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Effect of rangeland rehabilitation on the herbaceous species composition and diversity in Suswa catchment,Narok county,kenya

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Ecological Processes 2017年第1期6卷 427-435页

作者： N.J.Ombega S.M.Mureithi O.k.koech A.N.karuma c.k.k.gachene Department of Land Resource Management and Agricultural Technology(LARMAT) University of NairobiP.O Box 29053Nairobi 00625Kenya Sustainable Land Management(SLM)Agro-Pastoral Project kenya NairobiKenya

Introduction:Land degradation is a serious environmental problem of our *** kenya,it is estimated that 30%of the total land mass is severely *** catchment within Narok county is a good example with gullies of over 25 m deep and 30 m *** response to the increasing land degradation in the area,the Sustainable Land Management(SLM)project rehabilitated the catchment through establishment of soil and water conservation structures such as cutoff drains,semicircular bunds,and water retention *** the various rehabilitation approaches carried out,little research has been done to ascertain their effect on successful vegetation *** coupled with the fact that many restoration approaches have failed in East Africa and kenya in particular gave drive to the *** objective of this study was to determine the effects of rangeland rehabilitation on herbaceous species composition and diversity in a severely degraded ***:To assess the diversity of aboveground herbaceous layer in the rehabilitated and degraded areas along a slope(upper,middle,and lower),line transect and quadrat count methods were *** each slope position,three 100-m-long transects were placed across the hill parallel to one another 30 m apart using a *** species hit,the closest species to the hit,and hits on bare ground were *** the same transects,1-m2 quadrats were placed 25 m apart and aboveground biomass determined by the use of the destructive *** the determination of species richness,diversity,relative abundance,percentage cover,and species composition,the Shannon-Wiener diversity index was *** collected on vegetation attributes was subjected to analysis of variance(ANOVA)using Genstat and Tukey’s HSD post hoc used in means separation where F values were ***:The results showed that percent cover(74.67%),aboveground biomass(1459 kg/ha),relative abundance,richness,composition,and diversity of perennial grass

关键词： Rehabilitation Land degradation Slope,Herbaceous layer Biodiversity

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SUSTAINABLE DEVELOPMENT OF cROP-LIVESTOck FARMS IN AFRIcA

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Frontiers of Agricultural Science and Engineering 2021年第1期8卷 175-181页

作者： Mariana c.RUFINO charles k.k.gachene Rodrigue V.c.DIOGO James HAWkINS Alice A.ONYANGO Ousmane M.SANOGO Ibrahim WANYAMA Gabriel YESUF David E.PELSTER Lancaster Environment centre Lancaster UniversityLancasterLA14YQUK Department of Land Resource Management and Agricultural Technology University of NairobiNairobiP.O.Box 29053-00625Kenya Faculty of Agricultural Sciences University of ParakouParakouP.O.Box 123Benin International Livestock Research Institute(ILRI) NairobiP.O.Box 30709-00100Kenya Institut d'Economie Rurale SikassoBP 16Mali Agriculture and Agri-Food canada 2560 Blvd HochelagaQuebec CityG1V 2J3Canada

crop-livestock farms across Africa are highly variable due to in agroecological and socioeconomic factors,the latter shaping the demand and supply of livestock ***-livestock farms in Africa in the 20-first century are very different from most mixed farms elsewhere in the *** crop-livestock farms are smaller in size,have fewer livestock,lower productivity and less dependency on imported feed than farms in most countries of Europe,the Americas and the intensive agricultural systems of *** paper discusses the role African crop-livestock farms have in the broader socio-agricultural economy,and how these are likely to change adapting to pressures brought on by the intensification of food *** intensification implies increasing land productivity(more food per hectare),often leading to more livestock heads per farm,producing fertilized feeds in croplands and importing feed supplements from the *** discussion includes(1)the links between crop yields,soil fertility and crop-livestock integration,(2)the increasing demand for livestock products and the land resources required to meet to this demand,and(3)the opportunities to integrate broader societal goals into the development of crop-livestock *** is ample room for development of crop-livestock farms in Africa,and keeping integration as part of the development will help prevent many of the mistakes and environmental problems related to the intensification of livestock production observed elsewhere in the *** development can integrate biodiversity,climate change adaptation and mitigation to the current goals of increasing productivity and food *** inclusion of broader goals could help farmers access the level of finance required to implement changes.

关键词： finance integrate goals

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

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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

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