平衡施肥对黑麦草生长及产量的影响

NPK平衡施用具有明显促进黑麦草生长的作用。农民习惯施肥的产量比不施肥提高25．3％，但远低于NKP平衡施肥处理，习惯施肥的产量仅为平衡施肥的41％，NPK配合施用的产量是不施肥处理的3倍。黑麦草施用磷、钾肥均有明显增产效果，其中磷肥效果大于钾肥，钾肥在生长后期的增产效果大于前期。不同施肥处理的经济效益差别很大，农民习惯施肥和单施N肥的增收效果非常有限，NPK配合施用增加纯利润达3383元／hm^2，其次是NP配合增加纯利润2720元／hm^2。     

化肥养鱼八注意

１施用化肥前，最好先施有机肥料，继而两者配合使用，这样方能使鱼塘中的肥效持久稳定，促使浮游生物持续繁殖。２施用化肥的时间以每年５～７月和９～１０月为宜，以晴天中午，水温２０～３０℃时为佳。３施颗粒状化肥时均应先溶于水，然后混合均匀再全池泼洒。切忌为图省事将固体化肥直接撒入鱼塘中，鱼误食而死。４施用氮肥和磷肥时，应有一定顺序，先施氮肥，后施磷肥，不能颠倒和同时进行。并切忌与石灰、草木灰和其他碱性肥料混合施用。５氮、磷、钾肥要合理搭配，一般认为氮、磷、钾以２：２：１繁殖浮游生物效果较好。６施化肥应注…     

化肥养鱼技术

化肥养鱼具有运输方便,施用简单,养分含量高,不含有机质,不消耗水中氧气,不污染水体,见效快,效益高等优点。一般情况下,施尿素1公斤,可长成鱼1.5公斤;施硫酸铵1公斤,可长成鱼0.5—0.6公斤、0.7公斤;施磷酸铵1公斤,可长成鱼0.5公斤;施碳酸氢铵1公斤,可长成鱼0.5～0.6公斤;施氨水1公斤,可长成鱼0.1公斤。 施放氮素化肥养鱼时有下列问题应当注意: 1、氮素化肥虽然含氮量高,但成分单一,属不完全肥料,必须混施磷、钾肥,混施比例为2:2:1。淤泥较多的池塘,可不施钾肥。 2、施用氮素化肥前,最好先施有机肥料作基     

苏丹草的刈割和管理技术

苏丹草是当前季节草食性鱼(主要是草鱼、鳊鱼)的主要青饲料。如何提高苏丹草的产量和质量，对提高草食性鱼的产量和提高苏丹草的利用率关系重大，在目前已成苗的情况下。适时，正确地刹割和科学地管理是提高苏丹草产量和质量的关键。     

精养鱼塘施化肥“十忌”

施化肥养鱼是提高鱼产量的有效措施之一,也是我国传统养鱼方式中重要技术措施之一。它对提高鱼产量十分有效,具有施用简单,不污染水质,减少鱼病的发生及外来病源的入侵,人力物力消耗少,见效快的特点,因此在精养鱼塘中,化肥被广泛应用于成鱼养殖、鱼苗鱼种培育。今年5—9月,我们实行了化肥养殖成鱼和鱼种培育试(实)验,取得了明显的收     

绿肥在鲢、鳙为主体混养池塘中的养鱼效果

在鲢、鳙为主体鱼的混养池塘中,分别施用4种绿肥,试验结果,获得每天每公顷19.59到25.33千克的鱼产量.4种绿肥以苏丹草新鲜堆放法效果为佳,鱼产量较高。     

养鱼池塘切忌缺磷

<正> 池塘施肥是提高鱼产量的重要措施。但是,近几年来.有些养鱼户在施肥时只施氮肥,不施磷肥,造成池塘严重缺磷。因此,池塘虽然施肥不少,但是效果却不太明显,其主要原因就是营养单一。现将磷肥的作用和施用方法介绍如下:1 磷肥的作用 施肥的目的是培育大量的浮游     

