Myriam Adam

Cirad - La recherche agronomique pour le développement | CIRAD · Unité Mixte de Recherche Amélioration Génétique et Adaptation des Plantes Méditerranéennes et Tropicales (AGAP)

Identification of best performing fertilizer practices among a set of contrasting practices with field trials is challenging as crop losses are costly for farmers. To identify best management practices, an ''intuitive strategy'' would be to set multi-year field trials with equal proportion of each practice to test. Our objective was to provide an i...

Sorghum is an important staple crop in Sub-Saharan Africa. In the Sudano-Sahelian zone of West Africa, sorghum is mainly intercropped with cowpea, but these intercropping systems are facing low-productivity problems. The overall aim of this research was to identify sorghum varieties with different agro-morphological and physiological traits that co...

Production of cereals (maize, sorghum, millet) in southern Mali is challenged by several hazards that affect yield and yield variability. The research aims to inform decision making towards effective risk management by quantifying cereal yield losses at field level due to production hazards under different management strategies. Five hazards releva...

CONTEXT The semi-arid zone of Burkina Faso is characterized by strong climate variability and declining soil fertility associated with low biomass production. OBJECTIVE The main objective of this study was to identify key levers to improve biomass management in semi-arid Burkina Faso for diverse farm types. METHODS Farm diversity was captured wit...

CONTEXT Typologies are widely used to tailor management practices to structural farm households, and to identify recommendation domains. However, it has often been shown that the recommendations are not followed by farmers, especially in the agricultural context of sub-Saharan Africa. OBJECTIVE We aimed to identify links between a typology based o...

Agriculture in West Africa is constrained by several yield-limiting factors, such as poor soil fertility, erratic rainfall distributions and low input systems. Projected changes in climate, thus, pose a threat since crop production is mainly rain-fed. The impact of climate change and its variation on the productivity of cereals in smallholder setti...

Main conclusion Plant traits of interest for sorghum breeders to develop dual-purpose varieties are stem diameter, flag leaf size, crop cycle, and number of grains per panicle. Abstract To develop dual-purpose varieties, breeders need to improve traits linked both to grain and biomass production. To identify these traits, we studied the phenotypic...

L'association sorgho/niébé au poquet, une pratique traditionnelle en zone soudano-sahélienne à faible rendement: Etat des lieux et pistes d'amélioration [ Sorghum and cowpea intercropping, a traditional practice in sudano-sahelian zone with low crop yields: What farmers are doing and potential improvements ] ABSTRACT: Cereal-legume intercropping is...

A deeper understanding of how smallholder farmers perceive and manage risks is crucial to identify options that increase farmers' adaptive capacity. We investigated a broad range of risks that play a role in farmers' decision-making processes. In the cotton zone of Mali opportunities and constraints vary with the resource endowment of farms. Furthe...

The productivity of smallholder farming systems is held back by poor soil fertility, low input levels and erratic rainfall distribution in the sorghum-based cropping systems of the Sudano-Sahelian zone of West Africa. We assessed the sensitivity of current agricultural practices to climate change and to improved management practices: (i) increased...

Smallholder farmers in sub‐Saharan Africa (SSA) currently grow rainfed maize with limited inputs including fertilizer. Climate change may exacerbate current production constraints. Crop models can help quantify the potential impact of climate change on maize yields, but a comprehensive multi‐model assessment of simulation accuracy and uncertainty i...

Crop models are powerful tools to explore agricultural impacts and adaptation to climate change. They are extensively used to predict the effect of climate change on agriculture. In this chapter, the authors review how crop models take into consideration climate variables and how they are used for climate change impact assessment studies, leading t...

This book chapter intends to equip the readers with the basic understanding of what crop models are, answer the common questions which the crop-modelling community usually receives from the other research disciplines, and briefly describe the frequent model misuses which many times hamper broader usage of models in agriculture. We will briefly disc...

Sorghum (Sorghum bicolor (L.) Moench) is one of the most resilient crops grown in the tropical, subtropical, or temperate regions of Africa, Asia, Oceania, and Americas. Globally, the top five worldwide sorghum producers are USA, Nigeria, Sudan, Ethiopia, and India. Sorghum production area is declining and shifting to lower productivity regions or...

Introducing sorghum (Sorghum bicolor L. Moench) genotypes into new environments is necessary for expanding the production of food and fuel, but these efforts are complicated by significant genotype × environment interactions that can reduce their effectiveness. This study set out to thoroughly analyze genotype × environment interactions and assess...

