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Les applications de la modélisation des cultures : une clé pour soutenir la sécurité alimentaire et pour recommander des adaptations durables et des stratégies de gestion raisonnables dans le cadre des systèmes de l’agriculture pluviale (cas de la culture du blé au Maroc).
No full textRainfed agriculture represents the central pillar of the world’s future challenges to ensure enough food and to generate adequate income to better feed the poor and hungry people. Under the rainfed conditions of Morocco, wheat cropping systems – the population’s basic staple food – are subject to a set of limitations that seasonally impact crop production and farmers’ incomes, thus national food security. In the last decades, the major constraints were often related to the country’s Mediterranean-type climate, through the intense recurrence of drought events and high inter- and intra-annual rainfall fluctuations. The frequency of drought events has increased five-fold in Morocco, going from one extreme event out of fifteen normal years during the 30s, 40s, 50s, 60s, and 70s, to one drought year out of three during the last two decades. Likewise, the various forms of soil degradation have also major impacts that impede wheat crop intensification and affect population livelihoods. An example of soil degradation is nutrient depletion resulting from inappropriate and unsustainable fertilization practices that fail to replace the nutrients extracted from agricultural products, along with nutrient losses due to soil erosion and leaching of chemical or natural fertilizers. As a result, the limitations on production often extend beyond environmental factors and also imply the inadequate crop management strategies adopted by farmers. In Moroccan rainfed areas, the crop production limitations linked to management practices are frequently attributable to small farmers' limited access to knowledge or financial constraints, what limits their capacity to implement effective strategies.
Advanced technologies such as remote sensing and crop modeling are crucial in assessing wheat cropping systems in Moroccan rainfed areas. Traditional experiments-based agronomic research struggles to comprehend the complex interactions between genotype, environment, and management (G×E×M). For this reason, crop modeling approaches offer significant advantages over conventional methods, including the ability to provide more accessible, rapid, cost-effective, and comprehensive insights into cropping systems. Furthermore, crop modeling approaches may have the potential to produce more accurate predictive knowledge and enhance our understanding of the status of cropping systems.
Our findings during this thesis project show the effectiveness of crop models to evaluate and improve wheat cropping systems under rainfed conditions of Morocco, through highlighting our contributions to the three primary themes (or missions) of crop modeling applications:
i) Preserving food security: The accurate predictive capabilities of empirical or mechanistic models play a critical role in monitoring crop growth and yield at the field level. Consequently, the application of these models provides a significant opportunity for improving seasonal crop yield forecasting and drought early warning systems in Moroccan rainfed areas. Furthermore, interpreting the core structure of crop models is instrumental in assessing the impact of external factors such as environmental conditions or farmers' practices on yield variability (i.e., yield gap assessment) at the field level.
ii) Supporting general adaptation strategies to face climate change effects and extreme events: Crop models can help to understand the climate change and extreme events effects on wheat system productivity under rainfed conditions. In this context, crop modeling works were
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conducted to evaluate the added values of new crop management strategies (e.g., no-till farming, rotation practice, genotypes selection programs etc.), and to propose general adaptations across a wide range of spatial and temporal scales (e.g., specific pedo-agro-climatic adaptations).
