农户过量施用化肥行为的影响因素分析——以新疆棉花种植户为例   总被引：3，自引：0，他引：3  

玛衣拉·吐尔逊  甫祺娜依·尤力瓦斯  阿斯亚·托乎提 《棉花学报》2016,28(6):619-627

过度施用化肥带来的负外部性使棉区土壤面临着棉花增产和保护生态环境的双重挑战。本文在棉花生产的决策主体农户尺度上,利用对新疆重点植棉地区实地问卷调查所得数据,定量化研究了新疆棉农过度施用化肥程度,并通过经济计量模型分析了导致农户过量施用化肥的主要因素。研究结果表明,新疆棉花种植农户的化肥施用量(折纯量)平均达到610.20 kg·hm~(-2),过量施用率占到实际施用量的59.6%。导致农户过量施用化肥的主要因素是缺乏科学施肥培训和避免收入损失的盲目性。研究结果在农户行为学方面做了有益的科学探讨,并为科学引导农户合理施肥提供了科学依据。  相似文献   

基于B-S模型的环保项目投资评价     

韦宁  韩帅奇  马城楠  王宗良  张亚旭  江馨 《安徽农业科学》2016,(8):254-256

以ABC公司环保产品开发为例,针对传统项目投资评价在环保项目上的缺点,分析了将实物期权理论运用到环保项目投资评价中的可行性,并运用B-S模型进行定量分析,以期为环保项目投资提供一个新的思路,同时也使环保项目决策变得更加合理。  相似文献   

乌鲁木齐市空气污染成因及防治对策探讨     

廖银念  苏玉红  艾尼瓦尔·买买提 《湖北农业科学》2011,(21):4378-4380

分析了乌鲁木齐市1999～2009年间每年以及2005～2007年各月份空气环境质量中主要污染物SO2、NO2、PM10的监测结果 ;探讨了造成该市空气污染的自然条件、城市功能布局、能源结构、供热点分布、移动源、监测和治理能力等因素,并从改善生态环境、优化工业布局、加强污染治理、调整能源结构、推进节能工作、防治机动车尾气排放、提高监测能力及公众意识等方面提出了污染防治的对策和建议。  相似文献   

基于DLMS/COSEM的嵌入式自动抄表集中器的设计与实现     

杨兴春  熊邦毛 《湖南农业大学学报(自然科学版)》2011,(2):49-52

环境污染责任保险因开展经验及历史数据不足致费率难以合理厘定，引入模糊信息粒及综合评价理论，相对传统方法，更能实现费率厘定的公平合理，保障各方利益.本文以化学原料及化学制品制造业为研究对象，首先运用模糊信息粒理论处理历史数据，克服数据模糊不确定性，得出第三者赔偿额的模糊信息粒X~；其次运用传统精算定价方法得出行业基准费率的模糊信息粒p~；最后运用模糊综合评价二级评价理论，综合追溯期、企业规模等影响因素，得出投保企业风险综合评价集B~，以此修正基准费率.  相似文献   

Efficient reduction of biomass,seed and season long pollen production of common ragweed (Ambrosia artemisiifolia L.)     

《Urban Forestry & Urban Greening》2017

Ragweed (Ambrosia artemisiifolia L.) is a noxious plant that not only is a troublesome agronomic weed that causes economic damage to agricultural crops but also − and even more importantly − causes severe health problems due to its severe allergenicity. The pollen of invasive ragweed has become a major allergenic risk factor in urban areas in newly occupied regions. Many urban areas prohibit herbicide application; thus, mowing is the most widely used control measure. Counting pollen is labour intensive; therefore, pollen production data are mainly based on estimations. Field experiments were conducted to determine the effects of different mowing scenarios, plant density and cutting height on the biomass, pollen production and seed production of common ragweed plants. Ragweed plants were mown twice: just before the flowering of terminal racemes (BBCH 59) and when the flowers of the re-sprouting lateral shoots reached BBCH 59. A 1- to 3-cm cutting height produced the greatest pollen reduction compared to that of intact control plants (94%) based on a season-long pollen collection. The number of female flowers also significantly decreased (97%). Compared to the control, the onset of pollen discharge was delayed by 5 weeks and the length of the pollen discharge period decreased from 9 to 4 weeks. The season-long unique and reproducible pollen production data can be integrated with airborne pollen modelling and population management strategies.  相似文献   

沿滩区环境监测能力现状与建议     

刘梦 《安徽农业科学》2015,(13)

