Faire découvrir le sol aux élèves de primaire et à leurs professeurs : un exemple de pédagogie par projet

National audienc

Andosolisation dans les Hautes Vosges : conditions de développement et comparaison avec les autres processus de pédogenèse

During the last few years, the Andosol concept has undergone significant modifications leading to the setting up of new definition and classification rules by the international commissions. In the Vosges mountains, where some soils with andic features have been studied in the past, the use of these criteriacoupled with a field survey shows the presence of Andosols. The limiting factors and the necessary conditions for andosolisation in the Vosges, where brunification and podzolisation usually prevail, have been established by a precise characterisation of these soils, a study of the processes occuring withinthem and a comparison with other soils from the Vosges or with Andosols from other areas. Andosols from the Vosges have low contents of allophanes and high amounts of stable and immobile organo-metallic complexes, but they show a weak stage of development and the y cover only a small area. Andosol formation needs the union of favourable climatic conditions and parent rock: theformer can only be found in the highest parts of the moutains, where humid conditions allow mineral weathering and cold temperatures reduce the mineralisation of organic matter by biological activity. In such environments, andosolisation needs basic rocks with high amounts of weatherable mineraIs. Thechemical composition of the parent rock appears to be the main factor governing pedogenesis. The development stage of the process is mainly governed by the rock's texture, mineralogy and compactness. The absence of loose pyroclastic materials rich in glass can explain some particularities of this andosolisation : weak development and absence of allophanes.Le concept d'Andosol a subi, durant ces dernières années, une profonde évolution conduisant les commissions internationales à adopter de nouvelles règles de définition et de classification de ces sols. Un inventaire de terrain et l'application de ces critères dans le Massif Vosgien, ou des sols à caractères andiques avaient été signalés autrefois, aboutissent à la mise en évidence de l'existence d'Andosols. La caractérisation précise de ces sols, l'étude de leur fonctionnement actuel ainsi que des comparaisons avec d'autres sols vosgiens et avec des Andosols d'autres régions, permettent de déterminer les conditions nécessaires et les facteurs limitant au développement du processus d'andosolisation dans ce massif montagneux ou dominent habituellement brunification et podzolisation. Les Andosols vosgiens à peu près dépourvus d'allophanes sont riches en complexes organo-métalliques stables non mobiles mais leur degré d'évolution ainsi que leur extension géographique demeurent modestes. La formation d'Andosols exige la conjonction de conditions climatiques et de roche mère favorables : les conditions climatiques humides propices à l'altération des minéraux et froides affaiblissant l'activité biologique minéralisatrice des matières organiques ne peuvent être rencontrées que dans les parties les plus élevées du massif. Dans de tels environnements, l'andosolisation nécessite la présence de roches mères basiques riches en minéraux altérables. La composition chimique de ces roches apparait comme principal responsable de l'orientation de la pédogenèse. Sa texture, sa minéralogie, sa compacité sont déterminantes dans le degré de développement du processus. L'absence de matériaux pyroclastiques vitreux meubles explique certaines particularités de cette andosolisation : faible développement et absence d'allophanes

Helping Future Schoolteachers Discover and Teach Soil: An Example of Project-Based Learning

International audienceIn addition to fundamental knowledge, the teaching provided at primary school develop children's perceptions of the world, particularly that of the effects of human activities on the environment. However, despite its importance in these issues, soil is virtually absent from school curricula, and even more so from the training of future schoolteachers. In order to provide knowledge about soil and its crucial role in the challenges facing humanity, an educational project has been developed at the University of Lorraine for students on the multidisciplinary bachelor's degree in teaching course during the past 5 years. Over fifty students follow traditional soil science courses and then use their knowledge in an activelearning setting. Within the framework of a project-based learning, they organize and carry out an activity session focusing on soil in a class of elementary school pupils, which is a kind of practice for their future teaching careers. The students follow the different stage in building their project. They design their workshop around a soil-linked theme of their choice, respecting the curriculum expectations. They establish a scientific approach to the chosen question and draw up the timetable for their activity, specifying the learning objectives and the resources to be used. They then carry out their activity session with a class at a partner school. The project is assessed on the basis of the students' concrete achievements, as well as their effective analysis of their work. This type of project-based teaching engages students because it gives them the opportunity to take ownership of the discipline through the production of a tangible output. Building and then carrying out the activity session helps to develop students' independence, creativity, and teamwork while at the same time imposing a framework that they must respect. It also enabled them to create a good quality animation, even though for most of them this was their first introduction to the subject of soils

Un voyage à travers le sol. Récit d’une animation destinée à faire découvrir la pédologie aux scolaires et au grand public