iii) Recommending within-season and field level crop management advice: The use of mechanistic models, such as APSIM-wheat in this study, allows capturing the impacts of climate variability and specific crop management practices at within-season and field level. Our study highlights the effectiveness of these models as decision support tools for recommending optimal crop management practices, particularly with regards to N and P fertilizer application in Moroccan rainfed agriculture.SoilPhorLife-Projet413. Climate actio
Modeling genotype × environment × management interactions for a sustainable intensification under rainfed wheat cropping system in Morocco
No full textUnder the conditions of Moroccan rainfed agricultural areas, wheat cropping systems—the population’s basic staple food—are subject to a set of limitations that seasonally impact crop production and farmers’ incomes, thus national food security. In the last decades, the major constraints were often related to the country’s Mediterranean-type climate, through the intense recurrence of drought events and high inter- and intra-annual rainfall fluctuations. Similarly, various forms of soil degradation inhibit the potential of this slowly renewable resource to support wheat crop intensification and ensure livelihoods. However, the limitations sometimes surpass the environmental factors to implicate the inappropriate crop management strategies applied by farmers. In Moroccan rainfed areas, production problems linked to crop management practices result principally from a shortage in the provision of knowledge to Moroccan small farmers, or their indigent economic situation that limits farmers’ capacity to adopt, qualitatively and quantitatively, efficient strategies. Advanced technologies (remote sensing or crop modeling) play key roles in assessing wheat cropping systems in Moroccan rainfed areas. Due to the difficulties of using conventional experience-based agronomic research to understand Genotype × Environment × Management (G × E × M) interactions, the substantial benefits of crop modeling approaches present a better alternative to provide insights. They allow the provision of simpler, rapid, less expensive, deep, and potentially more accurate predictive knowledge and understanding of the status of cropping systems. In the present study, we highlight the constraints that surround wheat cropping systems in Moroccan rainfed conditions. We emphasize the efficiency of applying crop modelling to analyze and improve wheat cropping systems through three main themes: (i) preserving food security, (ii) supporting general adaptation strategies to face climate change effects and extreme events, and (iii) recommending within-season and on-farm crop management advice. Under Moroccan context, crop modeling works have mainly contributed to increase understanding and address the climate change effects on wheat productivity. Likewise, these modeling efforts have played a crucial role in assessing crop management strategies and providing recommendations for general agricultural adaptations specific to Moroccan rainfed wheat
Integrated effect of saline water irrigation and phosphorus fertilization practices on wheat (Triticum aestivum) growth, productivity, nutrient content and soil proprieties under dryland farming
No full textWheat (Triticum aestivum) is the most common and oldest crop in Morocco and MENA region countries, cultivated both for human and animal nutrition. In Morocco, the irrigated perimeter of Tadla is the major wheat growing area affected by soil and groundwater salinity problematic. Previous studies have shown that phosphorus (P) fertilization can mitigate the negative effects of salinity on different crops. Thus, field experiments from the combination of four levels of irrigation water salinity and three P-fertilization rates were conducted during two successive growing seasons (between 2019 and 2021) at the National Institute of Agronomic Research (INRA), Tadla, Morocco. Our main objective was evaluating the potential of P-fertilization to improve wheat growth, productivity and quality under saline water irrigation practices. The crop simulation model APSIM, was also tested to assess its performance in simulating wheat growth, productivity, phosphorus and nitrogen nutrient dynamics in soil-plant system under saline conditions. Results showed that appropriate P-fertilization under saline conditions contributed to minimize the effect of salinity and improved wheat growth and production. Also, it was found that increasing P-fertilization improved nutrient uptake, and consequently the plant nutrient content. A good agreement between the measured and APSIM model simulated growth and yield state variables, as well as the plant and soil-N content. However, a model uncertainty and relevant limitations in simulating plant- and soil-P content output were identified and discussed. Overall, our finding suggests that appropriate P- application minimizes the adverse effects of high soil salinity and can be adopted as a coping strategy in wheat cultivation under saline water irrigation practices
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Assessment Of Crop Simulation Models Performances In Simulating Crop Growth And Development Variables And Predicting Yield In Moroccan Rainfed Areas
No full textpeer reviewedCrop simulation models are valuable tools widely applied in various climatic conditions to evaluate and recommend the optimal crop management practices in order to improve crop production, specifcally for the rainfed crop production that is mainly affected by recurrent drought and blocked by low inputs of fertilizers and by disease and crop pests. Therefore, as part of a major objective focused on the application of two models to improve wheat management practices in Moroccan rainfed areas, the purpose of this research study is using a database of measured and observed wheat growth and production state variables to calibrate and evaluate CERES-wheat and APSIM-wheat models for the simulation of wheat growth and prediction of yield of ve wheat cultivars widely used in the Moroccan rainfed areas. During three crop seasons (from 2019 to 2021), crop management information, wheat growth state variables and grain yield were collected during critical growth stages of wheat development from more than 120 of farmers’ felds covering the main agro-climatic Moroccan rainfed areas. During calibration process, measured data of two successive crop seasons (2018 and 2019) were employed to estimate the models genetic coeffcients of the five studied cultivars. Independent data sets of 2021 crop season were used to evaluate APSIM-wheat model performances. Based upon validation process, in the comparison with measured and observed collected dataset, the two models simulate with good accuracies the wheat development stages,
above-ground biomass and yield for all cultivars, whereas, the models simulation have overestimate leaf area index values. After the acceptable results of the two wheat models performances in Moroccan rainfed areas, we made certain that these models will serve as valuable tools to be applicate in improving wheat management practices of Moroccan farmers, speci cally, fertilization advices
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