泉上水库施用化肥养鱼试验

总结了泉上水库2002～2004年施用化肥养鱼情况，通过施化肥等措施，鱼产量、渔业效益大幅提高；2002～2004年收成鱼13．32万尾，成活率达57．9％，鱼产量151．45吨，年平增产63.3吨；总产值68．83万元，纯收入20．51万元，投入与产出比为1：1．42。     

鱼塘施肥与水质调节

养鱼池塘施肥是繁育浮游生物,提高鱼产量的有效措施之一。施肥要讲究科学。特别要讲究“好”和“巧”两个字。“好”,就是鱼肥投施得不迟不早,恰到好处。“巧”,就是要效果好,利用率高,事半功倍。下面,就这个问题,我谈谈自己的一点看法,供广大读者参考。一、巧施鱼肥夏天:由于水温高,鱼活动力强,摄食旺盛。鱼池应多施化肥。化肥肥效快,在短时间内,能使鱼池中浮游生物大量地繁殖起来。施用化肥时,除注意施肥量     

水库三种养鱼方式效益比较试验研究

在水库中开展网箱带大库养鱼，投草养鱼和施化肥养鱼试验，并进行效益对比分析，参试水库１８座，面积２９０．２ｈａ。大库单产成鱼９８７ｋｇ／ｈａ，盈利１．６６元／ｋｇ，投入产出比为１：１．７４。对比结果表明：投入产出比和千克鱼盈利以网箱带大库养鱼方式最佳，单位面积的产量、产值，盈利，施化肥养鱼和投草养鱼指标基本接近，网箱带大库养鱼次之。     

Esophagoscopy and gastroscopy in dogs and cats. Technics and indications

A report is presented of esophagoscopy and gastroscopy in cats and dogs using flexible endoscopes. Following consideration of the basic equipment, an account is given of patient preparation and anesthesia, topography, investigation technique and normal findings. Diagnostic potential, indications and risks involved are discussed.     

虾蟹血淋巴的抽取与固定

随着人们对甲壳动物生理生态学研究的逐步深入,尤其是与免疫应答密切联系的血液生理学领域被广泛关注.抽取和固定血淋巴,成为进行血液学研究必不可少的步骤.那么如何更好地抽取和固定血淋巴呢,本文以虾蟹为例做了总结,以供参考.     

中国鲟鱼的保护、管理与产业化

1　世界现存鲟鱼的种类和资源鲟鱼是一类起源早、具有重要科学研究价值和极高经济价值的稀有物种 ,多数种类个体大 ,半数种为溯河洄游产卵鱼类。按目前较为公认的分类系统 ,现存鲟鱼类有 2科 6属 2 7个种 ,隶属于硬骨鱼纲、软骨硬鳞总目、鲟形目 (Acipenseriformes) ,其中鲟属有 17个种 ,主要经济种类在其中。它们全部分布于北半球 ,现存 9个自然分布区为 :太平洋东岸、北美大湖地区、大西洋西北部、北美密西西比河流域和墨西哥湾、大西洋东北部、里海地区、西伯利亚及北冰洋流域、黑龙江和日本海、长江和珠江。鲟鱼自然种群资源稀少 ,在过…     

Achieving sustainable aquaculture: Historical and current perspectives and future needs and challenges

Important operational changes that have gradually been assimilated and new approaches that are developing as part of the movement toward sustainable intensive aquaculture production systems are presented via historical, current, and future perspectives. Improved environmental and economic sustainability based on increased efficiency of production continues to be realized. As a result, aquaculture continues to reduce its carbon footprint through reduced greenhouse gas emissions. Reduced use of freshwater and land resources per unit of production, improved feed management practices as well as increased knowledge of nutrient requirements, effective feed ingredients and additives, domestication of species, and new farming practices are now being applied or evaluated. Successful expansion into culture of marine species, both off and on shore, offers the potential of substantial increases in sustainable intensive aquaculture production combined with integrative efforts to increase efficiency will principally contribute to satisfying the increasing global demand for protein and food security needs.     

Food habits and growth of silver and bighead carp in cages and ponds

Analysis of intestinal contents of silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis) showed that silver carp consumed primarily phytoplankton while bighead carp consumed large quantities of zooplankton and detritus in addition to phytoplankton. The size of particles filtered by the bighead carp was larger (17–3,000 μm) than that filtered by silver carp (8–100 μm). Artificial feed was readily consumed by bighead carp but not by silver carp. No growth difference was indicated for silver carp in fertilized ponds and ponds receiving artificial feed. Growth of bighead carp increased substantially with the addition of artificial feed. Silver carp grew more rapidly in cages than bighead carp.     

