工作。调查县农业废弃物中农膜和棚膜未回收的村庄占比为29.33%和22.51%，但秸秆和畜禽粪便资源化利用程度较高；公共厕所、污水处理等基础设施的村庄普及率相对较低，农户院落闲置率和倒塌率分别为21.93%和13.28%，倒闭的种养企业厂房废弃率较高，农户卫生厕所普及率仅为57.44%。在脱贫攻坚与乡村振兴衔接期，农村人居环境整治工作应着力促进政府“自上而下”决策和社会组织及农户“自下而上”参与的有机结合，加强农户层面的卫生设施配套、移风易俗推进和环保意识提升等。  相似文献   

厨余沼泥基质对活体芽苗菜的影响研究     

李林章  王侃  章晓鹏  崔丽利  陈峰磊 《蔬菜》2023,(10):16-18

摘要：为实现资源化循环利用，研究厨余沼泥在活体芽苗菜生产中的应用效果，以厨余沼泥作为基质进行豌豆苗栽培试验，以清水为对照，测定生长指标，并对其营养品质及重金属含量进行检测。结果表明：与对照相比，厨余沼泥处理豌豆苗株高极显著增加28.54%，单盒净产量极显著提高12.63%；厨余沼泥处理豌豆苗的抗坏血酸含量提高7.67%，可溶性固形物含量提高28.07%，蛋白质含量提高45.69%，脂肪含量降低18.00%，营养品质较好；重金属含量均未超出食品安全国家标准限量值，食用安全，且效益较好。厨余沼泥可作为活体芽苗菜栽培基质。  相似文献   

异迟眼蕈蚊生物生态学特征及防治策略     

苟玉萍  毛亮  刘长仲  张克信  李春春  张强艳  张艳蕾 《草业科学》2022,38(4):654-663

本文综述了异迟眼蕈蚊(Bradysia impatiens Johannsen)的生物生态学特征及其防治策略.异迟眼蕈蚊对寄主植物食用菌和韭菜(Allium tuberosum)的适应性和嗜食性最佳;温度25℃、光周期L?D=16 h?8 h和光强度588 lx最有利于异迟眼蕈蚊种群增长;湿度与昆虫的生活习性及行为息息相关,但尚未见关于异迟眼蕈蚊在此方面的研究报道.目前,异迟眼蕈蚊的防治依然以化学防治为主,此外,昆虫病原线虫、捕食螨、苏云金芽孢杆菌(Bacillus thuringiensis)等生物防治技术以及日晒高温覆膜、趋性诱杀等物理防治方法也有较好的应用潜力.本文对异迟眼蕈蚊生物生态学特性及防治方法的相关研究进展进行了总结和阐述,以期为该虫的进一步研究提供基础的理论依据.  相似文献