Oumarou Malam Issa

Oumarou Malam Issa
Université de Reims Champagne-Ardenne | URCA · UFR Sciences Exactes et Naturelles

PhD

About

75
Publications
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Introduction
Oumarou Malam Issa currently works at the french institute for research and sustainable development, IRD. Oumarou does research in Soil Science. The main research topic of Oumarou is related to the relationship between evolution of soil structure and water dynamics and erosion processes. He has a high expertise in biological soil crusts and their impacts on water/wind erosion and infiltration. Their most recent publication is 'Les voies de l'éthique de la recherche au Laos et dans les pays du Mékong : santé, environnement, sociétés'.

Publications

Publications (75)
Article
Full-text available
Studies of biological soil crusts (biocrusts) have proliferated over the last few decades. The biocrust literature has broadened, with more studies assessing and describing the function of a variety of biocrust communities in a broad range of biomes and habitats and across a large spectrum of disciplines, and also by the incorporation of biocrusts...
Article
Full-text available
Striga is among the most noxious parasitic plant genera causing yield losses to staple crops in the semiarid and subhumid areas of Africa and Asia. Understanding the factors that affect the current distribution of Striga infestation is critical for developing integrated control strategies. This study attempts to elucidate the soil properties that a...
Article
Full-text available
The increasing severity of Striga gesnerioides attacks on cowpea across West Africa has been related to its prolificity, seed mobility and longevity, and adaptation to aridity, in a context of agricultural intensification. To understand this fast extension, we analyzed (1) the distributions of the crop and the witchweed with ecological niche modeli...
Article
Full-text available
The increasing severity of Striga gesnerioides attacks on cowpea across West Africa has been related to its prolificity, seed mobility and longevity, and adaptation to aridity, in a context of agricultural intensification. To understand this fast extension, we analyzed (1) the distributions of the crop and the witchweed with ecological niche modeli...
Article
Full-text available
The capture and use of water are critically important in drylands, which collectively constitute Earth's largest biome. Drylands will likely experience lower and more unreliable rainfall as climatic conditions change over the next century. Dryland soils support a rich community of microphytic organisms (biocrusts), which are critically important be...
Presentation
Striga gesnerioides (Willd.) Vatke. constitutes a biotic serious agronomic threat to tropical and subtropical areas for cowpea [Vigna unguiculata (L.) Walp)].Among the environmental parameters, soils are key factors in determining the distribution of this parasitic weed.The assessment of the relationship between S. gesnerioides and soil physicochem...
Article
Full-text available
Taking into account local knowledge of soil surface variability is a lever to optimize vegetable production and develop sustainable management strategies for Sahelian agrosystems. This study dealt with local knowledge of soil surface variability and assessment of their suitability for cowpea production in the Sahelian zone of Niger. It aimed to eva...
Article
Full-text available
Soil fertility management has always been a major concern in farms in the Sahelian zone. Some farming practices such as the periodic mobility of habitat within the fields provide a means of restoring soil fertility in western part of Niger. This work aims to study the effect of this practice on soil quality in the village of Sadoré. Surveys were co...
Article
Full-text available
La gestion et le maintien de la fertilité des sols ont été toujours une préoccupation majeure dans les exploitations agricoles en zone sahélienne. Certaines pratiques paysannes comme la mobilité périodique de l'habitat à l'intérieur des champs constituent un moyen pour restaurer les sols dégradés dans l'Ouest nigérien. Ce travail vise à étudier l'e...
Poster
Full-text available
Le niébé (Vigna unguiculata (L.) Walp.) est une légumineuse d'importance alimentaire, fourragère et commerciale au Niger. Cependant, la productivité du niébé est considérablement réduite par les attaques de bioagresseurs, dont le Striga gesnerioides (Willd.) Vatke. En effet, la compréhension de la niche écologique du S. gesneroides à travers la mod...
Poster
Le niébé (Vigna unguiculata (L.) Walp.) est une légumineuse d'importance alimentaire, fourragère et commerciale au Niger. Cependant, la productivité du niébé est considérablement réduite par les attaques de bioagresseurs , dont le Striga gesnerioides (Willd.) Vatke. En effet, la compréhension de la niche écologique du S. gesneroides à travers la mo...
