Conflict at the Rural/Urban Interface: Mushroom Farms and Composting in a Suburbanizing Environment

Major complaints, nuisance suits, and vandalism threaten the ability of farms in suburbanizing areas to survive as development occurs around them. This is a particular concern in one county in southeastern Pennsylvania, an area of rapid population growth but also the nation's most productive mushroom producing area. This study examines mushroom growers' indications that on-farm composting is a major source of complaints from nonfarming neighbors. The study found that the size of the farm and the number of homes nearby were significantly more important factors than composting in explaining which mushroom farms receive complaints.     

Assessing Sources of Information for Urban Mushroom Growers in Accra,Ghana

This study assessed information sources for urban mushroom farmers in Accra, Ghana. One hundred farmers were sampled, and a structured questionnaire was administered to solicit information from the respondents. Results showed that the majority of farmers were male (71%) and most (60%) with university education. The majority (44%) had 1–5 years of experience in mushroom cultivation. Co-farmers (89.8%), the Mushroom Growers Association (79.6%), training workshops (73.5%), and the Farmers' Forum (29.6%) readily served as information sources for farmers. The research revealed that, for 52% of farmers, ignorance of information sources was a major hindrance in their quest for information.     

Compositional Changes in Composts During Composting and Mushroom Growth: Comparison of Conventional and Environmentally Controlled Composts from Commercial Farms

Samples from conventional and environmentally controlled (EC) composts taken at various stages of composting and mushroom (Agaricus bisporus) growth were analyzed for changes in 80 percent ethanol and water extracts, monosaccharides in acid hydrolysates of polysaccharides, lignin concentrations and lignin structural features. The relative lignin content of all composts as measured by the acetyl bromide procedure increased, both during composting and mushroom growth. On the assumption that the absolute amount of lignin remains unaltered during composting and mushroom growth, the relative changes to the polysaccharide concentrations were calculated. Thus, during composting, 70, 53 and 58 percent of the initial wall polysaccharides for conventional, “cold” and “hot” EC, respectively, were consumed by compost microorganisms. During spawn running and fruiting, about 15 percent of wall polysaccharides were utilized from all types of composts. Thus, considerable amounts (17–31 percent) of polysaccharide remained at the end of mushroom production. During composting, there were changes in the degree of condensation and in the extent of oxidation of the lignins in all cases, but the rate and extent of these changes was dependent on the different composting regimes. During mushroom growth, further changes occurred, again with different patterns for the different compost types.     

吉林省统筹城乡发展中农村土地流转影响因素研究

以城乡统筹为背景,从探讨城乡统筹与农村土地流转关联机制入手,运用因子分析和灰色关联度相结合的方法,探讨了吉林省统筹城乡发展中影响农村土地流转的主要因素及其影响程度,并提出控制城镇住宅投资速度及鼓励和帮助高投入低产出的农户积极寻求土地利益比较高的产业,提高土地利用率,优化产业结构的建议。结果表明:(1) 影响吉林省统筹城乡发展中农村土地流转的3个主要因素全社会住宅投资、农村城镇比较收益、农业中间消耗与农村土地流转关联程度依次为:0.788 0,0.692 3,0.644 7;(2) 全社会住宅投资与农村土地流转数量呈高度正相关;(3) 农村城镇比较收益与农村土地流转数量呈负相关;(4) 农业中间消耗与农村土地流转数量呈正相关。     

城乡河道生态治理与景观修复 ——以河北省滦平县牤牛河为例

以河北省滦平县牤牛河为研究对象,对城乡干涸、断流的中型河道进行了问题分析,并针对河道存在的淤积严重、水源不足、水体污染、河岸边坡破损严重、河道形态直线化严重、景观差等六大问题,提出了常用的生态治理手法及景观修复的要点,使河道整体设计在满足行洪的前提下,达到水质改善、生态修复、景观建设的目的.     

