291 research outputs found

    Botanical Knowledge and its Differentiation by Age, Gender and Ethnicity in Southwestern Niger

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    Indigenous knowledge is unevenly distributed. Individual knowledge level may be affected by many factors such as gender, age, ethnicity, profession, religious and cultural beliefs, abundance and usefulness of the species. This study documents indigenous knowledge of herbaceous and woody plant species of farmers and herders in southwestern Niger. Specifically, we examine the effects of age, gender, and ethnicity on knowledge of local vegetation. Results from the study showed that on average a higher proportion of woody species was identified by the respondents compared to herbaceous species. Both gender and ethnicity had a significant effect on the identification of herbaceous species but no effect on identification of woody species. Respondents in lower age group (10 to 30 years) identified lower number of species compared to other age classes. There seems to be a curvilinear relationship between age of respondents and number of plant species identified. Results from this study reaffirm the uneven distribution of indigenous knowledge within a given area due to social factors. The main challenge is how to incorporate these social differences in knowledge of native plant species into sustainable management and conservation of community natural resources

    Less rain, more water in ponds: a remote sensing study of the dynamics of surface waters from 1950 to present in pastoral Sahel (Gourma region, Mali)

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    Changes in the flooded area of ponds in the Gourma region from 1950 to present are studied by remote sensing, in the general context of the current multi-decennial Sahel drought. The seasonal and interannual variations of the areas covered by surface water are assessed using multi-date and multi-sensor satellite images (SPOT, FORMOSAT, LANDSAT-MSS, –TM, and -ETM, CORONA, and MODIS) and aerial photographs (IGN). Water body classification is adapted to each type of spectral resolution, with or without a middle-infrared band, and each spatial resolution, using linear unmixing for mixed pixels of MODIS data. The high-frequency MODIS data document the seasonal cycle of flooded areas, with an abrupt rise early in wet season and a progressive decrease in the dry season. They also provide a base to study the inter-annual variability of the flooded areas, with sharp contrasts between dry years such as 2004 (low and early maximal area) and wetter years such as 2001 and 2002 (respectively high and late maximal area).The highest flooded area reached annually greatly depends on the volume, intensity and timing of rain events. However, the overall reduction by 20% of annual rains during the last 40 years is concomitant with an apparently paradoxical large increase in the area of surface water, starting from the 1970's and accelerating in the mid 1980's. Spectacular for the two study cases of Agoufou and Ebang Mallam, for which time series covering the 1954 to present period exist, this increase is also diagnosed at the regional scale from LANDSAT data spanning 1972–2007. It reaches 108% between September 1975 and 2002 for 91 ponds identified in central Gourma. Ponds with turbid waters and no aquatic vegetation are mostly responsible for this increase, more pronounced in the centre and north of the study zone. Possible causes of the differential changes in flooded areas are discussed in relation with the specifics in topography, soil texture and vegetation cover over the watersheds that feed each of the ponds. Changes in rain pattern and in ponds sedimentation are ruled out, and the impact of changes in land use, limited in the area, is found secondary, as opposed to what has often been advocated for in southern Sahel. Instead, major responsibility is attributed to increased runoff triggered by the lasting impact of the 1970–1980's droughts on the vegetation and on the runoff system over the shallow soils prevailing over a third of the landscape

    Time Budget on Major Activities of Livestock Grazing Heterogeneous Natural Range and Crop Fields in Semi-Arid Nigeria

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    Semi-arid rangelands of West Africa provide herbs, trees and shrubs, which together with crop residues form the main sources of feed for the livestock population. Feed supply in this region is characterised by a progressive decline in quantity and quality with advancing dry season. It was reported that walking ability as well as watering frequencies affect the productivity of grazing livestock (Dicko and Sangare, 1984). This study tests the hypothesis that advancing season increases both time spent walking as well as feeding, with a switch from grazing to browsing

    Implications of Land Use Changes on the Yields in Dry Matter, Energy and Protein of Range and Crop Fields in Zamfara Reserve, Northwestern Nigeria

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    The Zamfara reserve is a 235,500 ha grazing land within the Sudan savannah zone (12Âș 10\u27 - 13Âș 05 N; 6Âș 30\u27 - 7Âș15\u27 E) of north western Nigeria. Rainfall varies from 500mm in the north to 800mm in the south of the reserve, and is restricted within the months of May - September. The reserve is an important grazing site for the herds of sedentary, transhumant and agro pastoralists. Population growth within the farming communities in the reserve has led to the conversion of more grazing land to croplands. This work was carried out to evaluate the quantity and quality of herbage on the natural range and the croplands, in order to have an insight on the effect of increased cropping activity on biomass availability in the reserve

    Population genetic responses of wild forage species to grazing along a rainfall gradient in the Sahel: A study combining phenotypic and molecular analyses

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    Abstract Genetic diversity was studied in wild forage species subjected to grazing along a rainfall gradient in West Niger, within the Sahel with aim of identifying adapted genotypes, which could be used to reclaim degraded land. Two legumes (Alysicarpus ovalifolius and Zornia glochidiata) and two grasses (Brachiaria xantholeuca and Cenchrus biflorus) were selected to relate phenotypic adaptation to genetic diversity in response to grazing and rainfall. Populations of each species were sampled from both heavily grazed and ungrazed sites along a rainfall gradient, approximating 200 mm yr -1 to 800 mm yr -1 rainfall isohyets. The adaptative phenotypic expressions to aridity and grazing of the populations from each of the species were characterised by morphological measures performed on the plants sampled in the field. These analyses were then compared with the results from genetic analyses using the PCR-based techniques of amplified fragment length polymorphism (AFLP) and random amplified * Equal contribution to this work by both authors. R. Jamnadass ( ) · A. Muchug

