白菜-辣椒轮作中磷肥的产量效应及土壤磷积累研究

 采用田间肥料定位试验研究了白菜—辣椒轮作中磷肥在蔬菜上的产量效应、土壤中磷的积累状况及磷肥的经济安全用量等。结果表明，施用磷肥显著增加了白菜和辣椒的产量，磷肥在白菜和辣椒上的产量效应符合二次式＋平台模式，磷肥在白菜和辣椒上最高产量用量为186.71 kg•hm-2, 339.00 kg•hm-2。随磷用量的增加白菜和辣椒的植株全磷量、0～20cm土壤全磷及Olsen-P均显著增加，大量施用磷肥导致蔬菜对磷的奢侈吸收。磷肥在白菜和辣椒上的经济安全用量不宜超过112.5 kg•hm-2和225.0 kg•hm-2。连续2茬施用P 450.0 kg•hm-2、675.0 kg•hm-2的土壤上种植白菜，施用磷肥无显著增产效应。     

Perception and acceptance of agricultural production in and on urban buildings (ZFarming): a qualitative study from Berlin,Germany

Rooftop gardens, rooftop greenhouses and indoor farms (defined as ZFarming) have been established or planned by activists and private companies in Berlin. These projects promise to produce a range of goods that could have positive impacts on the urban setting but also carry a number of risks and uncertainties. In this early innovation phase, the relevant stakeholders’ perceptions and social acceptance of ZFarming represent important preconditions for success or failure of the further diffusion of this practice. We used the framework of acceptance to investigate the stakeholders’ attitudes and to identify the key factors that might hinder or promote the introduction of ZFarming. The results are based on an analysis of 38 qualitative interviews conducted with key stakeholders in Berlin. As the results show, major perceived benefits of ZFarming include improved consumer awareness, education, and the creation of experimental spaces. Stakeholders further perceive opportunities for resource savings, new business models, repurposing of abandoned buildings and improved aesthetics. Major perceived risks are associated with growing techniques that are considered “unnatural”, health risks (due to urban pollutants), conflicts with images of traditional agriculture, the rejection of animal production in urban areas, the risk of projects being too expensive and too complex or being implemented too early, i.e. before the mechanisms are fully understood. The analysis further reveals which contextual factors—political, legal, market-related, spatial or societal—might negatively or positively influence ZFarming acceptance.     

Cyclic adenosine monphosphate, metabolites, and phosphorylase in neural tissue: a comparison a methods of fixation

Fixation of rat brain tissue by freeze-blowing, microwave irradiation, immersion of whole rats in liquid nitrogen, and decapitation into liquid nitrogen indicates that postmortem changes in metabolites and enzyme forms are minimal in freeze-blown brains. Cyclic adenosine monophosphate levels are lowest in microwave-irradiated brains, which has been interpreted by some investigators to indicate rapid fixation and minimal anoxia. However, the changes in phosphocreatine, adenosine triphosphate, lactate, and phosphorylase clearly demonstrate that fixation by freeze-blowing or immersion in liquid nitrogen more closely approximate the state in vivo.     

Immunoglobulin M and secretory immunoglobulin A: presence of a common polypeptide chain different from light chains

Unique polypeptide chains have been isolated from S-sulfonated light-chain fractions of human serum immunoglobulin M and colostral immunoglobulin A. Their electrophoretic mobilities, molecular weights, peptide maps, amino acid compositions, and antigenic determinants are very similar or perhaps identical but differ from those of light chains and secretory piece.     

优势供给视角下乡村文化振兴路径及其内在逻辑——以福建省永春县社区大学为表达对象

乡村振兴背景下,优势供给是理解乡村文化振兴的一条新型驱动路径。构建优势供给分析视角,通过对永春县社区大学实证研究发现:优势供给作为不同于外部嵌入、内生驱动的复合型路径,具有文化内容有效、供给成本低、群众参与度高的可持续发展优势。优势供给驱动乡村文化振兴的内在逻辑在于内容的在地化、专业化与创新化契合了文化建设的有效性,供给主体的一核多元化契合了文化建设的自主性,供给成本的共担性契合了文化建设的可持续性。在今后的乡村文化振兴实践中,要注重引入主题视角。在供给内容、供给主体、供给方式层面,要坚持在党的引领下,发挥多元主体的合力,按照谁占有优势就由谁补位的原则,真正以最低成本,实现文化建设效能最大化。     

