检索结果-南通市图书馆

Functional attributes： compacting vs decompacting earth- worms and influence on soil structure

current Zoology 2012年第4期58卷 556-565页

作者： Arnauth MartinezGUEI Yannick BAIDAI Jerome Ebagnerin ToNDoH Jeroen HUISING Universit6 Abobo-Adjam6 Sciences de la Nature/Centre de Recherche en Ecologie 08 BP 109 Abidjan 08 C6te d'Ivoire ciat-tsbf Institut d'Economie Rurale CRRA de Sotuba Laboratoire Sol-Eau-Plante c/o Icraf Sahel BPE 5118 B amako Mali ciat-tsbf nairobi c/o icraf United Nations Avenue P.O. Box 30677-00100 Nairobi Kenya

A short term field mesocosm experiment was performed in semi-deciduous forest areas of Ivory coast to assess the impact of a decompacting （Hyperiodrilus africanus, Eudrilidae） and two compacting （Millsonia omodeoi and Dichogaster terrae nigrae, Acanthodrilidae） earthworm species on soil properties. These species have been selected for their predominance in the re- gion and their contrasting impact on soil structure. The experimental design consisted of a treatment without worms （control）, and treatments with one, two or three species of earthworms. Both compacting and decompacting earthworms increased water infil- tration rate in all treatments, with marked impact in H. africanus and M. omodeoi＋D, terraenigrae treatments. Interactions be- tween compacting and decompacting species resulted in more large aggregates in comparison to when the compacting species D. terraenigrae was alone. This may be accounted for by their compacting attribute as compacting earthworms are responsible for producing the highest number of large aggregates. The low values of mean weight diameter in treatments combining decompact-ing and compacting earthworms compared with compacting ＂M. omodeoi＂ one also confirmed the trend of decline in soil com-paction in the presence of the decompacting species. These results showed positive impact of species richness on soil structure regulation, which is crucial in ecosystem productivity and support consequently the insurance hypothesis. In fact, this study showed that the preservation of earthworm species belonging to these two contrasting functional groups is essential for the main-tenance of stable soil structure regulation in agro-tropical ecosystems.

关键词： Earthworms Physical properties compacting and decompacting species Mesocosms

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

Diagnosis of Soil Nutrient constraints in Small-Scale Groundnut （Arachis hyopaea L,） Production Systems of Western Kenya Using Infrared Spectroscopy

引用

Journal of Agricultural Science and Technology(A) 2011年第1X期1卷 111-127页

作者： S. I. Muhati K. D. Shepherd c. K. Gachene M. W. Mburu R. Jones G. o. Kironchi A. Sila University ofnairobi (UoN) P.O. Box 30197 Nairobi Kenya World Agroforestry centre (icraf) P.O. Box 30677-00100 Nairobi Kenya International crop Research Institute for Semiarid Tropics (1cRISA T) P.O. Box 30677-00100 Nairobi Kenya Tropical Soil Biology and Fertility Research Area of International center for Tropical Agriculture (tsbf-ciat) P.O. Box 30677-00100 Nairobi Kenya

Wise decision-making on resource allocation and intervention targeting for soil management cannot rely solely on trial and error methods and field observations used by small-scale farmers： cost-effective soil fertility survey methods are needed. This study aimed to test the applicability of infrared spectroscopy （IR） as a diagnostic screening tool for making soil fertility recommendations in small-scale production systems. Soil fertility survey of 150 small-scale groundnut farms in western Kenya was conducted using a spatially stratified random sampling strategy. Soil properties examined were pH in water （pHw）, total carbon （c）, total nitrogen （N）, extractable phosphorus （P）, exchangeable potassium （K）, calcium （ca）, magnesium （Mg） and texture. These properties were calibrated to mid-infrared （MIR） diffuse reflectance using partial least square regression （PLSR）. cross-validated coefficient of determination （r2） values obtained from calibration models were 〉 0.80 for all properties, except P and K with 0.66 and 0.50 respectively. Soil nutritional deficiencies were evaluated using critical nutrient limits based on IR predictions and composite soil fertility indices （SFIs） developed from the soil properties using principal component analysis. The SFIs were calibrated to MIR soil spectral reflectance with cross-validated r： values 〉 0.80. The survey showed that 56% of the groundnut farms had severe soil nutrient constraints for production, especially exchangeable ca, available P and organic matter. IR can provide a robust tool for farm soil fertility assessment and recommendation systems when backed up by conventional reference analyses. However, further work is required to test direct calibration of crop responses to spectral indicators and to improve prediction of extractable P and K tests.