水土保持是城乡环境治理的生力军——广元市庭园水土流失综合治理实践与探索

庭园水土流失综合治理是城乡环境治理的客观要求,是推进城乡(特别是农村)环境治理的重要内容和有效途径,是落实实践科学发展观的具体体现。广元市经过多年实践与探索,总结出庭园水保模式,它对改善生态环境、调整产业结构、改善人居环境、提高农民生活质量,推动城乡环境政治,都有着十分重要的意义和作用。     

开展城乡水环境整治 建设绿色生态家园

开展城乡水环境整治,建设绿色生态家园,是当前开展城乡环境整治的重要内容,在分析水环境面临的短缺、污染、流失等影响因素的基础上,提出了水环境生态建设的目标、工程措施与防污节水措施、资金筹措等措施,以实现山川秀美、河水清澈、鸟语花香、环境宜人的新威远。     

政府主导型城乡建设用地的增减挂钩效益研究

[目的]分析政府主导模式下的城乡建设用地增加挂钩项目效益的特征,为完善增减挂钩制度提供依据。[方法]以湖北省内的3个政府主导型增减挂钩项目作为研究对象,从经济、社会、生态效益3方面选取15个指标构建城乡建设用地增减挂钩项目效益评价指标体系,运用层次分析法和模糊综合评价法,测度增减挂钩项目在实施前后的经济、社会、生态效益以及综合效益的隶属度。[结果]在政府主导模式下,3个增减挂钩项目的综合效益隶属度的增长率分别为21.56%,19.13%,21.94%,增长幅度一般,但较为稳定,其中社会效益增长最大,其次是经济效益,而生态效益小幅度下降。[结论]完善相关政策制度,加强政府对关键环节的监控,同时引入市场机制,可以弥补政府主导模式中的资金缺乏和效率低下等问题。     

城市和农村的生态系统与环境问题比较

随着经济的发展,我国农村城镇化、工业化和城市都市化的进程越来越快,由此而带来的一系列环境问题和水土流失问题日益引起我国政府和人民的关注.城市和工矿区水土保持问题是亟待研究的重要课题之一.针对我国水土保持界过去集中研究农村水土保持而较少研究城市水土保持问题的状况,比较了城市和农村生态系统与原始自然生态系统的差异,探讨了城市在特定条件下的环境问题,为分析与研究城市水土流失和水土保持提供了参考.     

Pollutant Exchange at the Water/Sediment Interface in the Venice Canals

The space-time distribution of some pollutants (Cu, Ph, Zn, Cd, Fe, Mn, V, Ni, Cr) in the sludge of the canals of Venice was studied. The contamination levels were comparable to, or higher, than those measured in the most polluted sediments of the Lagoon of Venice Sediments were collected by two different sampling techniques I ) collection of sediment cores (upper 5 cm) by a syringe-type corer, 2) collection by traps, placed on the bottom of the canal Traps pennitted the sampling of sediments essentially resuspended by overlying water turbulence This sediment fraction is subjected to variations of its physicochemical parameters (principally change of redox conditions) and therefore to pollutant exchange at the water/sediment interface The metals principally exchanged during sediment resuspension were Cd, Pb, Zn and Cu These metals have principally an anthropogenic origin and are bound to the most labile geochemical phases of the sediment (such as sulphides), which can be oxidised during sediment resuspension, releasing metals into the water Fe, Cr and Ni were only partially exchanged, while Mn and V were generally not exchanged, a significant fraction of these metals is of natural origin and is bound to the most refractory phases of the sediment.     

以信息服务推动城乡一体化进程的思路探讨

信息作为与物质、能量同等重要的战略性资源,在城乡一体化的发展中起着越来越重要的作用。高校图书馆可凭借信息资源优势、人才优势、服务优势推送信息服务,推进城乡一体化进程。对推送信息服务的思路进行了探讨,提出了推进信息服务的途径。     

Evaluation of Precipitation Composition at an Urban and a Rural Area for the Central Korean Peninsula

Precipitation samples were collected using wet-only samplers on a daily basis at Chunchon (rural area) and Seoul (urban area) from January to December in 1998. The pH, electrical conductivity, and the concentrations of major ions were analyzed. The volume-weighted annual average values of pH for both sites were identical. However, for volume weighted average pH of precipitations below 20 mm in Chunchon was significantly (p<0.05) lower than that in Seoul. The value of [NO₃ ^?]/[nss-SO₄ ^2?], calculated from average composition of rainfalls below 20mm, were 0.42 and 0.61 in Seoul and Chunchon, respectively. This supports that acidification of precipitation by nitrogen oxides, a part of which might be transported from the Seoul metropolitan area, caused the difference in pH between Chunchon and Seoul.     

