Soil Science Archives - Eva Varga

March 1, 2016

As we become for technologically advanced and our urban cities grow, I believe it is increasingly important for our youth to have an understanding of where our food comes from – both historically and today.

Whether you live in Atlanta or rural Nebraska, in the mountains or along the coast, engaging students in real world experiences and developing an awareness of agricultural practices is not difficult. There are many free teaching resources available for educators of all ages.

By encouraging teachers to integrate agriculture into their classroom via authentic, core curriculum concepts, Agriculture in the Classroom partners have collaborated to cultivate an understanding and appreciation of the food and fiber system that we all rely on every day.


An agriculturally literate person is defined as “one who understands and can communicate the source and value of agriculture as it affects our quality of life.”

Take some time to explore the variety of resources available – I share a few of my favorites below. You can put together an entire semester course or pick and choose a few lessons to augment your current studies.


Plant & Animal Science

Agriculture has traditionally been defined by the production of plants and animals. Today, science and technology have added new areas of research, and investigation to the agriculture field.

agricultureExtension 4-H professionals have developed a wealth of curriculum materials and a variety of hands-on agriculturally based activities to promote agricultural literacy among young people. Much is available for free but some curriculum modules are available for purchase.

Soil Science

To help educate students about the important role soil nutrients play in feeding our world, the Nutrients for Life Foundation sends out a monthly newsletter that will provide you with new ideas and tips for teaching plant and soil science while providing creative activities to bring into your classroom. They have also developed numerous modules for elementary, middle and high school classrooms to provide STEM activities and lessons.

soilscienceSoil Science Reader :: A digital science journal specifically designed for grades 7-8 (graphics and photographs capture interest) introduces soil formation and soil horizons with a fun edible soil activity. Other topics include the nitrogen cycle, plant nutrition, and fertilizer basics featuring the 4R Nutrient Stewardship.

Soil Reader :: Written specifically 5th & 6th grade students, this 18-page digital journal features an interview with an agriculture engineer and features puzzles, quizzes, and visuals to enhance a teacher’s soil unit.

For complete curriculum, posters, games, flashcards, and much more – visit the Nutrients For Life webstore. Everything is FREE!!

Invasive Species

Hundreds of invasive plants and animals have become established across the country and are rapidly spreading each year. These invaders are negatively impacting our waters, our native plants and animals, our agriculture, our health, our economy, and our favorite recreational places.

Prevention is the most effective strategy in managing invasive species. To increase public awareness of invasive species issues and promote public participation in the fight against invasive species and their impacts on our natural resources, the California Department of Fish & Wildlife have developed curriculum and materials available free to schools and educators.invasivespecies

Stop the Invasion :: Students will learn about six different invasive species, the damage they cause, and how to stop their spread.

If you reside in California, you may also be interested in the community action week with events across the state and a youth art contest. Similar programs may exist in your state. Contact your local department of fish and wildlife or county extension agency to learn more.

May 16, 2015

Mud, or sediment, is an active part of aquatic ecosystems. Sediment varies widely within and among ecosystems in its biotic and abiotic characteristics.

Biotic factors are the living components of a community or larger ecosystem.

Abiotic factors are essentially non-living components that effect the living organisms of a community.

In many ecosystems sediment can release excess phosphorus (a common aquatic pollutant) into the water column causing internal eutrophication.

When studying aquatic ecosystems, people often think about the water and things that live in the water. However, the mud at the bottom of lakes and wetlands – the sediment – is an active part of these ecosystems. A wide diversity of organisms, both macroscopic and microscopic, live in sediments.

Sediments can often be a source of nutrients, especially nitrogen and phosphorus. Nutrients released from sediments are part of an ecosystem’s internal load (as opposed to the external load, which consists of nutrients that come from outside the  ecosystems).

Most commonly, sediments release large amounts of phosphorus as phosphate, sometimes causing excessive algal growth, harmful algal blooms (growth by algae that produce toxins), and even fish kills (as dead algae fall to the bottom of an ecosystem, fuel bacterial decomposition, and consume oxygen). These negative effects caused by sediment release of phosphorus are called internal eutrophication.

STEM Club: Life in the Mud @EvaVarga.netLife in the Mud

Gather around a picnic table at a local pond or wetland area. Lead the class in a discussion about how the abiotic and biotic components of the pond could interact. Use what the students have said to link the nutrient content of the sediment and water to the activity of living things in the water. For example, nutrients released from the sediment can enhance growth of algae in the water.

Ask students to hypothesize about what they expect to see in the mud. What makes up the sediment? What makes up the pond water? Describe some possible interactions between the sediment and the water column.


  • 2 quart jars with lids for each group
  • Mud from a pond (enough for about 1/3 of each of the jars)
  • Water from a pond–algae WILL be there (enough to fill the other 2/3 of each of the jars)
  • Shovel (one for each group)
  • Water quality kits for measuring nutrients for each group
  • Compound microscope (for each pair of students)
  • Microscope slides
  • Optional Materials: Dissolved oxygen meter, dissecting microscope, thermometer, conductivity meter, funnel

STEM Club: Life in the Mud @EvaVarga.netExperimental Set Up

  1. Split into small groups and distribute materials evenly. Each group should disperse to a different area around the pond perimeter to begin the experimental set up.
  2. Each group should utilize the water quality kit to test the pond water and record the data in their journals.
  3. Each group sets up the jars: one with nothing but pond water in it (control group) and another jar with 1/3 pond sediment and 2/3 water in it (treatment).
  4. After collecting mud samples, return to the table. Lead students through the process of developing a hypothesis with the guiding questions: What differences do you expect to see in the treatment group and control group in about a week? Why do you think those differences might occur? Possible hypothesis: There will be a greater number of algae in jar with sediment and pond water compared to the jar with only pond water.
  5. Check the jars after one week. If you do not see obvious responses, check them again after two weeks as it may take some time for visible algal growth to occur.

Data Collection

  1. Qualitative Observations: appearance of the water and sediment, look for evidence of algae growth—cloudy water and green “slime” on the sediment; any bubbles coming from the sediment, smell, layers in sediment evidenced by color difference or texture changes; macroscopic organisms in either sediment or water; bacterial growth (slime).
  2. Quantitative Observations: use a microscope to count the algal cells in the water in each jar; if available, test the water in each jar with any available nutrient water testing kit (nitrogen and/or phosphorus), depth of water and sediment over time, water temperature, conductivity and dissolved oxygen, pH.

If you would like to do undertake this outdoor lab activity with you students, I’ve created a free printable student page, Life in the Mud, for your use. If you download it, please leave a little note in the comments.