西安失地农民就业安置研究

西安失地农民就业意愿不够强烈,就业转移和安置情况不容乐观。农民素质阻碍了再就业,就业意识与市场要求差距较大,安置形式单一,就业情况严峻。要建立失地农民就业机制,保障就业经费,引导劳动密集产业和第三产业,加强就业信息服务和技能培训,拓展安置就业渠道,抓好自主创业工作。     

磷肥施用对水稻生长和磷素吸收的影响

采用田间微区试验研究不同磷肥的施用位置和类型对姜堰、广德两地水稻生长、磷素吸收以及施肥后地表水磷浓度的影响,为水稻根区施磷提供科学依据。磷肥种类为磷酸二氢钙(MCP)和磷酸氢二铵(DAP),施用方式有:1表面撒施;2偏3 cm,深5 cm穴施;3偏12 cm,深5 cm穴施。结果显示施磷对两地水稻均无显著增产,姜堰地区水稻产量显著高于广德。不同施磷位置对水稻吸磷量有显著影响,姜堰、广德两地MCP偏3 cm处理的水稻总吸磷量较MCP偏12 cm处理分别高13%和12%,且DAP偏12 cm处理的水稻总吸磷量显著高于MCP偏12 cm处理,两地增幅分别达到12%和16%,磷肥撒施虽然在水稻分蘖期有较高的吸磷量,但在水稻成熟期不如磷肥偏3 cm穴施。施肥第10天的地表水总磷浓度以磷肥表面撒施处理较高,比磷肥穴施处理分别高245%(姜堰)和94%(广德)。以上结果表明:1适当位置的磷肥穴施不但能够促进水稻对磷的吸收,还能有效缓解径流排水造成的磷流失;2磷酸氢二铵的磷肥适宜施用距离范围较磷酸二氢钙远。     

近30年来家属馆员安置问题浅议

回顾近30年来,谈论图书馆家属馆员的文章数量、主题分布及代表性观点、发表刊物的分布。归纳起来,这种口诛笔伐现象的4种原因为：一是劣币驱逐良币;二是女权运动的倒退;三是领导决定一切;四是专业化得不到认可。认为图书馆界今后要对家属馆员问题采取一致的措施、立场。     

施肥位置对纸筒育苗移栽甜菜的产质量影响研究

为明确当前东北甜菜生产上普遍采用的纸筒育苗移栽田肥料的合理使用方法,历经3年,在黑龙江的气候相对湿润的中东部区和相对干燥的西部区,采用田间小区试验,通过设置距离纸筒苗的横向距离和施肥深度2个变因,研究了氮磷钾三元素混合肥料不同施肥位置对纸筒育苗栽培方式下的甜菜产质量影响。结果表明：移栽时不坐水条件下,肥料施用距纸筒的横向距离越近,增产效果越好,深度10、15 cm处理效果相当,两者均比深度5 cm处理显著增产;如移栽时坐水,施肥距纸筒的横向距离选择5 cm,施肥深度10-15 cm对甜菜块根产质量最有利;无论移栽时坐水或不坐水,施肥的横向或纵向位置对甜菜块根含糖影响较小,不同处理之间差异不显著。     

浅析路侧绿带植物的选配

城市道路绿化是城市园林绿地系统的重要组成部分,也是城市文明的重要标志之一。道路绿化的主体是植物,探讨选择路侧绿带植物需要侧重的几个方面,以及如何通过合理的配置使路侧绿带植物发挥最大的生态效益,起到最佳的功能性作用和满足不同情况下的观赏需求。     

Placement effects of organic sources on nitrogenase activity and nitrogen-fixing bacteria in flooded rice soils

The placement effects of organic sources (cellulose and rice straw) at different depths on nitrogenase activity (acetylene reduction assay, ARA) associated with four tropical rice soils were investigated. Results showed that placement of organic sources in the top profile (1–2 cm) produced a higher nitrogenase activity; while placement in the 2–4 cm and 4–6cm profiles significantly decreased the activity irrespective of soil type. The effect of organic sources on nitrogenase varied depending on the soil type. Cellulose and rice straw caused differential stimulation in response to the placement. Evidence was provided for the creation of favourable redox potential supporting higher nitrogenase activity in series receiving organic amendments in the top profile. Higher nitrogenase activity in the top profile was associated with greater populations of nitrogen-fixing Azospirillum sp., anaerobic nitrogen fixers and Azotobacter sp. Moreover, the lower amounts of reducing sugars and higher carbon dioxide evolution gave evidence of higher microbial activity in the top profile. These results clearly indicate the positive relationship between nitrogenase activity, nitrogen-fixing populations and redox status in the top layers of flooded tropical rice soils. Received: 5 June 1996