关键词： Infrared spectroscopy nutrient constraints small-scale farmers soil fertility indices groundnut

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

Developments,bottlenecks,and opportunities in seed markets for improved forages in East Africa:The case of Kenya

引用

Grassland Research 2024年第1期3卷 79-96页

作者： Jesús F.Florez Peggy Karimi John J.J.Paredes Natalia T.Ángel Stefan Burkart International center for Tropical Agriculture(ciat) Tropical Forages ProgramCaliColombia International center for Tropical Agriculture(ciat) Tropical Forages ProgramNairobiKenya

Background:cattle farming plays a pivotal role in Africa's agricultural and livestock sector,poised for growth due to population expansion and rising per capita consumption of animal-sourced *** are a primary source of feed for dairy cattle,signiﬁcantly impacting production *** local forage varieties are preferred by dairy farmers,there has been an increase in the adoption of improved forages in recent ***,the overall adoption rate is still low,for example,due to underdeveloped forage seed ***:This study describes the dynamics,challenges,and potential of these markets in Kenya and selected East African countries,focusing on(i)market evolution over the past decade,(ii)forthcoming market prospects,and(iii)bottlenecks and opportunities for *** were gathered in 2022 through qualitative interviews with stakeholders representing six segments of the forage seed sector across six ***:We found a sustained growth of the improved forage seed market in recent *** main challenges for further growth are high seed prices,regulatory difﬁculties,and limited producer ***:Theﬁndings unveil positive dynamics in the region's forage seed market,fueled by the engagement and determination of stakeholders who recognize the manifold beneﬁts that it holds for both the dairy industry and economic *** realization of this market's potential requires addressing prevailing challenges,including elevated seed costs,intricate variety registration processes,and a pervasive lack of awareness among farmers.K E Y W o R D S animal productivity,dairy,improved forages,market development,sustainability,tropical forages adoption *** need to involve governmental entities and seed companies is recognized since both actors have so far mostly worked ***-theless,the strong partnership between the Alliance of Bioversity and ciat and Grupo Papalotla is highlighted as an example of coordinated work

关键词： animal productivity dairy improved forages market development sustainability tropical forages

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

Bioinventory and documentation of traditional ecological knowledge of wild edible fruits of Kodagu-Western Ghats, India

引用

Journal of Forestry Research 2014年第3期25卷 717-721页

作者： Namera c.Karun P.Vaast c.G.Kushalappa Department of Bioscience Mangalore University cIRAD UMR Eco&Sols Montpellier France icraf NairobiKenya college of Forestry (University of Agriculture Sciences) Ponnmpet Coorg 571216 India

Forty-five species of wild edible fruits were identified and traditional local knowledge of their usage was recorded in 40 villages of Kodagu district in central Western Ghats, India one of the eight top hotspots of biodiversity in the world. We combined biodiversity inven-tory of trees with village interviews to record traditional ecological knowledge. Wild edible fruits were an opportunistic source of food for rural people. Wild edible fruits were rich in minerals, vitamins, carbohy-drates, proteins, fats and fiber. In recent years there has been a decline in numbers of wild fruit trees due to changes in land use from uncultivated private wooded area to cardamom and coffee cultivation. The availability of wild edible fruits that were once very common on private cultivated areas has declined and their distributions are now restricted more to jungles and wildlife sanctuaries. We propose methods for conservation and describe the need for sustainable utilization to provide supplemen-tary sources of nutritional and pharmaceutically useful edible wild fruits.