金坛市土地生态质量的城乡梯度规律研究

金坛市作为长三角经济发达地区的典型地区,快速城镇化背景下其土地生态状况具有代表性。从基础、胁迫、结构、效益4个角度构建土地生态指数指标体系,以行政村为评价单元计算4个准则层分值和土地生态指数综合分值,在此基础上假设金坛市土地生态质量分布具有城乡梯度的规律。通过热点和梯度分析验证表明:（1）土地生态指数热点空间分异特征符合城乡梯度规律,城镇化是导致该规律的重要原因;（2）土地生态指数沿着金坛市“城镇—城乡结合部—近郊—远郊”环形梯度分布,总体上土地生态指数不断升高,沿城镇中心向外每增加2 400 m,土地生态指数提高1.6%;（3）城镇中心土地生态质量状况处于最低值,且城镇所在地土地生态质量比正常状态差,更精细地表明城镇化对土地生态质量的不良影响;区域土地生态结构是影响金坛市土地生态综合指数波动的最大因素。（4）该文对土地生态指数空间分异规律作了深入探究,对土地生态指数空间分异的驱动力分析和主控因子识别将在进一步研究中进行探索。该研究可引导政府在城镇化进程中实施改善土地生态质量的政策。     

共沉淀引发的溶解性有机质在水铁矿/水界面的分子分馏特性

土壤矿物与溶解性有机质（DOM）的相互作用会引起DOM在矿物/水界面的结构分馏,进而影响DOM在土壤中的长期保存及其环境行为。水铁矿在环境中广泛存在,可通过两种不同方式（表面吸附或共沉淀）与DOM结合。目前,鲜有研究从分子尺度上揭示共沉淀反应诱发的DOM在水铁矿/水界面的结构分馏特性。针对此,通过共沉淀方式在C/Fe不同的溶液中制备水铁矿-DOM复合体,将传统光谱手段（如,紫外（UV）-可见光光谱、Fe K边X射线吸收光谱（XAS）等）和近年来兴起的电喷雾-傅立叶变换-离子回旋共振质谱（ESI-FT-ICR-MS）相结合,从分子水平解析共沉淀过程中DOM在水铁矿/水界面的结构分馏行为。结果显示：水铁矿-DOM复合体中Fe主要以水铁矿的形式存在,所占比例与C/Fe值有关,介于68.0%~95.9%之间。UV和ESI-FT-ICR-MS分析共同表明在共沉淀过程中,水铁矿优先固定DOM中具有高分子量的富含氧的芳香性组分（主要燃烧过程中产生的致密多环芳香类物质和维管植物来源的多酚类物质）,该分子分馏特性与前人报道的因表面吸附引发的DOM在水铁矿/水界面的分馏现象基本一致,表明无论表面吸附还是共沉淀,水铁矿均倾向于固定芳香性强的高分子量组分。此外,本研究率先发现水铁矿对DOM的结构选择性随反应时间呈一定动态变化,表现为：燃烧过程中产生的致密多环芳香类组分优先被固定在复合体中,随着反应推进,维管植物来源的多酚类组分被固定。本研究结果有助于深入理解水铁矿形成过程中,通过共沉淀作用影响DOM环境地球化学行为的分子分馏机制。     

浙江省城乡土地利用效率及耦合关系演变

[目的]对浙江省城乡土地利用效率及耦合关系演变进行研究,为实现区域可持续、内生性高质量发展提供决策支持。[方法]通过构建3阶段DEA模型对2006—2018年浙江省69个县(市、区)的城乡土地利用效率进行测度和评价,在此基础上利用耦合协调模型探讨城乡土地利用效率的协调水平及其时空演变特征。[结果](1)浙江省的城乡土地利用效率差距明显,规模水平是土地利用效率的主要影响因素;(2)各县(市、区)的城市用地效率水平差距小,而农用地效率的空间极化特征显著;(3)2006—2018年浙江省城乡土地利用的效率耦合度与协调度波动上升,城乡耦合度与协调度受取决于农业用地效率水平;(4)城乡土地利用效率协调度区域差异明显。[结论]浙江省城乡土地利用效率受外部环境影响大,加强乡村建设,提高农用地效率是实现城乡协调,达到高质量发展的关键。     

