农牧交错区农户生计分化及其对耕地利用的影响——以宁夏盐池县为例

农户生计与耕地利用之间的关系已经成为理解人地关系的重要切入点。论文以宁夏盐池县为例,在可持续生计框架下,从农户生计资本和生产要素配置两个角度,探讨农户生计分化及其对耕地利用的影响。结果表明：1）盐池县兼业户与非农就业户合计占调查农户的58%,农户非农化现象普遍;2）劳动力越多、人均耕地越少的农户,其家庭非农收入占比越高,生计资本是农户生计分化的“推力”;3）务农机会成本越高的农户其生计分化程度越高,务农机会成本是农户生计分化的“拉力”;4）随着生计分化程度的增加,耕地利用的生产要素投入强度呈递减态势,但是兼业户的耕地利用效率高于纯农户和非农就业户。农牧交错区同时面临着生态保护、农牧业生产、脱贫攻坚等挑战,政策制定需充分考虑当地农户的生计特征与人地关系的演变规律,加强非农就业引导,鼓励农户土地流转,促进农户生计多样化,实现生态、经济、社会效益“共赢”发展。     

Indicators of Biodiversity and Conservational Wildlife Quality on Danish Organic Farms for Use in Farm Management: A Multidisciplinary Approach to Indicator Development and Testing

Organic farming is expected to contribute to conserving national biodiversity on farms, especially remnant, old, and undisturbed small biotopes, forests, and permanent grassland. This objective cannot rely on the legislation of organic farming solely, and to succeed, farmers need to understand the goals behind it. A set of indicators with the purpose of facilitating dialogues between expert and farmer on wildlife quality has been developed and tested on eight organic farms. “Weed cover in cereal fields,” was used as an indicator of floral and faunal biodiversity in the cultivated land, and “uncultivated biotope area” on the farm was used as a general measure of wildlife habitats. Functional grouping of herbaceous plants (discriminating between “high conservation value” plant species and “competitive”/“ruderal” species) and low mobility butterflies were used as indicators of conservation value, especially focusing on the few sites left with considerable remnant conservation value. The dialog processes revealed that the organic farmers’ ideas and goals of conservation of wildlife quality were not necessarily the same as for biologists; the farmers expressed very different opinions on the biological rooted idea, that wildlife quality is related to the absence of agricultural impact. However, farmers also stated that the information given by the indicators and especially the dialogue with the biologist had influenced their perception and awareness of wildlife. We conclude that, combined with a dialogue process, using these indicators when mapping wildlife quality could be an important key component of a farm wildlife management advisory tool at farm level.     

FIELD SCALE MULTIOBJECTIVE DECISION MAKING: A CASE STUDY FROM WESTERN IOWA1

ABSTRACT: Water quality issues in agriculture are growing in importance. A common theme is the provision of better information to decision makers. This study reports the trial of a prototype decision support system by the U.S. Department of Agriculture Natural Resources Conservation Service and the Agricultural Research Service in the NRCS Harrison County Field Office in 1998. Observed data collected at the Deep Loess Research Station (DLRS) near Treynor, Iowa, were extrapolated using a modified GLEAMS field scale simulation model that included a nitrogen leaching component and a crop growth component. An accounting tool was used to convert crop yield estimates into crop budgets. A model interface was built to specify the climate, soil, and topography of the field, as well as the management scenarios for the alternative management systems. For the Deep Loess Hills area of Harrison County, a total of six soil and slope groups, with 66 total combinations of management practices forming management systems, were defined and simulated based on previously calibrated data from DLRS. A multi‐objective decision support system, the Water Quality Decision Support System, or WQDSS, was used to examine the tradeoffs in a comprehensive set of variables affected by alternative management systems with farmers in Harrison County. The study concluded that a multiobjective decision support system should be developed to support conservation planning by the NRCS. Currently, a larger scale effort to improve water quality decision making is underway.     