Mapping water status based on aerial thermal imagery: comparison of methodologies for upscaling from a single leaf to commercial fields

Aerial thermal remote sensing can provide a means for collecting spatial plant water status data. Many studies have shown their potential in irrigation management but the adaptation of this technology is not straight forward. In this paper, knowledge accumulated in recent years on thermal imagery analysis methodology for water status mapping is summarized aiming at indicating alternatives to calculate the Crop Water Stress Index (CWSI) for commercial scale water status mapping. Based on literature overview, four forms of wet-baselines to calculate CWSI were selected, namely: artificial wet reference surface, two theoretical calculations and a statistical bio-indicator. These baselines were used to calculate CWSI based on multi-temporal aerial thermal images of cotton fields. CWSI based on a statistical bio-indicator and one of the theoretical wet-baselines provided the best correlations. It is argued though that the statistical one is preferable since it includes the plant characteristics and it is farmer-friendly. Based on bio-indicators, leaf water potential maps of three commercial fields were produced on several dates through the season. Water status spatial patterns were not static and the effect of static factors like sandy soil patches also changed through the season. The maps show the importance of in-season variability mapping for rational irrigation management. To improve current variable-rate irrigation, the concept of in-season irrigation management zones (IMZ) based on thermal-images should be considered and integrated with the delineation of static irrigation IMZ.     

Processing of remote sensing information to retrieve leaf area index in barley: a comparison of methods

Precision Agriculture - Leaf area index (LAI) is a key variable in understanding and modeling crop-environment interactions. With the advent of increasingly higher spatial resolution satellites and...     

A Bayesian network to predict the probability of organic farms’ exit from the sector: A case study from Marche, Italy

The maintenance of organic farming production schemes is a theme receiving a growing interest now that there are signs of a slowing in organic farming uptake in Italy. The present study develops a model based on a Bayesian network (BN) that is aimed at investigating the factors that affect the exit of a farm from the organic sector and to simulate the probability of maintaining an organic scheme for different farm types. The model is based on a database of organic farms, which has been integrated with qualitative information. Farm-type simulation and sensitivity analysis of most of the relevant variables have been carried out. Main results show that arable farm types are those with a higher probability to stay in the organic sector, while farmers’ age, Province the farm is situated in and farm size are the factors mostly influencing probability scores.     

新疆石榴树害螨:如今细须螨—中国新纪录

【目的】叶螨是一类重要的农业有害生物,近年来在新疆喀什地区石榴害螨危害呈上升趋势,严重制约该地区石榴产业的可持续健康发展。调查新疆喀什市周边石榴产区,采集石榴树优势种害螨标本,鉴定种类,为该螨生物学、生态学特性研究打基础。【方法】利用吸虫管、微小虫分离器、镊子、解剖针、毛笔、叶螨保存液等工具,采用小毛笔蘸液直接黏取法、敲打振落法手段采集害螨标本。【结果】通过采集鉴定新疆喀什市周边石榴树害螨为如今细须螨(Tenuipalpus hornotinus Chaudhri,1971)中国新记录种,描述了该螨种区别其它近似种鉴别特征及形态特征。【结论】该种12♀螨,2008年采自新疆喀什市阿瓦提乡石榴树上。     

Climate and vegetation history of the midcontinent from 75 to 25 ka: A speleothem record from crevice cave, missouri, USA

Four Missouri stalagmites yield consistent overlapping records of oxygen and carbon isotopic changes and provide a climate and vegetation history with submillennial resolution from 75 to 25 thousand years ago (ka). The thorium-230-dated records reveal that between 75 and 55 ka, the midcontinental climate oscillated on millennial time scales between cold and warm, and vegetation alternated among forest, savanna, and prairie. Temperatures were highest and prairie vegetation peaked between 59 and 55 ka. Climate cooled and forest replaced grassland at 55 ka, when global ice sheets began to build during the early part of Marine Oxygen Isotope Stage 3.