土壤团聚体有机碳研究进展

土壤有机碳是衡量土壤肥力的重要指标,对于促进土壤养分循环、增加养分有效性有重要作用。土壤团聚体是土壤的重要组成部分,是组成土壤结构的最小单元,受到自然因素和人为因素的影响,其形成转化过程与土壤固碳过程息息相关,因而研究团聚体和有机碳的关系及团聚体有机碳影响因素对于土壤结构的改善和土壤质量的提升具有重要意义。本文通过对文献的总结,明晰了土壤团聚体和有机碳的关系,阐述了土壤类型、施肥方式、土地利用和矿区复垦对土壤团聚体有机碳的影响,并从生物质炭的长期定位研究和复垦矿区的土壤修复两方面对土壤团聚体有机碳的研究进行展望,研究结果可为合理的农业生产提供科学依据。     

Impact of grassland contract policy on soil organic carbon losses from alpine grassland on the Qinghai–Tibetan Plateau

Carbon storage in the soils on the Qinghai–Tibetan Plateau plays a very important role in the global carbon budget. In the 1990s, a policy of contracting collective grasslands to smaller units was implemented, resulting in a change from the traditional collective grassland management to two new management patterns: a multi‐household management pattern (MMP: grassland shared by several households without enclosures) and a single‐household management pattern (SMP: grassland enclosed and used by only one household). In 2016, 50 MMP and 54 SMP winter pastures on the Qinghai–Tibetan Plateau were sampled to assess the differences in soil organic carbon (SOC) between the two management patterns. Results showed that average SOC was significantly greater under MMP than under SMP, with an estimated 0.41 Mg C/ha/yr lost due to SMP following the new grassland contract. Based on the government's grassland policy, four grassland utilization scenarios were developed for both summer and winter pastures. We found that if the grassland were managed under SMP, likely C losses ranged between 0.31 × 10⁷ and 6.15 × 10⁷ Mg C/yr across the Qinghai–Tibetan Plateau relative to MMP, which more closely resembles pre‐1990s grassland management. Previous estimates of C losses have only considered land use change (with cover change) and ignored the impacts driven by land management pattern changes (without cover change). The new data suggest that C losses from the Qinghai–Tibetan Plateau are greater than previously estimated, and therefore that the grassland contract policy should be reviewed and SMP households should be encouraged to reunite into the MMP. These findings have potential implications for land management strategies not only on the Qinghai–Tibetan Plateau but also other grazing regions globally where such practices may exist.     

智慧图书馆微观知识生态系统运行机理研究

伴随多元化时代的来临,用户的知识需求日益多元化、专业化,对图书馆服务提出了新的挑战。对智慧图书馆微观知识生态系统运行机理的研究,能够为新型知识服务提供理论基础,保障知识资源进行有效的优化整合,实现服务升级。文章在简要分析智慧图书馆微观知识生态系统四大要素的基础上,着重从社会发展、技术进步,知识富集、优化调整和需求驱动、服务升级三方面探讨其形成动因,重点分析智慧图书馆微观知识生态系统的生命周期,最后从合作、循环和保障三方面探讨其运行机理。     

岭西电网经济分析

本文对岭西电网的经济运行调整进行了分析、总结。并应用《岭西电网经济运行计算》系统的计算结果，提出了岭西电网的经济运行调整办法。     

搞好水土保持 造福子孙万代

搞好水土保持造福子孙万代肖作福（辽宁省人民政府，沈阳１１００３２）从５０年代初期，辽宁省开始了水土保持工作的征程，现已走过四十多年的历程。辽宁人民在辽宁大地上，奋斗不息，重新描绘着山河面貌，谱写了水土保持工作的新篇章。辽宁省的自然状况是“六山一水三分...     

水土保持是山丘区经济发展的根本出路

水土保持是山丘区经济发展的根本出路肖秧（四川省人民政府，成都６１００００）四川地处长江上游，幅员辽阔，境内高山峻岭，江河纵横，是一个有一亿多人口的农业大省。由于历史原因，森林曾遭严重破坏，加之人口众多，人均耕地数量少，垦殖指数高，水土流失十分严重。遥...     

我国农村经济组织体系分析

通过分析我国现阶段农村经济组织的组织模式、功能及组织连接机制,指出我国农村经济组织已形成以农户家庭经营为基础层次,以社区合作经济组织、专业合作经济组织及以“公司 农户”为典型的契约型组织分别为第二、三、四层次,效能逐级递增,各层次之间具有互动作用的组织体系。     

振动深松鼠道犁的试验分析

石河子及周围垦区的土壤粘重且呈盐碱性,由于犁底层的存在,土质很难得到改善。而深松作业则是打破犁底层的主要农业技术措施之一。为此,论述了IZSS-600-3型振动深松鼠道犁的构造和工作原理,分析了试验因素对试验指标的影响,为机具今后在农业生产中的应用和推广提供了依据和参考。     

火鸡隐孢子虫在鹌鹑体内发育史的研究

分离自鹌鹑的火鸡隐孢子虫经口感染２日龄鹌鹑，潜在期为３ｄ，开放期为４－１８ｄ。它在鹌鹑体内发育史过程为：卵巢经口接种后，于十二指肠，空肠，回肠肠腔中子孢子脱囊，至接种后６ｈ全部子孢子脱囊完毕。接种后６ｈ在小肠中出现滋养体。接种后１２ｈ在小肠中出现内含８个裂殖子的裂殖体及裂殖子，接种后４８ｈ滋养体和裂殖体开始出现于直肠。接种后５４ｈ，在小肠，直扬中出现含有１６个子弹形小配子的小配子体。小配子与大配子