关键词： wild edible fruits nutraceutical biodiversity Kodagu,western Ghats.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Review of Innovative Agricultural Market creation in Africa and the Study of Three-tier Model for Soybean Development and Promotion in Kenya

引用

Journal of Life Sciences 2010年第3期4卷 43-51页

作者： Jonas Nwankwo chianu Bernard Vanlauwe Akinwumi Adesina Justina Nwanganga chianu NteranyaSanginga Tropical Soil Biology and Fertility Institute of the International center for Tropical Agriculture （tsbf-cIA T） c / o Worm Agroforestry Center （ICRAF） UN Avenue Nairobi 00100 Kenya Department of Agriculture and Agro-industry （oSAN） Agricultural Fertilizer Financing Mechanism （AFFM） Belvedere Tunis 1002 Tunisia Alliance for a Green Revolution in Africa Westlands Nairobi 00800 Kenya

Agricultural market creation was critical for rural growth in Africa. How to achieve this based on crops other than major staples （e.g. maize） and traditional export crops （e.g., tea, coffee, cotton） remained a problem since most African countries did not give them policy attention. This study used a three-tier-model, developed based on successful strategies in Nigeria and Zimbabwe, to develop multi-level soybean market creation in Kenya. Data were from secondary sources, formal and informal interviews, farm-level data, and participant observations. Analysis was carried out using Microsoft Excel and SPSS. Result showed increasing in farmers＇ confidence to produce, process, consume, and sell more soybeans than before. Trained farmers＇ groups were developing new soybean products for cash, poverty reduction and improvements in livelihoods. Net returns had been increased from 4 to 14 times from processed products. Selected farmers＇ groups had begun to supply large-scale processors with soybean grains, substituting imports. The overall project＇s impact on number of participating farmer groups and the actual land area devoted to soybean cultivation ranged from a factor of 2.3 to a factor of 77.4 between the long rainy seasons of 2005 / 2006 and the short rainy seasons of 2009. Farmers had given testimonies on live improvements.

关键词： Agricultural market creation three-tier-model soybean Africa Kenya.

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

Response of soil mite abundance and diversity to a monospecific timber Tectona grandis plantation in Ivory coast

引用

current Zoology 2013年第5期59卷 633-643页

作者： Julien Kouadio N'DRI Henri Marc ANDRE Jan LAGERLoEF Jerome Ebagnerin ToNDoH Thierry HANcE UFR des Sciences de la Nature/centre de Recherche en Ecologie Universit6 d'Ab0bo-Adjam6 02 BP 801 Abidjan 02 C6te d'Ivoire Mus6e royal de l'Afrique centrale Leuvensesteenweg 13 B-3080 Tervuren Belgium Swedish University of Agricultural Sciences (SLU) Dept. of Ecology EO.Box 7044 SE-750 07 Uppsala Sweden ciat-tsbf Institut d'Economie Rurale CRRA de Sotuba Laboratoire Sol-Eau-Plante c/o Icraf Sahel BPE 5118 Bamako Mali Universite catholique de Louvain Biodiversity Research Center Earth and Life Institute Place Croix du Sud 4 B-1348 Lou-vain-la-Neuve Belgium

This study aims to assess the impact of monospecific Tectona grandis forest plantation on the soil mite abundance and diversity. To achieve these objectives, two sites situated in Ivory coast were investigated. The first, a primary forest was characterized by a very weak human activities whereas the second, a teak plantation was characterized by a high disturbance performed during the planting. After extracting, sorted and description, 116 mite species were described in the two sites. Mite densities were lower in teak plantation and also higher in the litter and decreased to the depth in both sites. Species richness re- corded in teak plantation （52 species） was significantly lower compared to primary forest （98 species）. The same trend was ob- served for oribatida but not for Gamasida. The lower oribatida （5 vs. 17） and higher oribatida （24 vs. 41） were recorded respec- tively in teak plantation and primary forest. Mite Shannon index and evenness were significantly different between sites. High Jaccard index values and the appearance of exclusive species in both habitats showed that the sites are very distinct. Total number of species recorded corresponded to 58%-63% of the total number of species estimated by AcE and chao 1＆2 estimators, indi- cating that the sampling effort was not sufficient. Mite abundance and diversity varied depending on the characteristics of habi- tats. chemical element （corn, ctot, Ntot, and SoM） values were lower in teak plantation （disturbed habitat） and significantly dif- ferent to primary forest in the topsoil. Apart from litter height, soil depth, pH and c/N ratio, others variables were strongly corre- lated to mite abundance and diversity [current Zoology 59 （5）： 633-643, 2013].

关键词： Soil mite Teak plantation Diversity and community structure Disturbance.

