华南农业大学农事训练课程的理论与实践——以养蚕与缫丝课为例     

黄志君 《安徽农业科学》2017,45(20)

以养蚕与缫丝课程模块为例,对其课程内容安排、教学特点、考核方法进行分析,并对其所面临的问题展开探讨,旨在为进一步提高相关实践教学效果提供借鉴。  相似文献   

Digital mapping of soil salinity at various depths using an EM38     

Bhaskar Narjary  Murli Dhar Meena  Satyendra Kumar  Sushil Kumar Kamra  Dinesh Kumar Sharma  John Triantafilis 《Soil Use and Management》2019,35(2):232-244

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北方农牧交错带农田生态系统健康评价 ——以武川县为例     

lcylp@sohu.com 《勤云标准版测试》2006,(3)

采用生态系统健康的理论和评价方法分析评价农田生态环境问题具有重要的理论和现实意义,应用生态健康指数定量评价农田健康水平是生态系统管理的重要内容。以武川县农田为研究对象,选择水分、生物量、幅宽等代表性指标,分析了不同作物覆盖下农田生态健康指数。结果表明:不同种植模式间农田健康指数差别明显。播种期较早的小麦田最为健康,没有采用地膜覆盖的马铃薯田健康指数最低,而采用地膜覆盖的马铃薯田健康指数比较高。推广小麦栽培和覆膜栽培是北方农牧交错带农田很好的经营管理模式,具有推广价值,是缓解该地区环境的有效手段之一。  相似文献   

Effect of the Pietrain breed used as terminal boar on Post-weaning Multisystemic Wasting Syndrome (PMWS) in the offspring in four PMWS-affected farms     

Nicolas Rose  Alain Abhervé-Guéguen  Gérald Le Diguerher  Eric Eveno  Jean-Pierre Jolly  Philippe Blanchard  Aurélie Oger  André Jestin  François Madec 《Livestock Production Science》2005,95(3):177-186

The aim of this study was to determine the potential risk factors for PMWS at the individual pig level and assess the effect of the Pietrain paternal genetic background of the animals in a cohort study. The survey was set up in four PMWS-affected farms with 2 repetitions (batches) per farm. A representative sample of 60 pigs per batch, stratified according to the paternal genetic background (Pietrain: yes vs. no), was randomly selected after farrowing. The representative cohort was divided into 8 batches and the pigs were individually monitored from birth to slaughter. Survival analysis was used to determine the factors related to the time to PMWS. The litter-cluster effect was taken into account using the marginal Cox model (robust estimation of the covariance matrix) and the gamma shared frailty model which were compared.No protective effect of the Pietrain breed on the time to PMWS and the proportion of affected pigs in the offspring was found in this study. Piglets showing low circovirus type 2 (PCV2) titres at 7 weeks-old with no subsequent seroconversion and piglets from PCV2 negative sows were most likely to be affected by PMWS (HR=7.0 and 2.8, respectively). Active infection of the pregnant dams with parvovirus was related to an increased risk of PMWS in the offspring (HR=2.3). Neck injuries due to poorly performed injections in the dams were associated with an increased risk of PMWS with the marginal model (HR=2.1). Oxytocin injection (dams) during farrowing was protective against PMWS in the offspring (HR=0.6).  相似文献   

Environmental assessment tools for the evaluation and improvement of European livestock production systems   总被引：1，自引：0，他引：1  

Niels Halberg  Hayo M.G. van der Werf  Randi Dalgaard 《Livestock Production Science》2005,96(1):33-50

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Mechanisation of organic fertiliser spreading,choice of fertiliser and crop residue management as solutions for maize environmental impact mitigation     

《European Journal of Agronomy》2016

The environmental impact of crop production is mainly related to fossil fuels consumption and to fertilisers application. Emissions arising from the spreading of organic and mineral fertilisers are important contributors for impact categories such as eutrophication and acidification. The choice of the fertilisers and of the spreading techniques as well as the crop residues management can deeply affect the environmental impact related to crop cultivation.In this study, seven scenarios describing fertilising schemes characterised by different organic and mineral fertilisers and by different mechanisation were compared. The aim is to evaluate, using the Life Cycle Assessment (LCA) method, how the environmental performances of grain maize production were affected by these different fertilisers schemes. The study was carried out considering a cradle to farm gate perspective and 1 t grain maize was selected as functional unit. Inventory data were collected on a farm located in Po Valley (Northern Italy) during year 2013 and were processed using the composite method recommended by the International Reference Life Cycle Data System (ILCD). The compared scenarios involved organic and mineral fertiliser distribution and were: pig slurry incorporation after >3 days after spreading (BS), fast pig slurry incorporation within 2 h from spreading (AS1), direct soil injection of pig slurry (AS2), pig slurry incorporation (after >3 days) with straw collection (AS3), digestate spreading instead of pig slurry (after >3 days) (AS4), only mineral fertilisers (i.e. urea and superphosphate) distribution (AS5) and only mineral fertilisers (i.e. calcium ammonium nitrate and superphosphate) distribution (AS6).The results were not univocal, since climate and soil conditions as well as physical and chemical fertiliser characteristics differently affected the environmental load, especially for particulate matter formation, terrestrial acidification and terrestrial eutrophication impact categories. AS1 and AS2 showed the most beneficial results for these impact categories (between ↙67% and ↙73% respect to worst scenario). AS6, on the opposite, showed the highest environmental impact for those impact categories mainly affected by energy and fossil fuel consumption (climate change, ozone depletion, human toxicity with carcinogenic effect, particulate matter, freshwater eutrophication, freshwater ecotoxicity and mineral, fossil and renewable resources depletion), categories on which AS3 and AS4 were the best solutions. AS3 was the most impacting for terrestrial acidification and eutrophicationA sensitivity analysis was carried out varying grain maize yield (mostly affected: marine eutrophication) and ammonia volatilisation losses due to organic fertilisers (mainly affected: terrestrial acidification and eutrophication).The achieved results can be useful for the development of ⬓spreading rules⬽ that drive the application of organic fertilisers in agricultural areas where there is an intense livestock activity.  相似文献   

