果梅引种初报

果梅属蔷薇科李属.果实富含有机酸,营养丰富,有“健康食品”之称 为国内外畅销果品.经济栽培大多分布在常绿果树地区.为开发丘陵山区,调整现有林种结构,增加农户经济收入,溧水县于1984年春首次引种果梅建园,目前已发展到5000余亩.现将引种结果初报如下:一、试验地概况溧水县年平均温度15.5℃,1月份平均温度2.1℃,7月份平均温度28.4℃,2月下旬和3月上旬的平均温度分别为5.2℃和7.0℃.年降雨量1036.9毫米,相对湿度79%,日照总时数2168.1小时,属中亚热带和北亚热带的过渡地区.引种试验地位于渔歌乡傅家边行政村林场,立地系西南向缓坡黄棕壤,表土层厚80厘米左右,有机质含量1.04%.     

欧洲经济共同体鸡肉、鸡蛋的生产、贸易和消费动向

欧洲经济共同体(EEC)10个国家的鸡肉生产增长缓慢;由于多数成员国鸡蛋消费下降,使蛋的生产难以进展。鸡蛋的生产 EEC的鸡蛋生产面临生产性能不断改进而国内蛋需求量下降的困难。产蛋鸡数目在减少,而蛋产量下降却不明显(表1)。因此,大多数生产单     

犬细小病毒性肠炎的诊断

犬细小病毒(CPV)性肠炎是犬的一种以急性出血性肠炎或急性心肌炎为主要表现的传染病.1976年以来.在吉林省延边地区传播,发病以初春和初冬两季为主。据其临床症状,病理解剖学及组织学变化、幼犬感染试验、HA和HI试验及病毒观察结果.确诊为犬细小病毒性肠炎。     

中蜂在春季多大的群势造脾快

春季多大的群势造脾快?这对科学饲养中蜂是有现实意义的问题。固然3框以下的弱群能造脾,这样的群势不但速度慢,而且消耗饲料相对地多;用8框以上的强群造脾,春季多有分蜂情绪,对巢础接受慢,甚至不接受。     

芒硝可提高蛋鸡生产性能

芒硝是兽医常用的一种泻下药,又称为硫酸钠(Na_2SO_4·10H_2O)。据一些资料记载,芒硝中的硫(S)促进含硫氨基酸、肝脏内蛋白质和核酸的生物合成,使器官中的硫基和谷胱苷肽含量增加,刺激体内的代谢过程,提高产蛋率,改善蛋的品质。同时,芒硝还参与牛磺酸的合成,其中的35S集中包含在蛋白质成分内,尤其多在蛋壳膜的卵角蛋白中,并增加输卵管组织中粘多糖类的生物合成。此外,芒硝能与有害物质酚形成轭     

保护地二氧化碳气体变化规律与调控

保护地二氧化碳气体变化规律与调控范开业，姚富国，林同学，周建全（山东省临沂市农业局经作站）深冬，早春在保护地内进行蔬菜的栽培．对供应淡季市场，丰富城乡“菜篮子”有着显著的经济效益和社会效益。但是此时外界气温低，为保温保护设施处于密闭状态，引起棚内二氧...     

京郊农田防护林景观生态评价--以北京大兴县北藏乡为例

Based on theories of protective forests and landscape ecology, the reasonableness of structures and patterns of shelterbelt system at Beizang Town, Daxing County, Beijing were analyzed and assessed from the two scales of forest belts and networks, by integrating uses of field investigation, GIS and RS techniques. Results showed that the existent main belt (3-12 m in width) was too narrow, while the assistant belt (3-27.1 m in width) was too wide; the species composition of the existent shelterbelts was single, and the structures and patterns of the shelterbelt system were unreasonable. It is suggested that the structure of the main and the assistant belts should be changed, such as increasing the width of main belts, decreasing the width of assistant belt, and planting more mixed species, and the pattern with arbores in the middle and shrubs in the sides of belts could be taken into account. For the landscape structure of forest network after regenerating or reconstruction, the grid number of closed network should be 13 per km2 and the minimum number of belts should be 34 per km2, This study also testified that integrating GIS and remote technique with landscape ecology could provide an effective method for reasonable reconstruction of the structures and patterns of shelterbelts system.