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

Soil Properties Degradation Assessment Using Infrared Scanning Technique of Soils （case Study： Eastern of congo）

引用

Journal of Agricultural Science and Technology(A) 2013年第9期3卷 677-688页

作者： Bashagaluke Janvier Mulumuna Janvier Pieter Pypers Walangululu Jean Shepherd Keith MochogeBenson Mugwe Jayne Vanlauwe Bernard Boeckx Pascal Universite catholique De Bukavu (UcB) DR Congo Kenyatta University Nairobi Kenya Laboratory of Applied Physical chemistry--lSoFYS Faculty of Bioscience Engineering Ghent University Coupure 6539000Gent Belgium Tropical Soil Biology and Fertility of the International Institute of Tropical Agriculture (tsbf-cIA T) Nairobi Kenya World Agro-forestry center (icraf) Nairobi Kenya

Recently, near infrared reflectance （NIR） and mid-infrared （MIR） spectroscopy techniques are increasingly introduced as convenient and simple non-destructive techniques for quantifying several soil properties. This study uses MIR method to predict pH, soil organic c, total N, AI, ca, Mg and K, cEc and soil texture for soil samples collected in Sud-Kivu, congo. A total of 536 composite soil samples were taken from two locations （Burhale and Luhihi） at two depths （0-20 cm and 20-40 cm） using a spatially-stratified random sampling design within an area of 200 km2. Differences in characteristics were evaluated between the two locations, land use （cultivated vs. non-cultivated land） with soil depths. A random subset of the samples （10%） were analyzed using standard wet chemistry methods, and calibration models developed by MIR data to estimate soil properties for the full soil sample set. Partial least squares regression （PLS） method gave acceptable coefficients of determination between 0.71 and 0.93 for all parameters. Soil organic matter levels were higher in cultivated plots in Luhihi （3.9% c） than in Burhale （3.0% c）, suggesting lower levels of soil fertility in the later area. This indicates high levels of acidity, which are likely to limit crop production in the area. Phosphorus deficiency is acute in Burhale （2.4 mg P/kg） but less in Luhihi （5.4 mg P/kg）. In both locations, low levels of ca and Mg indicate that soils may be susceptible to deficiencies in both *** findings provide new opportunities for monitoring soil quality in the region which can benefit multiple actors and scientists involved in the agricultural and environmental sectors.

关键词： Parameter depth infrared correlation prediction landuse.

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

Effects of Zero Tillage and Residue Retention on Soil Quality in the Mediterranean Region of Northern Syria

引用

open Journal of Soil Science 2014年第3期4卷 109-125页

作者： Rolf Sommer colin Piggin David Feindel Muhammad Ansar Lona van Delden Kayoko Shimonaka Jihad Abdalla osama Douba George Estefan Atef Haddad Rousheen Haj-Abdo Ali Hajdibo Pierre Hayek Yaseen Khalil Ahmed Khoder John Ryan International center for Agricultural Research in the Dry Areas (IcARDA) Aleppo Syria nternational center for Agricultural Research in the Dry Areas (IcARDA) Aleppo Syria nternational center for Tropical Agriculture CIAT Nairobi Kenya

Zero-tillage (ZT) and crop residue retention on the soil surface—two components of conservation Agriculture (cA)—have been identified as promising management practices for sustainable agri- cultural intensification for some time. However, cA technology uptake by farmers in the dry areas of West Asia and North Africa (WANA) has yet to happen large-scale, even though the positive im- pact on yield has been demonstrated repeatedly. To explain the observed consistent increases in crop yield under ZT, a range of soil quality indicators were regularly monitored during 2008 to 2012 in the long-term ZT/cA trials at the headquarters of the International center for Agricultural Research in the Dry Areas (IcARDA) in northern Syria. Results showed that cA had a positive im- pact on soil fertility. This was measurable by higher soil organic matter (SoM) and microbial bio- mass contents, increased levels of extractable phosphate, sometimes (but not always) higher amounts of larger water-stable soil aggregates, increased soil infiltration capacity and soil water retention. The buildup of SoM and associated carbon (c) sequestration was in the range of 0.29 Mg c/ha/yr, i.e. rather modest. High amounts of surface residues delayed the desiccation of the topsoil during the fallow period, but could not diminish the overall longer-term drying of the topsoil. The observed positive changes in soil quality were little, but nevertheless, in combination with the economic savings that ZT offers, this type of agricultural intensification provides an attractive op- tion for farmers in WANA, from the standpoints of economy and ecological efficiency.