International audienceSoils. The public education about the crucial ecosystem services ensured by soils and the promotion of sustainable management andprotection of soil resources are among the specific objectives of the UN resolution. For this purpose, the “Fête de la science” event,supported by the French Ministry of Education, provides an appropriate framework for the creation of an educational activity named “Ajourney through the soil”. The aim of this workshop is to contribute to a better knowledge of soils by pupils (from local schools) and bya non-scientific audience. The student volunteers (Bachelor or Master degree) of the Lorraine University (Metz location) and the authorshave created the various activities proposed in the workshop, and are both still involved in workshop facilitation since 2015.Organized in four themes (table 1), the workshop guides pupils through a travel within the soil (figure 1). In the first theme (figure 2),students discuss with pupils to define soil by asking questions (what is a soil? the floor of the classroom? the garden soil?) and clarifythem with posters. Theme 2 corresponds to the soil components and organization (figure 3), which are studied by various experiments(HCl test, soil texture by feel) or observations (thin section). The observation of soil living organisms (figure 4) in theme 3 allows explainingtheir role in organic matter recycling and illustrates soil biodiversity. Finally, the last theme (figure 5) shows services provided by the soiland threats affecting its quality through a game where pupils place objects related with services or threats on a carpet representingvarious soil environments.For the last four years, the workshop “A journey through the soil” has received about 750 pupils, 250-300 persons during the wideaudience action, both under the supervision of 30 students. Experimentations are pupils’ favorite activities, while adults prefer to debatewith the workshop coordinators (students or authors). Students have enjoyed working with children. Furthermore, their involvement inthis workshop allows them to practice soil science and develop their skills in public speaking or group facilitation. Finally, this workshopmay evolve according to current issues concerning soils and environment.Creado durante el año internacional de los suelos en 2015, el taller pedagógico “viaje a través de los suelos” se pensó para promoverel estudio de los suelos ante un público diverso, desde alumnos de primaria hasta el gran público. Este taller se declina en cuatrotemas: un primer tema aborda la noción de definición del suelo vía un juego de cuestiones-repuestas entre el animador del taller y elpúblico. Gracias a observaciones o a pequeñas experiencias, el segundo tema se interesa a los diferentes constituyentes del sueloy a su organización, y el tercero tema a los organismos vivos en el suelo y a sus funciones. En fin, el último tema se centra sobre losservicios prestados por el suelo y los peligros que lo amenazan, por medio de una animación en torno a objetos que simbolizan estasnociones. Desde 2015, este taller recibe alumnos de ciclo 3 de las escuelas del departamento de Mosela en dos días y el gran públicoen un día. El taller está animado por los autores y los estudiantes voluntarios de las formaciones de la Universidad de Lorena (sitio deMetz). Si las manipulaciones diversas (suelo, organismos, química…) son muy apreciadas por los niños, el público adulto prefiere másbien discutir con los animadores de grandes desafíos ambientales que conciernen los suelos (cambios climáticos, impermeabilización,contaminación...). Este taller es igualmente la ocasión, para los estudiantes que lo encuadran, de desempeñar sus competencias tantoen pedología que en animación y en pedagogía. En fin, se concibió el taller “viaje a través del suelo” para poder cambiar cada año y asíintegrar mejor las preguntas de actualidad y los desafíos societales que conciernen los suelos.Créé lors de l’année internationale des sols en 2015, l’atelier pédagogique « Voyage à travers le sol » a été pensé pour promouvoir l’étude des sols auprès d’un public varié, des élèves de primaire jusqu’au grand public. Cet atelier se décline en quatre thèmes : un premier thème aborde la notion de définition du sol via un jeu de questions-réponses entre l’animateur de l’atelier et le public. Grâce à des observations ou à de petites expériences, le deuxième thème s’intéresse aux différents constituants du sol et à son organisation, et le troisième thème aux organismes vivant dans le sol et leurs fonctions. Enfin, le dernier thème est centré sur les services rendus par le sol et les dangers le menaçant, au moyen d’une animation autour d’objets symbolisant ces notions. Depuis 2015, cet atelier reçoit des élèves de cycle 3 des écoles de Moselle sur deux journées et le grand public sur une journée. L’atelier est animé par les auteurs et les étudiants volontaires des formations de l’Université de Lorraine (site de Metz). Si les manipulations diverses (sol, organismes, chimie…) sont largement appréciées par les enfants, le public adulte préfère plutôt discuter avec les animateurs des grands enjeux environnementaux concernant les sols (changements climatiques, imperméabilisation, pollution…). Cet atelier est également l’occasion, pour les étudiants qui l’encadrent, d’exercer leurs compétences tant en pédologie qu’en animation et en pédagogie. Enfin, l’atelier « Voyage à travers le sol » a été conçu pour pouvoir évoluer chaque année et ainsi intégrer au mieux les questions d’actualité et les enjeux sociétaux concernant le sol

