检索结果-南通市图书馆

Dynamics of Land Use and the Evolution of Agroforestry Practices in the Dja Biosphere Reserve (DBR) Southeast Cameroon

引用

Journal of Geoscience and Environment Protection 2020年第5期8卷 346-358页

作者： Njini Loveline Munjeb Avana Tientcheu Marie Louise Julius Tata Nfor yerima bernard palmer kfuban Jean-Michel Harmand Department of Forestry Faculty of Agronomy and Agricultural Sciences (FASA) University of Dschang Dschang Cameroon Department of Geography Planning and Environment Faculty of Letters and Social Sciences University of Dschang Dschang Cam-eroon Department of Soil Sciences Faculty of Agronomy and Agricultural Sciences (FASA) University of Dschang Dschang Cameroon CIRAD/DP-Agroforestry Yaounde Cameroon

The study had as objective to investigate the land use/land cover change from 1980 to 2019 in the Dja Biosphere Reserve using GIS and remote sensing techniques and the evolution of agroforestry practices. Semi structured questionnaires were administered to 320 farmers who were randomly selected from 35 villages of the Dja Biosphere Reserve characterized by the presence of agroforestry systems. The land use map revealed six classes which were dense humid forest, perennial crop-based agroforestry practices, river, wetland, built up and bare areas. Between 1980 and 2008, dense humid forest lost -4.9% of its area to the benefits of perennial crop-based agroforestry practices, built up and bare land. Between 2008 and 2019, dense humid forest gain 1.77% of its area due to increase in perennial crop-based agroforestry practices and a subsequent increase in vegetation cover. Perennial crop-based agroforestry practices and built up increase progressively from 1980 to 2019. Farmers perceived hunting (36.3%), slash and burn agriculture (43.3%) and harvesting of tree-based products (20.3%) as the anthropogenic activities impacting the reserve negatively. The evolution of agroforestry practices were observed on the field, but the precise area under agroforestry practices in the study area need to be estimated. As a mitigation strategy to livelihood needs as well as the rehabilitation of degraded land, the conversion of pure cultivated agricultural land into agroforestry is a major opportunity.

关键词： Land Use/Land Cover GIS and Remote Sensing Techniques Agroforestry Dja Biosphere Reserve

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Influence of Clay Minerals on Some Soil Fertility Attributes: A Review

引用

Open Journal of Soil Science 2019年第9期9卷 155-188页

作者： Georges Kogge Kome Roger Kogge Enang Fritz Oben Tabi bernard palmer kfuban yerima Department of Soil Science Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang Republic of Cameroon

Clay minerals constitute an important component of the soil system and knowledge of their role in soil fertility is imperative for sustainable soil management and productivity. The aim of this work is to overview the influence of clay minerals on some major soil fertility attributes. The rationale for carrying out this work is that most soil fertility studies rarely incorporate soil mineralogy. Clay minerals, through their physical and chemical properties, affect soil fertility by controlling nutrient supplies and availability, through the sequestration and stabilization of soil organic matter, by controlling soil physical properties through microaggregate formation, by influencing soil acidity and controlling soil microbial population and activity. The main processes involved in these relationships are dissolution-precipitation and adsorption-desorption processes, alongside mechanisms involving the formation of short-range-ordered phases. Although the determination of soil mineralogical properties is very costly and time-consuming, information about a soil’s mineralogy is imperative for a holistic understanding and proper management of soil fertility. Therefore, the development of rapid, low-cost, reliable and efficient techniques of soil mineralogical analysis, directly applicable to soil fertility investigations, constitutes a major challenge. Also, future research should investigate the relationships between clay minerals and soil nitrogen vis-à-vis sequestration and stabilization. Lastly, clay minerals should be considered in studies dealing with soil quality assessment, especially in the choice of soil quality indicators.

关键词： Clay Mineralogy Nutrient Supply Ion Adsorption-Desorption Mineral Dissolution-Precipitation Nutrient Availability

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Short-Range-Order Minerals and Dominant Accessory Properties Controlling P Sorption in Tropical Tephra Soils of the Cameroon Volcanic Line

引用

Open Journal of Soil Science 2019年第8期9卷 113-139页

作者： Roger Kogge Enang bernard palmer kfuban yerima Georges Kogge Kome Eric van Ranst Soil Science Department Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang Cameroon Geology Department Faculty of Sciences Ghent University Ghent Belgium

Knowledge on soil properties likely to influence P sorption in tephra soils is very important for sustainable management of available P. Sorption studies on six tephra soils were conducted to relate P sorption to soil characteristics in order to identify those with potential influence on P sorption. Four equilibrium-based sorption models commonly encountered in soil studies (Langmuir, Freundlich, Temkin, and Van Huay) were used to describe P sorption in the soils. P sorption was determined by measuring the residual P content of a clarified equilibrating solution of 0.02 N KCl containing varying concentrations (0, 5, 10, 15, 30, 40, 50, 60, 80, and 100 mg/L) of P as KH2PO4 after mixing with 1 g of soil in duplicates for 16 hours at 25°C. Maximum amount of P sorbed for the varying P concentrations used ranged from 2080 to 5402 mg/kg with a potential for greater P sorption maxima at higher P solution concentrations. P sorption in these soils was best described by the Langmuir and Freundlich models. Allophane and ferrihydrite are the principal species controlling the high P sorption in these soils. pH-NaF proved to be a potentially reliable test for assessing the presence of allophanic materials and thus for estimating P sorbed. This work would guide both effective and efficient P fertilizer management with economic implications for both the study area and similar environments.