虾蟹专用肥的研究开发及应用

20 0 1年 ,江苏省高邮市农林局与中国水产科学研究院淡水渔业研究中心及扬州市春申生物化工有限公司共同承担了江苏省水产更新工程项目———“虾、蟹专用肥料的开发研究与推广”。经项目组人员的共同努力 ,现已顺利完成项目任务 ,研究开发的虾、蟹专用肥在试用和大面积推广应用中取得了显著效果。虾、蟹专用肥已被列为江苏省第一批无公害水产品基地拟用鱼药、饲料推荐产品 ;也是江苏省水产技术推广站、安徽省水产技术推广站、江苏省高邮市农林局、江苏省兴化市水产局、江苏省宝应县水产局、安徽寿县水产局等十多个水产行政主管和技术推广部…     

Fish assemblage associations and thresholds with existing and projected oil and gas development

Energy development threatens fish and wildlife resources worldwide. This study used constrained ordinations to show fish assemblage structure associated with oil and gas well densities in the Colorado River Basin, Wyoming, but well densities explained only 6.4% of assemblage structure when compared to other factors. Threshold Indicator Taxonomic ANalysis showed significant negative threshold responses by some species to small levels of development (<0.15 wells km^?2), whereas positive thresholds were less distinct. Some native and imperilled species could be disproportionately affected if future oil and gas development proceeds in a manner that will impact aquatic resources. Although existing development has not substantially influenced regional fish assemblage structure, it appears to affect a subset of species. Understanding assemblage‐level responses to development can help land managers determine appropriate development levels, prioritise areas for monitoring associated with future development and identify where land protection measures may be needed to offset potential risks.     

Gar biology and culture: status and prospects

Many lepisosteid populations in North America have declined and many are now threatened as a consequence of habitat loss and alteration and commercial and sport overfishing. Over the last two decades, morphological, histological and molecular studies allowed distinguishing between different phases of development and the nutritional condition of larvae. Ontogeny of the digestive enzymes of gar larvae indicated the possibility to feed them artificial feeds since early developmental stages. An in vitro digestibility system to test different feed ingredients has been used. Important characteristics of artificial diets were identified through different feeding experiments. Endocrinological studies showed the feasibility of altering larval development and the digestive capacity of larvae. Cloning of gar growth hormone opened new avenues to enhance growth in the gars. Plasmatic vitellogenin was isolated and purified, to develop a competitive enzyme‐linked immunosorbent assay, which allowed the straightforward separation of males from females to establish appropriate proportions for reproduction and also was used to evaluate hormonal protocols to induce gonad recrudescence and spawning. This review analyzes the biology, ecology and physiology of different gar species as a basis for their domestication, mass production of larvae for repopulation experiments and for the culture of commercial‐size gar.     

加快城乡统筹,推进我国农垦体制创新与经济发展的研究与思考

"十一五"以来,我国农垦加快体制机制改革、结构调整和经济增长方式的转变的步伐,参与市场竞争,努力提升企业和产品竞争力,经济社会事业发展较快,对国家的贡献提升,职工收入、生活质量明显提高和改善,示范引领作用不断增强.本文针对农垦体制机制创新进展滞缓,战略定位与发展方向不明,经济增长方式转变和结构调整缺乏资本、人才、技术的支撑,没有处理好改革、发展、稳定、民生的关系,投资匮乏,发展后劲不足,人才短缺和劳动力素质低下的现状,提出在未来农垦体制机制创新中要特别关注改革方向、目标设定与评估,改革要在现行法律法规的框架内运作,改革时机的选择,处理好改革发展稳定与民生的关系,调整好内部利益分配关系,自觉融入区域经济,与地方协同发展等问题.为了促进农垦的发展,建议国家加大对农垦体制机制创新、现代农业建设、国有农场土地资源的保护、社会保障体系的完善等财政和政策的支持力度.