Surprising Facts About Soils, Students and Teachers! A Survey of Educational Research and Resources

Abstract

Soil is one of the key resources that sustain life on Earth, not just as the foundation for almost all our food supplies, as important as that is, but also in the way that it filters water, supports biodiversity, and perhaps even moderates global climate. Yet the world’s soils are under increased pressure on many fronts. They face unprecedented threats from erosion, deforestation, desertification, salinization, sealing (paving over), contamination, loss of biodiversity, and climate change. The importance of soil and the need to sustain it against these threats, however, have elicited little interest, not only by scientists and the general public, but also by the educational systems of most countries. While increasing attention has been paid to other important environmental topics, such as loss of biodiversity, climate change, deforestation, fresh water availability, and the world’s oceans, little attention has been placed on soil so far.

A way of meeting this challenge that has been instituted in a few countries has been to include soil science, e.g. its concepts, concerns and protection, as a core topic in the country’s national science curriculum, so that from a young age students learn the key concepts of soil science and how and why people should protect soil in a sustainable way. The research surveyed in this article shows that elementary students as young as preschool have some initial ideas about the depth of soil and its usefulness in supporting plant growth, but have little understanding of its composition, formation, or origin. Middle school students, of 10–12 years in age, arrive at the topic with more understanding in some areas, such as the thinness of soil layers, but are still ignorant concerning its age and origin. After several weeks of hands-on activities combined with “minds-on” discussion, students as young as 5–6 years in age are able to get “soil on their mind,” as evidenced by the diagrams they draw before and after intervention, while students 10–12 years in age are able to understand the three-dimensional nature of soil, as well as start to understand its formation process and age.

Elementary teachers begin their profession understanding substantially more soil concepts than their students. Over 80% know that soil is formed by the weathering of rocks, that earthworms mix the soil and allow for more air and water to enter, and that decomposition provides soil nutrients for plants to grow. Very few of them, however, are aware of how many life forms there are in a handful of soil, how many years it takes for soil to form, how much of soil is space for air and water, which component of soil has the smallest particles, or what role humus plays. After two or three classes of intensive hands-on activities, they also are able to make substantial gains in their understanding, reducing by 33% what was lacking in their understanding of soil concepts. They can also make gains in their attitudes towards the need to protect soils, compared with other environmental challenges.

The little research that has been done with secondary students shows that their initial ideas about soils, and their ability to achieve a deeper understanding of soil through classroom activities, is similar to that of middle school students. No studies have reported on secondary school science teachers’ understanding of soil. Two studies with secondary school agriculture teachers indicate mixed results as to how prepared they are to teach soil science. This review concludes with a brief description of resources available for soils education, including equipment kits and unit manuals for elementary school, and journal articles, websites, and electronic resources for all grades. Given available soil education research and resources, this work suggests that the most important thing people concerned about soil education can do is advocate for the inclusion of soil science as a separate topic in their national elementary science curriculum, if that is not already in place.