A trip through the soil to raise public awareness

International audienceCreated specifically for the International Year of Soil, a pedagogical project focused on soil has been developed by the University of Lorraine, and since regularly renewed. The aim of this project is to elaborate an educational activity about soils, through observations and experiments designed for a young audience and for a general public.Therefore, the authors and students from bachelor and master levels have jointly developed this activity and make it evolve every year. Students had thus the opportunity i) to practice and improve their knowledge about soil sciences, and ii) to debate about teaching methods and sharing their knowledge with different people (public, schoolchildren). This kind of active learning is regarded as one of the effective educational methods (Field et al., 2011).This educational activity has been built as a trip to explore different aspects of soils. Students drive pupils from primary school toward different stands where they can observe soil biodiversity, experiment on soil composition, learn about soil properties and functions (soil retention, biodegradation…). The session end with a discussion on some of the essential services provided by soils and their protection.For the general public session, people are free to switch from one stand to another, while students and authors answers to their questions and initiate debates. Since a few years, a special activity is proposed in relation with the World Soil Day theme. This project is a good opportunity to promote the role of soil to a large audience, from children to students and general public

Effets du pH du sol sur le test de génotoxicité Vicia-micronoyaux

International audienceFace à la multiplication des sites et sols contaminés, il est nécessaire d’apporter une solution technique pour évaluer le potentiel génotoxique des sols. En effet, il n’existe actuellement aucun test normalisé au niveau international pour mesurer la génotoxicité (toxicité vis-à-vis du matériel génétique) des matrices solides par exposition directe. La normalisation ISO du test Vicia-micronoyaux nous a amenés à travailler sur l’effet du pH sur la fréquence des micronoyaux ainsi que la gamme de pH dans laquelle le test est réalisable. Deux approches ont été envisagées: la modification artificielle du pH d’un sol et l’exposition à des sols de pH naturellement différents. Les résultats montrent que le test peut être réalisé en respectant les critères de validité dans une gamme de pH allant de 3,1 à 9,0 sans observer d’augmentation de la fréquence des micronoyaux. Les tests réalisés avec les sols naturels de pH différents confirment ces résultats

Effects of soil pH on the Vicia-micronucleus genotoxicity assay

International audienceIn the field of contaminated sites and soil management, chemical analyses only bring typological data about pollution. As far as bioavailability and effects on organisms are concerned, we need ecotoxicology tools. In this domain, among many existing tests, we chose to study genotoxicity because it is a short-term endpoint with long-term consequences. The aim of this study is to assess the effects of soil pH on the results of the Vicia faba root tip micronucleus test for the two following reasons: (i) to define the pH range within which the test can be performed without modifying the soil to be tested, within the framework of the ISO standard of the test and (ii) to provides information about the effects of the pH on the genotoxic potential of soils. In this context, we modified the pH of a standard soil with HCl or NaOH and we spiked the matrix with copper (2, 4 and 8 mmol kg(-1) dry soil) or with maleic hydrazide, an antigerminative chemical (5, 10 and 20 μmol kg(-1) dry soil). We concluded that the pH had no effect on the mitotic index or micronucleus frequency in the root cells of the negative controls: extreme pH values did not induce micronucleus formation in root cells. Moreover, according to our results, the Vicia-micronucleus test can be performed with pH values ranging between 3.2 and 9.0, but in the ISO 29200 "Soil quality--assessment of genotoxic effects on higher plants--V. faba micronucleus test" we recommended to use a control soil with a pH value ranging between 5 and 8 for a more accurate assessment of chemical genotoxicity. We also found that acid pH could increase the genotoxic potential of pollutants, especially heavy metals. With hydrazide maleic spiked soil, plants were placed in a situation of double stress, i.e. toxicity caused by extreme pH values and toxicity induced by the pollutant

PromoSolsEduc: a tool for identification and valuation of educational resources on soil knowledge and preservation

International audienceThe french branch of the International Union of Soil Science, the ‘Association Française pour l’Étude du Sol’ (AFES) is a national society which aims to share knowledge about soils in order to contribute to the protection of this crucial resource. Among the various activities undertaken by AFES, the PromoSolsEduc project gathers and shares teaching material to improve soil education.The PromoSolsEduc project brings together a community of more than 80 scientists and teachers involved in the development of good practices in soil science education, through a network where they can discuss their experience, exchange on difficulties encountered and share solutions. This initiative is based on a multidisciplinary working group comprising members of AFES Board, soil researchers and engineers from various structures, teachers and soil education specialists.The first step was to compile, but also to evaluate existing resources (books, videos, web sites…) and to develop a search engine on the AFES’s website, allowing easier access to this material. In a second phase, a survey was conducted among education institutions, showing the great diversity of teachers engaged in the transfer of knowledge in soils sciences. Furthermore, this investigation revealed the specific needs of teachers, such as scientific support in order to access more efficiently complete and reliable teaching materials. This works led to a dynamic mapping of the key resource people in soil education. A new step has recently been reached with an interactive workshop where teachers pointed out difficulties, helping the AFES Board to plan future improvements of its website