    Destructive and non-destructive measurements of residual crop residue and phosphorus effects on growth and composition of herbaceous fallow species in the Sahel

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    Little is known about the residual effects of crop residue (CR) and phosphorus (P) application on the fallow vegetation following repeated cultivation of pearl millet [Pennisetum glaucum (L.) R. Br.] in the Sahel. The objective of this study, therefore, was (i) to measure residual effects of CR, mulched at annual rates of 0, 500, 1000 and 2000 kg CR h

    Imaginarios en disputa o sobre la territorialización de un conflicto urbano. El caso de “La Canchita de los Bomberos” (Mar del Plata, Argentina)

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    Apenas transcurridos tres meses de la creaciĂłn del Programa CrĂ©dito Argentino del Bicentenario para la Vivienda Única Familiar, el Municipio de General PueyrredĂłn anuncia las tierras disponibles para comprometer en su implementaciĂłn; entre ellas, el predio conocido como Canchita de los Bomberos de la ciudad de Mar del Plata. Frente a ello, se conforma un grupo de vecinos autoconvocados en defensa de su utilizaciĂłn como espacio pĂșblico-verde, llevando a cabo diversas estrategias cuyo objetivo es evitar la construcciĂłn de viviendas en esa zona. Paralelamente, otras personas manifiestan su parecer en relaciĂłn a la ejecuciĂłn del programa y desarrollan prĂĄcticas que cuestionan la legitimidad de las demandas sostenidas por aquellos vecinos. El propĂłsito del artĂ­culo es analizar las formas de apropiaciĂłn simbĂłlica que se refuerzan y/o modifican en funciĂłn de la disputa; lo que MelĂ© (2003) llama el proceso de territorializaciĂłn del conflicto. Se argumenta que, aunque se produce un choque de imaginarios (Hiernaux; 2008a), emerge un imaginario dominante que logra imponerse y legitimar el uso y disfrute del espacio a su favor

    Milking the data: Measuring milk off-take in extensive livestock systems. Experimental evidence from Niger

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    Milk is an important source of cash and nutrients for many households in developing countries. Yet, our understanding of the role of dairy production in livelihoods and nutritional outcomes is hindered by the lack of decent quality household survey data. Data on milk off-take for human consumption are difficult to collect in household surveys for a number of reasons which make accurate recall challenging for the respondent (continuous production and seasonality among others), introducing possibly severe biases in the computation of full household incomes and farm sales, as well as in the estimation of the contribution of livestock (specifically dairy) production to agricultural value added and the livelihoods of rural households.This paper presents results from a validation exercise implemented in Niger, where alternative survey instruments based on recall methods were administered to randomly selected households, and compared to a 12-month system of physical monitoring and recording of milk production. The results of the exercise show that reasonably accurate estimates via recall methods are possible, and provide a clear ranking of questionnaire design options that can inform future survey operations

    Fertility management and landscape position: farmers' use of nutrient sources in western Niger and possible improvements

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    Poor millet growth and yields in Niger are commonly attributed to rainfall deficits and low soil nutrient content. Land management by local farmers is done as a function of soil types, crops, and available resources. Farmer management practices in millet fields located on four different landscape positions were studied in a village in western Niger located near the 600 mm isohyet. Average distance from homestead to field was 980 m, with fields in the valley bottom much closer (average 225 m) and fields on the plateau much further (average 2300 m). Farmers considered the valley and plateau fields slightly more fertile than the other fields, but rainfall infiltration on plateau fields is often relatively poor. Nitrogen and phosphorus contents in the soil were highest on the less intensively cropped plateaus. More than 50% of the fields did not receive any applied nutrients other than during livestock grazing of leftover stover. Manure application was done through corralling in only four of the fields studied (20%), out of which three were farmed by Fulani using their own herds for manuring. There was no significant effect of landscape unit on yield, though yields in the valley and on the upper slope were slightly higher than average. Millet grain yields, soil carbon and soil phosphorus decreased significantly with distance from the living quarters. This may be because manuring usually takes place close to home (average distance in 1997 <200 m). Manure application increased millet grain production from 126 kg ha−1 to 316 kg ha−1 in 1997. Manuring yielded more than 1000 kg ha−1 in 1996, when rainfall was much more favourable. Fallowed fields yielded an average 143 kg ha−1 of millet grain in 1997, with fallow taking place an average of 1640 m from the homestead. Another soil fertility management practice included use of millet threshing residues in fields adjacent to the village. There was no chemical fertilizer application. Any improvement to the system will require the solution of existing constraints limiting the integration of livestock and crops and/or limiting the input of external sources of nutrients in Niger. These limitations can include lack of land to allow fallowing practices and/or grazing; local non-availability of mineral fertiliser; lack of capital to buy fertiliser, due in part to low millet prices; lack of means of transport for inputs; but also lack of means for pest control and lack of labour for sowing, weeding and thinning. Initial improvements may be made by making more efficient use of the available manure, through much lighter and slightly more frequent manuring of much larger area
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