Composition,Use and Legislation of Spent Mushroom Substrate in the Netherlands

? In The Netherlands, 760,000 metric tons of Spent Mushroom Substrate (sold under the name Champost) were produced in 1993. The annual production is still rising. Analytical data concerning fertilizer elements like N, P, K, Ca and Mg, show that the composition of SMS has been fairly constant since the mid sixties. However, the last few years, dry matter, ash and phosphate content are decreasing due to reduced composting time and cropping cycle. Heavy metals and arsenic were not analyzed until 1983. In connection with manure surpluses in The Netherlands, a ‘Decree Use of Animal Manure’ was laid down as part of the Soil Protection Act, which dates from 1986. The Decree regulates the maximum quantity of manure that may be used, based on its phosphate content. The rules will be accentuated in the next few years. Since 1993, SMS falls under another item of the Soil Protection Act, the ‘Decree Use and Quality of Other Organic Fertilizers,’ controlling sewage sludge and all kinds of composts. The quantity that may be used depends on phosphate and heavy metal content. The total load of heavy metals, supplied per hectare, is controlled by limiting the amount of dry matter. Each year, 6 metric tons of dry matter may be used per hectare, provided that the compost is ‘clean’. To check phosphate and heavy metals, samples have to be analyzed regularly. In 1993, 620 samples have been analyzed. All compost fell within the category ‘clean’ and 17% was even characterized as ‘very clean.’ Production of vegetable, fruit and garden waste, a type of compost very competitive to SMS, is strongly increasing. Alternative ways of disposal of SMS will be discussed briefly.     

太湖流域规模畜禽养殖场污染特性的解析

通过对江苏省太湖流域水污染防治一级保护区内规模畜禽养殖场的调查 ,揭示了其污染物的存在方式、处理形式等特性。调查表明 ,规模畜禽养殖场并非是构成太湖水质下降的“污染大户” ,为正确探索太湖水质下降的成因和防止太湖水质继续恶化 ,提出了新的思路和建议。     

珍稀食用菌绣球菌液体发酵工艺条件优化

为研究绣球菌最适的液体发酵条件,同时保证其多糖的产量,以绣球菌菌丝干重和胞外多糖(EPS)产量为评价指标,采用单因素和正交试验L9(34)优化绣球菌液体发酵工艺。结果表明,最佳液体发酵工艺条件为:碳源为葡萄糖,氮源为蛋白胨,无机盐为硫酸镁,pH值5.5,C/N=20/1,培养温度27℃,此工艺条件下菌丝干重和EPS产量最高,分别为1.5 g·L~(-1)和2.87 mg·L~(-1)。本研究结果为绣球菌后续的相关研究提供了理论依据。     

重庆城乡统筹试验区土地利用平衡研究

土地利用平衡问题的产生大多由经济发展的驱动所引起,而用地间的相互消长形成最终的土地利用格局。使用历史统计、资料文献等数据,运用数理统计方法,分析近年来重庆城乡统筹试验区土地利用平衡的轨迹及其面临的困境,然后提出相应的对策建议。结果表明:①近年来随着开发整理(复垦)的力度逐渐加大,其已经成为增加耕地的首选,是实现区域内土地利用平衡的重要途径;②重庆市在实现土地利用平衡中面临的困境主要表现在耕地浪费严重、农村建设用地利用不规范、土地利用效率低下、用地布局不合理、后备资源挖潜难度加大、生态损耗突现等;③针对以上问题,需要建立土地集约利用的激励机制、进一步规范集体建设用地流转、培育和规范有形的土地市场、编制科学的土地利用规划等,有助于平衡重庆区域内的土地利用格局。