发展有机农业与生物多样性保护

本文通过在试验区(内蒙古磴口县)对常规农业和有机农业分别对生物多样性的影响进行了分析比较，结果表明：发展有机农业，能够促进生物多样性保护，如有益昆虫的数量增加，其中七星瓢虫最为明显，蚜虫的虫口密度降低，益鸟等生物的数量有所增加。充分说明有机农业能够协调当地生物多样性保护和实现农业可持续发展。     

大型石油罐区风险评价方法探讨

本文阐述了石油罐区风险评价的必要性，并利用适当的方法对所研究的罐区进行了安全评价。     

畜牧场污染治理排污现状及其防治对策

文章总结了上海大中型畜禽物场现有污染治理方式主要是工程治理和还田，主要手段有产沼、沉淀、曝气、厌氧发酵、好氧发酵和氧化塘（沟）等。现有治理设施正常运行率为66.7%。CODcrBOD5和NH3-N超标率分别为66.7%、58.3%和66.7%。沉淀池一氧化塘法对污染物具有较高的削减率。畜禽污染治理应向系统化方向发展。     

中国猪的优良种性及其对世界养猪业的贡献

中国养猪业有着悠久的历史，早在距今约９０００－６０００年前，中国先民们即已驯养了当地的野猪，中国古代人民十分重视猪种的选育工作，因而中国猪种的优良种性，早在汉代就驰名海内外了。汉代华南小耳猪被大泰国（罗马帝国）所引入，遂育成了古代罗马猪（又名拿波利坦猪）。迨至１７、１８世纪，中国猪（广东猪种）复被英、美等国所引入，对当时各该国猪种的改良，又起了很大的作用。近年以来，一些畜牧业发达的国家，在世界猪种资源日感贪乏的今天，特别重视引进繁殖力高的中国猪以改进西方国家猪种中母猪的生产力，并由此获得了令人瞩目的改良效果。因此，法、英、日、荷等国纷纷进行试验研究，希望能对世界猪种的改良，再度做出重要的贡献。中国猪的优良种性及其相适应的选种、饲养、管理技术，已为各国所瞩目，并且成为世界各国珍视的财富。我们能拥有如此丰富的宝贵遗产，应引以自豪。     

猪粪和锯末联合堆肥的中试研究

以 3种配比的猪粪和锯末为原料 ,进行了联合堆肥中试研究。一次发酵采用温度反馈通气量控制的静态好氧堆肥系统 ,周期 1 5d ;二次发酵采用定期翻堆自然腐熟 ,周期 30d。试验分析了堆制过程中温度、含水率、有机质、pH值的变化。对堆肥产物的腐熟度和养分分析表明 ,3种配比的堆肥产物均可达到腐熟度要求。猪粪养分含量越高 ,产物养分越高。通过堆肥工艺的优化控制和加水措施 ,猪粪和锯末联合堆制可以在 4 5d内获得高质量的有机肥 ,具有良好的应用前景。     

康集生态农场小气候的改善

本文采用对比分析的方法，分别对康集生态农场种植园、苗圃地和对照废窑地的主要小气候指标进行了观测分析。结果表明，农场种植园的建立有利于提高生长初期的日平均气温，增加干燥季节的空气相对湿度，明显降低各时期的地面最高温度和大风季节的风速，对农场局部小气候改善起了一定的作用。     

起伏地形清管过程中管内流动状态研究

目的以中原丘陵地带某天然气管道清管过程为依据,针对起伏地形清管过程中的管内流动状态变化,明确天然气清管过程中的管内流型变化,并根据积液量提出清管时间。方法通过OLGA软件揭示清管过程中管内流动参数的变化过程,并提出相应的清管周期。结果清管器在上行过程中会导致入口处的压力和温度略有增大,而越过高点时,速度迅速增大,引起入口压力和温度迅速下降,当达到最低点时,清管器前积液量达到最大值。同时出口处出液速率与清管器运行时间呈幂指数增大,通过积分可得出总出液量为333m~3,与实际结果相吻合。对于天然气管线来说,对管内积液量影响最大的因素为气相流速,其次为起伏角度,最后为液相流速。结论由于清管后天然气稳定运行60天后管内积液量达到最大值,因此建议在20天积液量为100 m~3时进行清管,同时设计末端容器体积裕量为1.2。