关键词： Allophane Ferrihydrite Mount Kupe Mount Manengouba Sorption Isotherms

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Germination and Early Seedling Growth of Moringa oleifera Lam with Different Seeds Soaking Time and Substrates at the Yongka Western Highlands Research Garden Park (YWHRGP) Nkwen-Bamenda, North-West Cameroon

引用

American Journal of Plant Sciences 2016年第15期7卷 2173-2185页

作者： bernard palmer kfuban yerima Grace Mbakpor Ayuk Roger Kogge Enang Nicole Guehjung Yanick Alphonse Tiamgne Department of Soil Science University of Dschang Dschang Cameroon Department of Crop Production University of Dschang Dschang Cameroon Ministry of Agriculture and Rural Development West Region Cameroon

Moringa oleifera is a multipurpose tree used to remedy problems related to food insecurity and soil fertility degradation. Proper husbandry of this crop is contingent on the use of seedlings of good quality. This study aimed at assessing the germination and early seedling growth with different soaking durations and substrates composition. The seeds were obtained from the Far North region of Cameroon. A randomized complete block design with three replications was used. Two factors were tested;soaking duration with 4 treatment levels of 0 day, 4 days, 8 days and 12 days and substrates with 8 treatment levels: 100% soil, 75% soil + 25% poultry manure (PM), 50% soil + 50% PM, 25% soil + 75% PM, 100% sand, 75% sand + 25% PM, 50% sand + 50% PM and 25% sand + 75% PM. Germinated seeds and growth parameters were collected after every 5 days. The results showed that soaking duration and substrate composition influence germination and initial development of M. oleifera (p ≤ 0.05). At 25 days after soaking (DAS), soaking durations of 0 day (68.7%) and 8 days (53.1%) showed the highest germination percentages while seeds soaked for 12 days occupied the least position with 37.5%. At the same time, 75% soil + 25% PM (68.7%), 100% sand (64.5%) and 100% soil (60.5%) with the unsoaked seeds showed the highest germination percentages. The least germination percentages were represented by 50% sand + 50% PM and 25% sand + 75% PM with 35.5% and 27%, respectively. Unsoaked seeds with the substrates of 50% soil + 50% PM are the best practice for M. oleifera seedling production in the nursery.

关键词： Soaking Substrate Composition Germination Initial Growth Western Highlands

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Influence of Different Geomorphic Surfaces and Profile Modification on the Growth of <i>Maesopsis eminni</i>(Engl) at the Yongka Western Highlands Research Garden Park Nkwen-Bamenda, North West Cameroon

引用

American Journal of Plant Sciences 2017年第1期8卷 69-84页

作者： bernard palmer kfuban yerima Roger Kogge Enang Claude Assembo Makem Nicole Guehjung Grace Mbakpor Ayuk Department of Soil Science University of Dschang Dschang Cameroon Ministry of Agriculture and Rural Development West Region Cameroon Department of Crop Production University of Dschang Dschang Cameroon

The growth of Maesopsis under the influence of various geomorphic surfaces was followed within a period of 70 months. Young plants of two months old were transplanted into 70 × 70 × 70 cm holes under natural conditions (no inputs such as manure and other amendments). A randomized complete block design was set up for the experiment, alongside a control, and growth parameters followed (height and collar circumference). Three blocks with different geomorphic surfaces were put in place for the experiment (upper slope or block 1, middle slope or block 2 and foot slope or block 3). Results of the experiment indicated that geomorphic surface had a significant effect on height but not on collar circumference. Plant height increased progressively from upper slope to foot slope;less tall trees were found at the upper slope, while the tallest trees were found at the foot slope. After 70 months, maximum average height attained by plants for the experiment was 1228.3 cm, observed in block 3 (foot slope), significant at 0.05 confidence level with respect to geomorphic surface. In blocks 1 and 2 (upper slope and middle slope), maximum average heights attained were 798.5 and 937.5 cm, respectively and were shown to be statistically equal at 0.05 confidence level. Geomorphic surface had no effect on collar circumference. Maximum average collar circumferences attained after 70 months were 62.8 cm (observed at the upper slope), 61.3 cm (observed at the middle slope) and 76.3 cm (observed at the foot slope) and the various collar circumferences were shown to be statistically the same at 0.05 confidence level. For the control, maximum height attained after 70 months was 1240 cm (observed at the foot slope). At the upper slope and middle slope, maximum average heights were respectively, 800 cm and 905 cm, and were statistically equal at the 0.05 confidence level but different from the foot slope value of 1240 cm. Maximum average collar circumference was observed at the foot slope (76.3 c

关键词： Maesopsis Upper Slope Middle Slope Foot Slope Height Collar Circumference Profile Modification Induced Hydrolysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：