流水池培育二龄草鱼种试验

每个面积约30平方米的流水池共38个,每平方米放养草鱼种38尾。采取曝气增氧、排污换水,提高流水池的溶氧量,以及投喂精料,防治鱼病的措施,获得每平方米生产二龄草鱼种15.41公斤的成绩。     

可控止回阀水力特性的测试研究

本文运用水流相似原理，对可控止回阀的流阻系数曲线和动水力矩，进行了系统的水力模型试验研究，为该阀的节能效益和技术开发的可行性，提供了必要的科学依据，其流阻系数值为０．１９，优于液控蝶阀。     

控制原虫对绵羊瘤胃内环境指标的影响

试验以绵羊为试验动物研究了控制原虫的种类和数量对瘤胃内环境指标的影响。结果表明 ,全部驱除原虫和部分驱除原虫可依次降低乙酸的摩尔浓度百分比 ,提高丙酸的摩尔浓度百分比 ,降低NGR值 ,但各处理对瘤胃内pH值的动态变化规律无明显影响 ;各组绵羊瘤胃内NH3-N浓度的高低依次是 :对照组 >部分驱组 >全驱组。     

Sediment Load in Runoff Under Laboratory and Field Simulated Rainfall

Soil erosion is one of the most important problems in the Loess Plateau of China affecting sustainable agriculture. Near Luoyang (Henan Province, China), field plots were constructed to measure soil erosion rates under conventional tillage practices using field-simulated rainfall.Field rainfall experiments were carried out to compare previous results from laboratory rainfall simulations on the same soil for interrill conditions. Although in the laboratory experiments, a strong correlation was found betweenthe stream power of the runoff water and the unit sediment load, this sediment transport equation overestimated the field rainfall simulation results. Another sediment transport equation derived by Nearing et al. for rill erosion was in better agreement with the results of the field experiments, although it also overestimated these values. The measured sediment load values during the field rainfall simulations were also lower than those found during field experiments on the same soil but with a loosened surface layer. This difference indicates the importance of soil physical condition of surfce like soil structure and aggregate size, which may contribute to the discrepancy between the field and laboratory experiment results.     

水分对硝酸磷肥中氮的扩散及其肥效的影响

国产硝酸磷肥含氮27%,磷13.5%。所含速效氮中硝态氮均占一半。研究麦田不同水分对硝酸磷肥中硝态氮在土壤中扩散结果显示,硝态氮在土壤中下移深度与土壤湿润峰的深度基本一致,在小麦越冬期有表聚现象。当灌水量为田间持水量时,硝态氮移动深度为40～50cm,是在主要根系活动层内,这对小麦吸收有利,不会产生氮的流失。等氮磷条件下,硝酸磷肥与磷铵加尿素在北方地区有同样肥效。     

红嘴鸥群发矛形剑带绦虫病

矛形剑带绦虫是家禽中一种常见的寄生虫 ,鸭鹅多发 ,笔者于动物园中曾发现一起红嘴鸥感染矛形剑带绦虫 ,极为罕见。红嘴鸥是太湖中常见的一种水禽 ,一般体重在0 .5 kg左右 ,我园曾收到个体户野外捕捉到的红嘴鸥 1 2只 ,刚来园时表现极度消瘦 ,贫血 ,羽毛蓬松 ,食欲减少或废绝 ,精神渐进性下降 ,活动少 ,飞翔无力 ,后期仅在地面上划动 ,走路摇摆无力 ,有时失去平衡而倒地 ,有些个体表现有神经症状 ,摇头 ,仰翻于地 ,双肢呈划水状 ,拉白色稀便 ,偶见粪便中有乳白色绦虫节片 ,病程 7～ 1 0天 ,病后期衰竭而死。剖检病死鸥见其心、肝、脾、肺、…     

氮肥施用"九不宜"

一是铵态氮肥不宜与碱性肥料混用。因为混施后会产生氨气，降低肥料效果。常用的铵态氮肥有碳铵、硫酸铵等，碱性肥料有草木灰、石灰等。     

大型猪场废水处理新工艺及回用农业技术通过专家验收

农业部环境保护科研监测所承担的天津市科委自然科学基金重点项目“大型猪场废水处理新工艺及回用农业技术”近期通过了天津市科委组织的专家验收。该项技术采用厌氧折流板（ABR）和改良SBR组合工艺处理猪场废水，废水处理后达到国家农田灌溉水质标准。形成一体化处理设备获得国家实用新型专利（专利号：ZL200420029270．7）。通过在宁河原种猪场进行现场小试，效果良好，得到用户肯定。该套工艺具有投资省，运行成本低，管理方便等特点。我们愿为社会上不同规模畜禽养殖场粪污的处理提供技术咨询、工艺设计和运行调试等多项技术服务。