随着社会经济的快速发展,环境保护越来越被人们所重视.环境保护部门肩负着重要的使命和神圣的职责,而环境监测又是环境保护的关键环节,它将为搞好环境保护工作提供有效的技术支持与服务.因此,环境监测能力的高低势必会影响监测质量的好坏.分析了沿滩区环境监测能力的现状和存在的问题,提出了相关建议,使环境监测为环境保护工作提供有效的技术支持与服务.  相似文献   

Community structure of arbuscular mycorrhizal fungi associated with Robinia pseudoacacia in uncontaminated and heavy metal contaminated soils     

《Soil biology & biochemistry》2015

The significance of arbuscular mycorrhizal fungi (AMF) in soil remediation has been widely recognized because of their ability to promote plant growth and increase phytoremediation efficiency in heavy metal (HM) polluted soils by improving plant nutrient absorption and by influencing the fate of the metals in the plant and soil. However, the symbiotic functions of AMF in remediation of polluted soils depend on plant–fungus–soil combinations and are greatly influenced by environmental conditions. To better understand the adaptation of plants and the related mycorrhizae to extreme environmental conditions, AMF colonization, spore density and community structure were analyzed in roots or rhizosphere soils of Robinia pseudoacacia. Mycorrhization was compared between uncontaminated soil and heavy metal contaminated soil from a lead–zinc mining region of northwest China. Samples were analyzed by restriction fragment length polymorphism (RFLP) screening with AMF-specific primers (NS31 and AM1), and sequencing of rRNA small subunit (SSU). The phylogenetic analysis revealed 28 AMF group types, including six AMF families: Glomeraceae, Claroideoglomeraceae, Diversisporaceae, Acaulosporaceae, Pacisporaceae, and Gigasporaceae. Of all AMF group types, six (21%) were detected based on spore samples alone, four (14%) based on root samples alone, and five (18%) based on samples from root, soil and spore. Glo9 (Rhizophagus intraradices), Glo17 (Funneliformis mosseae) and Acau3 (Acaulospora sp.) were the three most abundant AMF group types in the current study. Soil Pb and Zn concentrations, pH, organic matter content, and phosphorus levels all showed significant correlations with the AMF species compositions in root and soil samples. Overall, the uncontaminated sites had higher species diversity than sites with heavy metal contamination. The study highlights the effects of different soil chemical parameters on AMF colonization, spore density and community structure in contaminated and uncontaminated sites. The tolerant AMF species isolated and identified from this study have potential for application in phytoremediation of heavy metal contaminated areas.  相似文献   

左右岸省界缓冲区水质达标评价方法研究     

许君雨  康峤  段海燕  李杰  王宪恩 《节水灌溉》2014,(11)

左右岸省界缓冲区作为协调省际间用水关系的重要水域,其水质达标评价及污染责任划分是流域限制纳污红线制度实施的重要内容。从左右岸省界缓冲区的相关概念出发,根据省份的位置关系将其分为缓冲区完全在两省省界上、缓冲区部分在两省省界上以及缓冲区在多省交界上三种情形,并结合左右岸省界缓冲区特点确定调整浓度核算法、代表断面判断法、限制排污总量-污染物入河量评估法等水质达标评价方法,以判断左右岸省份缓冲区的水质达标情况,从而划分缓冲区左右岸省份的污染责任。实例验证模拟显示,确定的方法切实可行,研究方法可为流域污染责任划分提供技术支撑,从而促进限制纳污制度的顺利实施。  相似文献   

中国农业面源污染排放的空间差异及其动态演变   总被引：4，自引：0，他引：4  

丘雯文  钟涨宝  原春辉  李兆亮 《中国农业大学学报》2018,23(1):152-163

以2003—2014年为研究时段,在测算农业面源污染排放强度的基础上,综合运用基尼系数和非参数估计方法,研究我国农业面源污染的空间差异及其动态演变,结果表明:1)我国农业面源污染排放总体下降,且表现出明显的空间差异,东部和中部地区的排放强度较高,西部和东北地区则相对较低。2)2003—2014年,中国农业面源污染排放强度的区域差异略微扩大,地区间差异是其总体差异的主要来源。3)核密度估计结果表明,中国农业面源污染排放总体差异表现为"下降-上升-下降"的波动变化趋势。4)马尔科夫链分析表明,中国农业面源污染在不同类型间的相互流动较为微弱,但从长期来看,存在向两极分化发展的趋势特征。  相似文献   

Environment and Feline Health: At Home and in the Clinic     

《Veterinary Clinics of North America: Small Animal Practice》2020,50(4):663-693

  相似文献