Effects of shifting cultivation on biological and biochemical characteristics of soil microorganisms

来源 :Journal of Forestry Research | 被引量 : 0次 | 上传用户:bbxxxb
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
We collected soil samples from two representative sites at Aatmile of Khagarachari hill district in Chittagong Hill Tracts. One of the sites was under shifting cultivation and the other an adjacent 13-year old teak plantation. Both sites were in the same physiographic condition and same aspect with parable soil type, which enabled us to measure the effects of shifting cultivation on soil micro-flora. We studied soil physico-chemical properties and the biochemical and biological properties of soil microbes. Moisture and organic matter content as well as fungi and bacterial populations, both in surface and subsurface soils, were significantly(p ≤0.001) lower in shifting cultivated soils compared to soils not under shifting cultivation, i.e. the teak plantation site. The most abundant bacteria in surface(0-10 cm) and sub-surface(10-20 cm) soils under shifting cultivation were Pseudomonas diminuta and Shigella, respectively, while in corresponding soil layers of teak plantation, predominant microbes were Bacillus firmus(0-10 cm) and Xanthomonas(10-20 cm). The microbial population differences cannot be explained by soil texture differences because of the textural similarity in soils from the two sites but could be related to the significantly lower moisture and organic matter contents in soils under shifting cultivation. We collected soil samples from two representative sites at Aatmile of Khagarachari hill district in Chittagong Hill Tracts. One of the sites was under shifting cultivation and the other an adjacent 13-year old teak plantation. Both sites were in the same physiographic condition and same aspect with parable soil type, which enabled us to measure the effects of shifting cultivation on soil micro-flora. We studied soil physico-chemical properties and the biochemical and biological properties of soil microbes. Moisture and organic matter content as well as fungi and bacterial populations , both in surface and subsurface soils, were significantly (p ≤ 0.001) lower in shifting cultivated soils compared to soils not under shifting cultivation, ie the teak plantation site. The most abundant bacteria in surfaces (0-10 cm) and sub-surfaces (10-20 cm) soils under shifting cultivation were Pseudomonas diminuta and Shigella, respectively, while in corresponding soil layers of teak plantation, predomin The microbes were Bacillus firmus (0-10 cm) and Xanthomonas (10-20 cm). The microbial population differences can not be explained by soil texture differences because of the textural similarity in soils from the two sites but could be related to the significantly lower moisture and organic matter contents in soils under shifting cultivation.
其他文献
新闻1月23日,国务院办公厅发布了国务院关于印发能源发展“十二五”规划的通知。至此,讨论多时的《能源发展“十二五”规划》终于尘埃落定。尽管之前曾经出台过征求意见稿,但
这些年来,探讨生活方式的书越来越多了,有妙悟人生的,有潇洒人生的,有闲适人生的,甚至有无聊人生的,而亨利·戴维·梭罗,则可以称之为实验人生的。亨利·戴维·梭罗(1817-186
本方案适用于市区临城市干道(道南和道北)。 1.户室类型: 考虑了二室户、三室户两种户空类型,没有考虑一室户,因为一室户是不稳定户,也未考虑四室户。二室户占的比例数大,无
一、膨胀螺栓特性简介膨胀螺栓通过螺杆和套筒的开尾,传递挤压应力实现对工件的紧固。开始仅应用于建筑中的室内镶板(天花板、吸音板)、水槽、水箱、吊灯、配电箱、开关、油
英国发明了一种新方法,用以在现场修补损坏了的混凝土、岩石和其它砌体。这种方法采用真空法把硅烷材料注入混凝土或脆性的岩石里去,这样使之结实牢固,能够抗风雨。混凝土路
从旧金山、洛杉矶到华盛顿、纽约、芝加哥的考察见闻冲击着感官,收获虽多却浮光掠影,难以成文!下面仅就建筑材料方面谈几点感受。 国外建筑师对建筑材料的使用可以用“浓妆
研究了采用电化学方法抛光粉末冶金异形模具的工艺参数、电解液的组成和配比。用轴承钢(GCr15)做的模具,抛光后可使其粗糙度Ra值从2.4~1.6降到0.8~0.4,其尺寸精度可控制在0.015
马克思在论述剩余价值理论时说过:真正的财富就在于用尽量少的劳动时间创造出尽量丰富的物质财富。经营与管理的目的和实质,就在于用尽量少的人力、物力、财力和时间的消耗,
比较了钢筋混凝土带支撑框架与带暗支撑剪力墙的抗震性能,给出了它们抗震承载力的计算公式,提出了供抗震设计参考的建议. The seismic performance of the RC frame with suppo
随着社会的发展,建筑行业竞争越来越激烈。为了能够更好的生存,进一步提高施工管理的水平非常重要,从而能够在很大程度上提升企业的竞争力。然而,施工管理是一项系统的工作,