Soil nutrient deficiency and rainfall variability impair the production of sorghum (Sorghum bicolor (L). Moench) in Sudano-Sahelian zone. The aim is to study the environmental factors that can determine the effect of fertilizer application on sorghum grain yield and to formulate tailored fertilization strategies according to sorghum varieties (hybr...

Climate change is estimated to exacerbate existing challenges faced by smallholder farmers in Sub-Sahara Africa. However, limited studies quantify the extent of variation in climate change impact under these systems at the local scale. The Decision Support System for Agro-technological Transfer (DSSAT) was used to quantify variation in climate chan...

Objectif : L’objectif est d’étudier les réponses de variétés de sorgho à des apports contrastés de NPK et urée qui pourraient être dictés par les informations météorologiques. Méthodologie et résultats : Des essais en split plot avec quatre répétitions ont été conduits à Nioro du Rip et Sinthiou Malème (Sénégal) sur sols sableux en conditions pluvi...

Rainfall uncertainty and nutrient deficiency affect sorghum production in Sahel. This study aimed at (i) determining the responses (varieties*water*nitrogen) of various West-African sorghum (Sorghum bicolor L. Moench) varieties to the application of fertilizer (NPK and urea) at selected growing stages according to water regime (irrigated or not, di...

In West Africa's highly weathered soils, plant-available soil-P levels determine sorghum performance and yield to a far greater extent than projected variability in climate. Despite local landrace varieties having excellent adaptation to the environment and a relatively stable yield, sorghum grain yield remains quite low, averaging less than 1 t ha...

Abstract To reduce the risks of climate change, governments agreed in the Paris Agreement to limit global temperature rise to less than 2.0°C above pre-industrial levels, with the ambition to keep warming to 1.5°C. Charting appropriate mitigation responses requires information on the costs of mitigating versus associated damages for the two levels...

Abstract To reduce the risks of climate change, governments agreed in the Paris Agreement to limit global temperature rise to less than 2.0°C above pre-industrial levels, with the ambition to keep warming to 1.5°C. Charting appropriate mitigation responses requires information on the costs of mitigating versus associated damages for the two levels...

Sorghum production in Burkina Faso relies on small scale farmers. Unfortunately, many suffer from drought caused by erratic rainfall during the rainy season. The importance of understanding farmers' perception on impact of drought and different ways to manage it is necessary. Participatory rural approach (PRA) using a focus group discussion and sem...

Better defining niches for the photoperiod sensitive sorghum (Sorghum bicolor L. Moench) varieties of West Africa into the local cropping system might help to improve the resilience of food production in the region. In particular, crop models are key tools to assess the growth and development of such varieties against climate and soil variability....

For most biophysical domains, differences in model structures are seldom quantified. Here, we used a taxonomy-based approach to characterise thirteen rice models. Classification keys and binary attributes for each key were identified, and models were categorised into five clusters using a binary similarity measure and the unweighted pair-group meth...

Climate change is expected to impact global food supply and food security by affecting growing conditions for agricultural production. Process-based dynamic growth models are important tools to estimate crop yields based on minimum inputs of climate, soil, crop management, and crop cultivar parameters. Using region-specific cultivar parameters is c...

To mitigate the effect of rainfall uncertainty in Sahel and to adapt to droughts during the growing season we propose to manage fertilizer application according to climate information and forecasts. Modeling crop responses can help to face climate change effects by developing fertilizers recommendation based on rainfall patterns. The crop model CER...

The agroecological zones (AEZ) of Mali fall within the semi-arid climate, the ability to determine efficiently or predict accurately the onset of growing season (OGS), and length of growing season (LGS) cannot be over-emphasized due to highly variable rainfall pattern and the dependence of smallholder farmers practising on rainfed farming agricultu...

Many simulation studies have been carried out to predict the effect of climate change on crop yield. Typically, in such study, one or several crop models are used to simulate series of crop yield values for different climate scenarios corresponding to different hypotheses of temperature, CO2 concentration, and rainfall changes. These studies usuall...

Uncertainties in predicting rice yield by current crop models under a wide range of climatic conditions Abstract Predicting rice (Oryza sativa) productivity under future climates is important for global food security. Ecophysiologi-cal crop models in combination with climate model outputs are commonly used in yield prediction, but uncertainties ass...

Predicting rice (Oryza sativa) productivity under future climates is important for global food security. Ecophysiological crop models in combination with climate model outputs are commonly used in yield prediction, but uncertainties associated with crop models remain largely unquantified. We evaluated 13 rice models against multi-year experimental...

