Authors: Océane Schaub, Anne-Pia Marty, Loukas Garanis, Marcelo Veloso



There are some new things cookin’ in the CrowdSoil world! Let’s go!

First of all, we had some very promising news from the HEIG-VD. We met with Pr. Jens Ingensand, teacher of Geoinformatics, and he will be proposing our app as a project for his students to code. Hopefully, if a student is interested, we will have a working prototype next semester!

In light of this news, we would like to take the opportunity of this blogpost to introduce you to the school part of our project. Indeed, one of our main target audiences are students aged 10-15. The goal is to organize a 6-session long workshop on soil and biodiversity, during which our app will guide the students through a series of tests and discussions.

We designed this application so that the teacher can have a theoretical and practical support at the same time. However, it is also possible for the teacher to use it only once, at any stage of the workshop, to introduce or exemplify a theme. It is thus possible to juggle between the various protocols and to follow one theme rather than another depending on the interest and knowledge of the students. In science, the ecosystem (plants, insects, animals) and the cycle of life will be introduced and / or deepened. The whole application is based on the system of the scientific approach. Students will be asked to observe, collect data, formulate a hypothesis, test this hypothesis, analyze the test results and then draw a conclusion.

Unfolding

The workshop takes place on 6 sessions of 1h30. Sessions can be daily, weekly, or irregular. Each week, the teacher begins with “In the previous episode …”, a brief reminder of what was done last week and why. This will refocus students on the framework and purpose of the experiments.


Session 1

This session is theoretical (in class).

[45min] The teacher establishes a link between the theory seen during the year and the usefulness of going to the field and putting the hands “to the ground”. It is a question here of transmitting to the students in a rather detailed way the historical context of soils (agricultural revolutions, massive use of pesticides, soil destruction, plowing, etc.) in order to initiate a critical reflection related to the need of better understanding the soil and its biodiversity.

[45min] After making this link, he introduces the application to students by browsing and showing them a tutorial / video presentation. The students are then divided into 5 groups. Then it would be nice for the teacher to show the plots / land that the students will be studying during the workshop. Students can begin to use the application by completing the first part of the study which focuses on the history of the land concerned (place, name, if there was perhaps a castle or a plant at the time, etc.), according to the information given by the professor.

Session 2

That’s it! We leave for the field!

This session represents the first contact with the earth!

[45min] The first part is mostly based on observation. This is the first session where students begin to get used to using their senses to analyze the environment: colors (soil, landscape), smells, temperature, sounds, weather, type of plants, stones. Students will also have to literally put their hands in the ground to make a first observation: earthworms? Smell, color? Roots? Students will be guided (but not too much) by the application during this process. They will note all their observations.
[45min] The second part of the session is dedicated to the discussion and the formulation of hypotheses. Students discuss with each other and with the teacher by comparing their results. Using the theoretical content provided by the application and the observations made, the students will make assumptions about:
• Why is this land like this?
• Why does he have this color?
• Why is this noise, or why the absence of an expected noise (singing of birds) ?
• What kinds of insects are present in the earth?
• What kinds of plants are present and why?
• What would happen if …?

The hypotheses direct the rest of the search. Depending on their interests, students will be able to pursue the study according to three branches / areas of interest: Germination (life cycle), Ecosystem (animals, insects and plants) and Soil structure (composition). Students write their assumptions about the application.

Session 3, 4, 5 and 6

In order to confirm or refute their hypotheses, students will have to perform one or more protocols (tests). Depending on which branch the students followed, the tests for this session will be different. Of course, students will eventually go through the majority of branches and perform the majority of tests. Indeed, all branches are intrinsically linked; the study of soil and biodiversity must take into account all the different facets of this environment. It is simply a matter of following the interest of the student.

A test corresponds to a session. After each test, the students must discuss, compare their results, discuss, and formulate hypotheses with the content provided by the application and by the teacher. To test these hypotheses, the application will offer students other protocols that they can try at the next session.

• Branch “Ecosystem”

1st test: Students can choose between different routes. If students are interested in insects, they may perform a Barber trap (http://biodiversite.ac-clermont.fr/documents/tech_study/barber sampling.pdf) to determine the composition of terrestrial carabidean communities, which are bio-indicators of the state of ecosystems.

2nd test: If, on the other hand, students are more interested in plants, they can start to identify bio-indicator plants, their number, etc. Spontaneous flora - what are wrongly called “weeds” - is a very good indication of the nature of a field! Simply by agreeing to live there - or not, to be dominant - or very rare, each species is a concentrate of information on the past and present life of a piece of land (https://more.groww.fr/ plants-bio-indicators / and https://www.visoflora.com/index.php?prop201=0&prop4=0&prop6=0&prop7=3&prop8=0 & component = guide & task = identifie & idEG = 59).


• Branch “Soil structure”

If students are interested in the land itself, they can move to the “Soil Structure” branch. The tests to be carried out will be the spade test, the flange test and the “Beer Can Test”.

1st test: The spade test is simple, fast and effective. It is simply a case of digging a spade or shovel into the ground about 30 cm deep. Then you have to take out the block of earth and examine it. Several things are worth noting in the app. The number of horizons (different layers of soil), the structure (porous, compact), the size of the aggregates, the difficulty to break these aggregates, the presence or absence of earthworms / roots, etc. Students will then assign a grade from 1 to 5 to the soil sampled on a specific scale (https://www.vd.ch/fileadmin/user_upload/themes/environment/sol/file_pdf/GEO_DE_SOLS_VESS_A_score_chart_EN.pdf). The spade test makes it possible to quickly have a good indication of the health of the soil. The test of the pudding, it is to take a little earth and roll it between his hands, trying to make a pudding. The shape of the pudding will indicate the presence more or less marked clay.

2nd test: The other test to be carried out in this branch is the “Beer Can test”. This protocol makes it possible to determine in a simple but scientific way the degree of porosity of a soil, thanks to an empty can. This will give students valuable insights that they can then use to formulate their next hypotheses.

• Branch “Germination”

This orientation is a bit special, as it will allow students to observe the growth of a plant, and therefore, the life cycle. Indeed, a first very relevant indication of the health of a soil is simply to know if the plants will grow in it. If they do not grow, why? Earth too acidic? Too clay? Too sandy? All these characteristics can be determined through several tests. In this branch, students will first have to bring back a seed and a little soil in the classroom, possibly during the first outing.

1st test: The pH test is to be done in class. For this test, one of the sessions will be held in class for all students. The purpose of the red cabbage test is to precisely determine the pH of a soil. The protocol to follow can be found at the following address: http://wiki.scienceamusante.net/index.php?title=Jus_de_chou_rouge.

2nd test: The test of the jar him, allows to obtain the composition of the soil, in percentage of sand, clay and silt, the three components most frequently found in the Swiss grounds. The protocol is available at this address: https://www.youtube.com/watch?v=nx8b80PmNE4.