This contest invites young people to explore the hidden world beneath their feet. Urban soils may seem invisible, but they cool our streets, soak up rainwater, grow food, and sustain life: even in the tiniest cracks. Through fun, hands-on experiments, kids will become “urban soil detectives,” observing, testing and documenting their discoveries to uncover how soil shapes life in their neighbourhoods.

OBJECTIVES:

• inspire children to discover and value urban soils through exploration and play;
• raise awareness of the invisible roles soils play in cooling streets, absorbing water, growing food, and sustaining biodiversity;
• show how everyday urban spaces, pavements, parks, and gardens rely on healthy soils;
• connect soil science to children’s daily lives through simple, hands-on experiments; and
• encourage creativity, observation and curiosity about the hidden nature in cities.

PARTICIPANTS:

• children and youth worldwide aged between 8 and 15 years old;
• individual or group submissions are accepted (such as class projects, clubs or families); and
• each participant or team may submit one original “detective report.”

REQUIREMENTS:

• the format is a “detective report”, including:
• at least three completed soil experiments (see the section “EXPERIMENTS AND DETECTIVE MISSIONS”;
• photos, sketches and/or creative journals and notes as evidence; and
• optional extras: maps, charts or “detective clues”.
• the content should be engaging, creative and scientifically accurate, showing how soils shape city life;
• the content should be in English; and
• the report should be submitted as a PDF or Word document (maximum five pages per experiment).

SUBMISSIONS:

• the deadline for submissions is on 10 November 2025;
  
• submissions must be uploaded via the ONLINE REGISTRATION FORM
  
• files can be shared via a free transfer service (such as Google Drive, Dropbox or WeTransfer);

To help kids and teachers prepare their reports, we have created a simple template, just 👉🏿👉🏿👉🏿 download it, fill it in and submit it through the online form.

For questions: [email protected]

JURY

The IUSS and FAO’s GSP Selection Committee will evaluate submissions based on:

• creativity, originality and scientific soundness;
• alignment with WSD 2025 key messages on urban soils and healthy cities; and
• quality of documentation (photos, sketches, observations).

PRIZES AND RECOGNITION:

• All participants who complete at least three experiments will receive an electronic “Tiny Soil Detective” certificate.
• The top three winners will receive FAO publications and gadgets.
• The most creative and well-documented reports will be showcased during the WSD 2025 celebration (5 December) and promoted on FAO, GSP and IUSS platforms.

TIMELINE:

• submission deadline on 10 November 2025; and
• winners announced on 5 December 2025, during the official World Soil Day celebration.

TERMS AND CONDITIONS:

• Copyright remains with the authors and credit will be given accordingly.
• The reports must be the original work of the participant(s) and be previously unpublished.
• By submitting, participants consent to their reports being uploaded on FAO/GSP/IUSS digital platforms.
• FAO/GSP/IUSS do not endorse the views expressed by contestants.

EXPERIMENTS AND DETECTIVE MISSIONS

1. Heat spy mission:

• where: pavements, playgrounds and tree pits (where trees are planted by the pavement);
• how: compare surface warmth by touch, dropping water and seeing how long it takes to evaporate or using a thermometer;
• detective clue: Asphalt heats up fastest, while grass and soil stay cooler;
• city link: shows how green spaces help cool urban areas;
• evidence (required): share photos of your neighbourhood’s “hot spots” and “cool spots”; and
• optional: create a simple neighbourhood heat map.

2. Biodiversity in the pavement cracks:

• where: pavement cracks and at the base of walls;
• how: search for plants, insects or other tiny life in urban soils;
• detective clue: Even the smallest bit of soil supports life;
• city link: shows that soil and biodiversity thrive in unexpected places, even in pavement cracks;
• evidence (required): share photos of what you find in cracks; and
• optional: make a sketch of the “tiny jungle in the crack”.

3. The rainwater experiment:

• where: streets, gutters and park paths after rain;
• how: pour water on bare soil, grass, and concrete and see what happens;
• detective clue: Soil and grass absorb water, while concrete directs it away;
• city link: explains why floods are quicker to happen in paved areas; and
• evidence (required): share photos of your experiment.

4. The soil-to-table walk:

• where: farmers’ market, community garden or urban vegetable patch;
• how: ask growers/gardeners about the origin of the soil or take a small sample;
• detective clue: Cities rely on healthy soils nearby for food production;
• city link: urban agriculture supports food security;
• evidence (required): share photos of your visit or samples; and
• optional: draw the “journey of an apple” from soil to city.

5. Compost challenge:

• where: at home or school;
• how: collect fruit and vegetable scraps, make a mini compost in a bottle and watch the soil transform;
• detective clue: Organic waste can become fertile soil;
• city link: demonstrates recycling and urban soil regeneration; and
• evidence (required): share photos documenting the different compost stages. 

How to earn your certificate:
Take photos or videos of your experiments, sketches and notes. Share your evidence to demonstrate your work as a soil detective. Optional creative additions, like your “soil colour chart” or the “journey of an apple,” will make your map of the city’s soil even more exciting.