Potential consequences of climate change on crop production can be studied using mechanistic crop simulation models. While a broad variety of maize simulation models exist, it is not known whether different models diverge on grain yield responses to changes in climatic factors, or whether they agree in their general trends related to phenology, gro...

Potential consequences of climate change on crop production can be studied using mechanistic crop simulation models. While a broad variety of maize simulation models exist, it is not known whether different models diverge on grain yield responses to changes in climatic factors, or whether they agree in their general trends related to phenol-ogy, gr...

Dans les mains des écophysiologistes, les caractères d'intérêt, résultant de l'interaction entre différents processus au sein de la plante et de l'interaction de la plante avec son environnement, sont décomposés en caractères élémentaires. La réponse de la plante à l'environnement est traduite en lois de réponse qui sont assemblées au sein de modèl...

The impacts of elevating CO2 and temperature on rice production must be quantified for designing appropriate adaptation and mitigation strategies to improve rice production under climate change. Crop models are the tools to quantitatively evaluate the impacts. However, the quantification of the impacts may not be consistent with each other among cr...

Cropping system models are powerful tools for regional impact assessment, but their input data requirements for large heterogeneous areas are difficult to fulfil. Hence, the objectives of this paper are to present low-data approaches for specifying detailed management data required by cropping system models, and for calibrating default crop paramet...

Crop simulation models are widely applied at large scale for climate change impact assessment or integrated assessment studies. However, often a mismatch exists between data availability and the level of detail in the model used. Good modelling practice dictates to keep models as simple as possible, but enough detail should be incorporated to captu...

Crop models require different structures for different applications. Modular and flexible crop modelling frameworks, such as the recently developed agricultural production and externalities simulator (APES), support the change of model structure. However, the assembly of different modules to create a model may not always result in the best model st...

Crop simulation models are widely applied at large scale for climate change impact assessment or integrated assessment studies. However, often a mismatch exists between data availability and the level of detail in the model used. Good modelling practice dictates to keep models as simple as possible, but enough detail should be incorporated to captu...

This thesis is an account of the development and use of a framework to introduce flexibility in crop modelling. The construction of such a framework is supported by two main beams: the implementation and the modelling beam. Since the beginning of the 1990s, the implementation beam has gained increasing attention in the crop modelling field, notably...

Crop growth models are used for a wide range of objectives. For each objective a specific model has to be developed, because the reusability of a model is often limited by the necessity of a fundamental restructuring to adapt it to a different objective. To overcome this limitation, we developed a method to facilitate model restructuring by a novel...

The process of crop modelling to develop operational software requires different skills, from conceptual-ization of the biophysical system to computer programming, involving three main scientific disciplines: agronomy, mathematics, and software engineering. Model building implies transforming a conceptual model into sets of mathematical equations a...

Autres auteurs : G. Bellocchi, J.-E. Bergez, M. Botta, E. Braudeau, S. Bregaglio, L. Carlini, E. Casellas, F. Celette, E. Ceotto, M.-H. Charron-Moirez, R. Confalonieri, M. Corbeels, L. Criscuolo, P. Cruz, A. di Guardo, D. Ditto, C. Dupraz, M. Duru, D. Fiorani, A. Gentile, F. Ewert, C. Gary, E. Habyarimana, C. Jouany, K. Kansou, R. Knapen, G. Lanza...

Development and use of crop models has become an interdisciplinary field with the increase on one hand of the biophysical knowledge and the development of numerous dedicated software platforms on the other hand. This trend calls for formalizing the integration of the disciplinary contributions of scientists having different expertises needed in cro...

Although existing simulation tools can be used to study the impact of agricultural management on production activities in specific environments, they suffer from several limitations. They are largely specialized for specific production activities: arable crops/cropping systems, grassland, orchards, agro-forestry, livestock etc. Also, they often hav...

Whereas it is recognized that management of plant diversity can be the key to reconciling production and environmental aims, most grassland models are tailored for high-value grass species. We proposed to adapt a mono-specific grass model to take into account specific features of species-rich permanent grasslands, especially over the reproductive p...

The Agricultural Production and Externalities Simulator is a modular simulation system targeted at estimating the biophysical behaviour of agricultural production systems in response to the interaction of soil-weather and different options of agro-technical management. APES is currently meant to be used at field scale, simulating 1-D fluxes (future...

The use of components to construct simulation models has many advantages and the technique is being used by many authors. However, in agro-ecological simulation there are some practical problems relating to the occurrence of circular dependencies between components and to tightly linked components. The objective of this paper is to present practica...