关键词： conservation Agriculture Soil Fertility Indicators Soil Water Evaporation Water Infiltration Water Stable Aggregates Soil carbon Sequestration

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

Testing Agro-Ecological Adaptation of Improved Herbaceous Forage Legumes in South-Kivu, D.R. congo

引用

American Journal of Plant Sciences 2014年第9期5卷 1384-1393页

作者： M. M. D. Katunga J. B. B. Muhigwa K. J. c. Kashala L. Ipungu N. Nyongombe B. L. Maass M. Peters centre International d’Agriculture Tropicale (ciat) Bukavu D.R. Congo ciat A.A. 6713 Cali Colombia ciat Nairobi Kenya officielle de Bukavu Faculté des sciences Bukavu D.R. Congo Université de Lubumbashi Faculté de Médecine Vétérinaire Lubumbashi D.R. Congo Université Pédagogique Nationale de Kinshasa Kinshasa D.R. Congo

In tropical african countries where livestock is either reared in herds on natural grasslands or individuallly tethered to herds on natural or spontaneous vegetation, the productivity is low, especially during the dry season. Using improved forages could play an important role in both enhancing livestock production and improving soil fertility and preventing from soil erosion. Eleven herbaceous forage legumes previously tested in tropical South America and South Asia by ciat were tested in South-Kivu, D. R. congo. Across sites, Stylosanthes guianensis, Desmodium uncinatum, centrosema molle and canavalia brasiliensis had a highest yield, nowhere Vigna unguiculata adapted. Differencial plant adaptation occured, e.g. clitoria ternatea being well adaptated only in the midlands with good soils, where the mean of dry mater leaf yield was higher. Farmer evaluation emphazied overall biomass production with preference in the highlands, farmers chose Desmodium uncinatum, canavalia brasiliensis and Lablab purpureus 21603 and in the midlands Stylosanthes guianensis 11995 and Lablab purpureus 22759. Farmer evaluation confirmed the best yield fit herbaceous forage legumes.

关键词： Herbaceous Forage Legumes Adaptation Tropical Africa

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

In <i>Vivo</i>Hypoglycemic Activity of Aqueous Extracts of <i>chasmanthera dependens</i>in Alloxan Induced Diabetic Mice

引用

open Journal of Applied Sciences 2021年第7期11卷 832-845页

作者： Dinah J. Sawe Eliud N. M. Njagi Alice N. Muchugi Moses Ndiema Department of Biochemistry & clinical chemistry College of Health Sciences Moi University Eldoret Kenya Department of Biochemistry Biotechnology and Microbiology School of Pure and Applied Sciences Kenyatta University Nairobi Kenya Genetic Resource Unit International Centre for Research in Agroforestry (ICRAF) Nairobi Kenya Department of Human Anatomy College of Health Sciences Moi University Eldoret Kenya

The plant chasmanthera dependens (Hochst) have been used to manage many diseases including diabetes mellitus without scientific evaluation of its efficacy and safety. The main objective of the project was to determine the antidiabetic activity of chasmanthera dependens plant in a rat model. Experimental design was used where the stem of the plant was collected, dried, crashed into fine powder, extracted with distilled water at 60°C and lyophilized using a Freeze Dryer, packaged in air tight container and stored at -20°C ready for use. The extract was orally and intraperitoneally screened in alloxan induced diabetic mice for its hypoglycemic activity at doses of 25, 48.4, 93.5, 180.9 and 350 mg per kg body weight. Diabetes in mice was induced using 186.9 mg/kg of alloxan monohydrate. Negative controls included normal and diabetic rats orally and intraperitoneally administered with physiological saline while positive controls included diabetic rats administered with glibenclamide as oral and insulin as intraperitoneal reference drug. The results revealed hypoglycemic activity in Chasmanthera dependens at the five different doses when given either orally or intraperitoneally. In conclusion, the medicinal plant at the various doses demonstrated significant (ρ ≤ 0.05) hypoglycemic activity. The author’s recommendation is continued use of the plant extracts at low therapeutic doses. Consideration should be made to carry out the same studies using higher animals including man.

关键词： Diabetes Hypoglycemia Plant Extract chasmanthera dependens Albino Mice

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

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

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：