Presentation
Full-text available
Le Striga gesnerioides constitue une des contraintes biotiques majeures à laquelle la culture de niébé, Vigna unguiculata (L.) Walp), fait face et qui contraint sa production. La sensibilité de variétés de niébé au striga peut être expliquée par la génétique des plantes, les conditions environnementales ainsi que les interactions qu’il y a entre el...
Poster
Full-text available
Le niébé (Vigna unguiculata (L.) Walp.) est une légumineuse d'importance alimentaire, fourragère et commerciale au Niger. Cependant, la productivité du niébé est considérablement réduite par les attaques de bioagresseurs , dont le Striga gesnerioides (Willd.) Vatke. En effet, la compréhension de la niche écologique du S. gesneroides à travers la mo...
Article
Full-text available
West Africa is a region in fast transition from climate, demography, and land use perspectives. In this context, the African Monsoon Multidisciplinary Analysis (AMMA)–Couplage de l’Atmosphère Tropicale et du Cycle eco-Hydrologique (CATCH) long-term regional observatory was developed to monitor the impacts of global change on the critical zone of We...
Article
Full-text available
West Africa is a region in fast transition from climate, demography, and land use perspectives. In this context, the African Monsoon Multidisciplinary Analysis (AMMA)-Couplage de l'Atmosphere Tropicale et du Cycle eco-Hydrologique (CATCH) long-term regional observatory was developed to monitor the impacts of global change on the critical zone of We...
Article
Several studies have demonstrated the great range of possibilities offered by remote sensing in identifying, estimating and mapping biological soil crust (BSC) patterns, i.e. a feature recognised to play major functions in drylands. However those techniques are suitable mainly where BSC patterns are abundant (> 30%) and vegetation cover low (< 10%)...
Article
Full-text available
La plaine alluviale du fleuve Niger à Niamey connaît depuis 2010, des inondations récurrentes qui provoquent des dégâts socioéconomiques et environnementaux considérables. Des études antérieures ont montré le rôle des facteurs aggravants comme les fortes précipitations et la déforestation des versants. L'objectif de cette étude est de montrer le rô...
Chapter
Biocrusts exert a strong influence on hydrological processes in drylands by modifying numerous soil properties that affect water retention and movement in soils. Yet, their role in these processes is not clearly understood due to the large number of factors that act simultaneously and can mask the biocrust effect. The influence of biocrusts on soil...
Article
Full-text available
Small portable rainfall simulators are considered a useful tool to analyze soil erosion processes in cultivated lands. European research groups in Spain (Valencia, Málaga, Lleida, Madrid and La Rioja), France (Reims) and Germany (Trier) have used different rainfall simulators (varying in drop size distribution and fall velocities, kinetic energy, p...
Article
This study was conducted in Champagne vineyards in France, and the objectives were to compare the main cultivation practices in Champagne vineyards and to specify the conditions required for the optimum effect of inter-row grass cover on runoff and erosion in experimental plots of 0.25 m² under simulated rainfall. Three types of ground cover were s...
Article
Water erosion is a natural processes particularly developed in semi-arid and arid regions, where soils can be really vulnerable. Erosion is thus the first step to desertification. In Sahelian region, concentrated overland flow often leads to the formation of gullies. Although this phenomenon is widespread in those regions, research efforts are stil...
Article
Full-text available
La crue de 2012 a Niamey : un paroxysme du paradoxe du Sahel ? E n ao^ ut 2012, le fleuve Niger a connu une crue exceptionnelle dans le bassin du Niger moyen. Plusieurs episodes pluvieux parfois exceptionnels se sont succ ed e dans ce bassin et notamment sur le bassin-versant des affluents burkinab es. Elle a provoqu e de tr es graves inondations d...
Article
Biological soil crusts occur extensively in semi-arid regions; in western Niger, they are associated with various types of physical soil crusts in fallows and in the "tiger bush ecosystem" (landscape with a typical banded pattern consisting of densely vegetated bands of small trees and shrubs alternating with bare soil bands). The objectives of thi...