某水库建设项目地质灾害危险性评估   总被引：2，自引：0，他引：2  

杨恩祈  牛雪妮  魏中林 《安徽农业科学》2016,(4):96-99,105

通过野外调查、室内分析研究了评估区的地质环境条件,主要包括环境地质、水文地质和工程地质;结合建设项目可行性研究报告、岩土工程勘察报告,对某水库建设项目地质灾害危险性进行了现状评估、预测评估以及综合性分区评估;对拟建场地进行了适宜性评价,并提出了地质灾害防治措施。  相似文献   

Using indicators to assess the environmental impacts of wine growing activity: The INDIGO® method     

《European Journal of Agronomy》2015

Environmental assessment methods are needed by agronomists working on the enhancement of cropping systems to meet the demand for more sustainable farming practices. A growing number of operational methods based on a set of indicators have been designed, more for arable crops and livestock than for perennial crops like viticulture. Among them, the INDIGO^® method, originally developed for arable crops, offers a compromise between feasibility and predictive quality. Here we present a modified and expanded version of INDIGO^® for viticulture. The development of new indicators specific to viticulture and the adaptation of existing ones followed a five step approach: (i) preliminary definition of the objectives and identification of the end-users, (ii) construction of the indicator, (iii) selection of a reference value, (iv) sensitivity analysis and (v) validation. Stakeholders from professional institutions and winegrower organizations were closely associated with step (i) to define the framework and step (ii) to supply technical databases. We designed INDIGO^® indicators with all available scientific and expert knowledge which was aggregated into expert systems associating fuzzy subsets or, when possible, quantitative equations.Four indicators; pesticides, nitrogen, energy and soil organic matter, were directly adapted from the initial INDIGO^® method, whereas soil cover and frost protection management were new indicators. Potentialities of their use are highlighted by examples of implementation on different scales and for various purposes.  相似文献   

Molecular prevalence,risk factors assessment and haemato-biochemical alterations in hepatozoonosis in dogs from Punjab,India     

《Comparative immunology, microbiology and infectious diseases》2017

Hepatozoonosis caused by Hepatozoon canis is an important tick-borne disease of dogs in tropical and sub-tropical regions throughout the world. In the present study evaluation of blood samples collected from 225 dogs presented at Small Animal Clinics, GADVASU, Ludhiana, Punjab (India) was done for the presence of H. canis by PCR based assay targeting a portion of 18S rRNA gene. Of the total samples subjected to PCR, an amplicon of 666 bp was detected in 13.78% samples whereas, routine blood smear examination revealed gamonts in 5.78% samples. Furthermore, prevalence of H. canis infection was found to be significantly associated with season, being highest in summer and lowest in winter while other risk factors e.g. age, sex and breed showed non-significant association. In terms of various clinico-pathological parameters, significant drop in haemoglobin, total red blood cell count, packed cell volume and lymphocytes were recorded in positive cases whereas the total white blood cell count was non-significantly increased. The haematological alterations in the positive cases were lymphopenia, anaemia, thrombocytopenia, relative neutrophilia, neutrophilic leucocytosis, eosinophilia, monocytosis and lymphocytosis while the biochemical profile revealed hypoproteinemia and increased levels of blood urea nitrogen and creatinine (in positive cases) pointing towards renal failure.  相似文献   

Serological survey of Toxoplasma gondii in captive nonhuman primates in zoos in Spain     

《Comparative immunology, microbiology and infectious diseases》2019

Toxoplasma gondii is a widely distributed zoonotic protozoan parasite, which can affect most warm-blooded species. Some species of non-human primates (NHPs) are highly susceptible to T. gondii infection. The aim of the study was to determine the seroprevalence and risk factors associated with T. gondii infection in NHPs housed in zoos in Spain. Sera from 189 NHPs belonging to 33 species were collected in eight zoos. Additionally, 10 of the 189 animals were longitudinally sampled. Anti-T. gondii antibodies were detected in 48 NHPs (25.4%; confidence interval of 95% (CI_95%): 19.2–31.6) using a modified agglutination test (MAT; cut-off = 25). Seropositive animals had titers of 25 (6.3%), 50 (8.3%), 100 (8.3%) and ≥500 (68.8%). Seropositivity was detected in 15 of the 33 species (45.5%). Of the 10 NHPs sampled more than once, two animals (one Barbary macaque [Macaca sylvanus] and one common chimpanzee [Pan toglodytes]) seroconverted along the study period, while one seropositive chimpanzee increased antibody titers over time. The Hominidae family (OR = 5.9; CI_95%: 2.7–12.8) and sex (females) (OR = 2.1; CI_95%: 1.1–4.1) were risk factors potentially associated with seropositivity to T. gondii. Our results evince a widespread circulation of T. gondii in NHPs in zoos in Spain, which may be of conservation concern. Control measures should be implemented to minimize the risk of exposure of these species to T. gondii.  相似文献