Article
Full-text available
In Sahelian region, concentrated overland flow often leads to the formation of gullies. Although this phenomenon is widespread in those regions, research efforts are still needed to be able to model their spatial distribution and the role of the different parameters involved in this process. In this context, the objectives of this study are twofold...
Article
The Sahel region in West Africa is highly vulnerable facing soil degradation due to the harsh climatic conditions, with variable rainfall, and high anthropic pressure on land use. In Sahel, as in other arid environments, biological soil crusts are present over a large area. The BIOCRUST project focuses on the use of BSC as an indicator of environme...
Article
Full-text available
In Sahelian region, concentrated overland flow often leads to the formation of gullies. Although this phenomenon is widespread in those regions, research efforts are still needed to be able to model their spatial distribution and the role of the different parameters involved in this process. In this context, the objectives of this study are twofold...
Article
Full-text available
In the Sahel, crop residues are well known to reduce wind erosion. But these crop residues were studied on controlled experimental plots with amounts much higher than those traditionally encountered on cultivated fields. This work aims i) to monitor crop residues on traditional field and to quantify its influence on wind erosion ii) to characterize...
Article
Biological soil crusts occur extensively in semi-arid regions; in western Niger, they are associated with various types of physical soil crusts. The objective of this study is to elaborate and calibrate a dynamic erosion model coupling the Shallow Water equations with the Hairsine-Rose model for different sediment size classes. The study is based o...
Article
Full-text available
Land degradation and desertification are among the major environmental problems, resulting in reduced productivity and development of bare surfaces in arid and semi-arid areas of the world. One important factor that acts to increase soil stability and nutrient content, and thus to prevent water and wind erosion and enhance soil productivity of arid...
Article
Most areas where biological soil crusts (BSC) develop undergo a climate with heavy but sparse rainfall events. The hydrological response of the BSC, namely the amount of runoff, is highly variable. Rainfall simulation experiments were conducted in Sadoré, south-western Niger. The aim was to estimate the influence of the BSC coverage on the quantity...
Article
Biological soil crusts (BSC) are organo-mineral complexes resulting from the colonisation of soil surface by living microorganisms, mainly cyanobacteria. Their form, structure and composition vary depending on characteristics related to soils, biological composition and external factors (climate conditions and land uses). This study focussed on the...
Article
Biological soil crusts (BSC) are key component of arid and semiarid ecosystems due to their ability to incorporate C and N from atmosphere to soil. However, while BSC characteristics and impact on water cycle or N fixation fluxes in Sahelian zone were studied, the turnover of the fixed C and N in soils was not studied yet. The aim of this study is...
Article
Local knowledge, i.e. knowledge based on accumulation of observations is of great interest for many scientific fields as it can help for identification, evaluation and selection of relevant indicators and furthermore for progress through conservation goals. This study aimed at gathering and understanding the local knowledge and perception of biolog...
Article
Biological soil crusts (BSC) are common soil feature in the Sahel, in Western Niger. They occur in association with various types of physical soil crusts in fallow, rangeland and 'tiger bush' biomes (landscape with a typical pattern consisting of alternating dense thicket bands composed of shrubs and small trees, and bare soil bands). Despite their...
Article
Biological Soil crusts (BSC) are widespread in semi arid areas like the Sahel where they are colonizing sandy soils prone to water and wind erosions. This study aimed at understanding the effect of BSC on wind erosion. It was performed at the ICRISAT Sahelian Center of Sadore (Niger) in an old fallow. The annual rainfall depth is around 560 mm. The...
Article
Biological soil crusts occur extensively in semi-arid regions. In the western part of Niger, they are associated with various types of physical soil crusts in fallows and in the “tiger bush ecosystem” (a landscape with a typical banded pattern consisting of densely vegetated bands of small trees and shrubs alternating with bare soil bands). Despite...
Article
Full-text available
The objective of this study is to validate an approach based on the change detection in multitemporal TerraSAR images (X-band) for mapping soil moisture in the Sahelian area. In situ measurements were carried out simultaneously with TerraSAR-X acquisitions on two study sites in Niger. The results show the need for comparing the difference between t...
Article
Land degradation and desertification are among the major environmental problems, resulting in reduced productivity and development of bare surfaces in arid and semi-arid areas of the world. One important factor that acts to increase soil stability and nutrient content, and thus to prevent water and wind erosion and enhance soil productivity of arid...
Article
Microbiotic soil crusts are common features of the surface of fallow land in Western Niger. We investigated the interaction between these microbial covers and the porosity and water dynamics of soils at the surface of a Sahelian landscape. The soil pore system was examined by microscopic observations and mercury porosimetry. The soil water retentio...
Article
Many soils in South Africa have low nutrient supply, poor structural stability and are prone to soil erosion due to susceptibility to surface sealing and crusting. Two crusting soils from the Eastern Cape Province, South Africa were used to evaluate the effects of inoculation with a strain of Nostoc on soil structure, fertility and maize growth. Th...
Article
Full-text available
Cyanobacteria are widespread photosynthetic microorganisms among which some are able to fix atmospheric nitrogen. We investigated the impact of indigenous cyanobacteria strains (Nostoc) inoculation on physical characteristics of poorly aggregated soils from Guquka (Eastern Cape, South Africa). The soil aggregates (3–5 mm) were arranged into a layer...
Article
Full-text available
Field- and laboratory-scale rainfall simulation experiments were carried out in an investigation of the temporal variability of erosion processes on interrill areas, and the effects of such variation upon sediment size characteristics. Poorly aggregated sandy soils from the semi-arid environment of Senegal, West Africa, were used on both a 40 m2 fi...
Article
An experiment has been carried out in order to both measure the unsaturated hydraulic conductivity of a soil crust when it is developing and to characterize its macro- and microstructural evolution. Five stages of a structural crust developing in a loamy clay soil have been identified. Mercury intrusion experiments and micromorphological descriptio...
Article
Splash is an important process in interrill erosion because it produces movement of soil fragments. However, this process is technically difficult to measure and little is known about its size selectivity. In this study, a splash ring device was used to characterise the spatial variation of the quantity and the aggregate size distribution of splash...
Article
Full-text available
La porosité du sol est une caractéristique majeure contrôlant les propriétés hydrodynamiques du sol et le développement racinaire des plantes, mais aussi un indicateur physique de la qualité du sol influencé par les différentes techniques culturales. Cette étude s'intéresse à la détermination des effets des techniques culturales sur le système pora...
Article
Understanding the evolution of hydraulic parameters during the different stages of crust formation is necessary to predict infiltration in crusted soil. However, only a few studies have focused on the dynamics of parameters that control infiltration through a developing crust. This study reports the results of laboratory experiments carried out with...
Article
Cyanobacteria are widespread photosynthetic organisms among which some are able to fix nitrogen. In arid environment, they form tough, entangled structures that render stability to the soil surface and protect it from erosion. They have been widely used as natural fertilizer in wetland rice crop. The present study is part of an EU project (Cyanosoi...
Article
Full-text available
La croissance de souches indigènes de cyanobactéries sur des sols pauvres dans les régions semi-arides de l'Afrique Australe pourrait être une solution pour remédier aux rendements faibles et à l'érosion des sols. Le travail présenté fait partie d'un projet européen nommé "CynaSoils", qui a pour but d'améliorer la fertilité des sols dans ces région...
Article
Cyanobacterial crusts developing on the sandy and loamy soils of fallow lands in the Sahel (Niger) were investigated for their potential to fix nitrogen. Three sites were selected in this arid environment, differing in sediment type and species composition. In the sandy sites heterocystous nitrogen-fixing cyanobacteria were present, whereas the loa...
Article
Microbiotic soil crusts, mostly formed by cyanobacteria, are widespread on the surface of fallow land in western Niger. They lie adjacent to completely bare soils. We have investigated the structural stability of these soils by testing aggregate breakdown under fast-wetting, slow-wetting and mechanical breakdown. The tests were effected on aggregat...