AgBC's: S is for Sensational Soil

Soil is so important, yet we hardly think about it! Soil anchors plant roots, holds water for plants, and even provides air spaces for plant roots to grow.

Image from the Extreme Pumpkin Store

But for all that, did you know soil is basically made of of 3 sizes of particles? Sand is the larges, clay is the smaller, and silt falls in the middle size-wise. The proportion of each of these particles varies from soil to soil, giving each soil unique characteristics. Some solid drain more quickly (sand), while others hold water or become saturated with water (clay). Many plants, trees and shrubs prefer to grow in a balanced mixture of these particles called "loam." Loamy soils hold a moderate amount of water, air and nutrients while supporting the plant.

A vineyard in Lake County, Ohio

Because characteristics of the soil can affect plant growth, farmers and gardeners often test soil to determine if it's good for growing specific plants. Two such simple tests include the ribbon test and the "soil shake" test. The results are a good predictor of whether or not the soil is good for growing specific plants. More accurate assessments can be sent to soil testing labs, and today it is increasingly common for farmers to have their cropland grid sampled and have the results of their soil testing GPS mapped to improve the efficiency of their farming operations.


Here are some simple instructions for conducting the ribbon and "soil shake" tests with your students:

• Ask the students if they've ever heard of the ribbon test. The explain that is can help determine what kinds of particles are in their soil. 
• Demonstrate the text by moistening a handful of garden soil or silt in the palm of your hand until it has the consistency of putty. Work the soil into a ball about 1/2" in diameter. Press the ball between your forefinger and thumb to form a ribbon (see below).
• If the soil will not form a ribbon, it is sand. If it makes a ribbon 1-2 inches long, it is loam. Ribbons longer and 2 inches are clay. Here is a more detailed description.
• Explain that each of the three types of soil particles forms a different type of ribbon. Repeat the test with clay and sand.
• Ask the children to describe the difference between the three ribbons.
• Pass out different kinds of soil without telling the students what soil type they have; let them each conduct their own ribbon test and hypothesize about what type of soil they have.

Making a soil ribbon.

Students can also conduct a "soil shake" test:

• Fill a jar 1/3 full with soil.
• Fill the jar 1/3 full with water.
• Add a tablespoon of alum (alum speeds the settling process and can be found in the spice section of the grocery store.
• Ask the children to predict what will happen when the jar is shaken. 
• Divide the children into groups of 3-4. Ask them to collect soil from outdoors or give them some soil you have collected.
• Tighten the lid and shake for 3 minutes. Make sure all the lumps have broken apart. Tell the children to observe the jar after 30 seconds, 1 minute, 2 minutes and 3 minutes and write down what they observe.
• Have them report their findings to the class. Discuss how the soil separates by particle size and identify the particles int he layers they see. The larger sand particles will be on the bottom, with the silt in the middle and any clay particles on top.

For more fun, investigate what kinds of plants grow best in various kinds of soil.

AgBC's: R is for Roots

Last week we talked about ducks and their wetland habitats. But did you know one of the other important functions of wetlands is that they help to stabilize the soil and hold it in place? This  helps to prevent erosion and trap sediments, which helps to create a rich, fertile habitats for plants and animals. But how do they do this?

The roots of the plants in this interior wetlands in North Carolina help protect the soil.
Photo from the National Oceanic & Atmospheric Administration.

The roots of wetland plants play a critical role in protecting the soil from erosion and keeping it in place. Want to see hands-on for yourself if and how roots hold soil in place? Try this simple experiment. Here's what you'll need:

• 5 radish seeds
• 5 mustard seeds
• 2 glass or plastic contains, about 1-cup volume
• earth/soil free from lumps
• water

Fill both containers roughly 2/3 full of soil. Then plant the radish seeds in one container and the mustard seeds in the other. Cover the seeds very, very lightly with soil. Add 1/4 cup water to each container and place in a sunny area or near a bright light. Make sure the soil stays slightly damp.

After 2 weeks, empty the container with the radish seeds onto some newspaper. Do the same with the mustard seed container. What shape does the soil have? Why? Talk about the impact of this discovery. What would happen to the soil if a fire burned all the plant material from a hillside if there was a heavy rain?

Students will have fun with this simple experiment, and you will, too!

AgBC's: L is for Land

Without land, nothing can grow. No green grass under your feet, no shade from the trees, no flowers in your garden and no food on your table. Ouch! Land is pretty important, huh?


Today's farmers use the latest technology to care for their land and ensure it's fertility is maintained.  After all, 91% of America's farms are considered "small family farms" with even more considered "large family farms." It just makes sense that farmers would want to take care of their livelihoods as well as their homes!

Many times we tend to romanticize "the way things used to be" and imagine that old methods were simpler and better....but that's not necessarily true. Remember all those old-fashioned methods? Remember the dust bowl?

Soils hold natural water and resources for plants and ultimately animals. All the food we eat and the materials we use (like paper, wood and clothing to name a few) depend on soil and land. It's important to understand the importance of land and it's role in the ecosystems and agriculture.

The physical properties of soil affect the type and amount of vegetation that can grow in a given location. The water-holding capacity affects the plants than can survive....some plants need well-drained desert soils while others grow in heavy clay and wetland soils.


Have you ever taken the time to feel and explore the texture of soil? The way it feels? The amount of sand, silt and clay particles in soil all affect the way the soil feels because of of these particles are different sizes. Sand particles are the largest and clay particles are the smallest. Most soils have a mixture of sand, silt and clay.


Here's a fun way to determine the texture of your soil:

1. Take approximately 2 tablespoons of soil and add enough water to moisten it. It should make a ball when squeeze.
2. Using your thumb and forefinger, try to make a "ribbon" of soil.
3. If the soil will not hold together in a ball at all, the soil is sand.
4. If the soil makes a ball but will not make a ribbon, it is loamy sand.
5. If it makes a ribbon less than 1 inch long before breaking, it is loam. If it feels gritty it is a sandy loam. If it is equally gritty and smooth, it is loam. And if it feels smooth, it is silt loam.
6. If the soil makes a ribbon 1-2 inches long before breaking, it is a clay loam. It it feels gritty, it is a sandy clay loam. If it is equally gritty and smooth, it is a clay loam. If it feels smooth, it is a silty clay loam.
7. If the soil forms a ribbon 2 inches of longer before breaking, it is a clay soil. If it feels gritty is is a sandy clay. If it feels equally gritty and smooth, ti is clay. And if it feels smooth it is a silty clay.

Have fun and enjoy getting your hands dirty!


Questions to to think about:

• What kind of soil did you have?
• Why would it be important to know what kind of soil you have?
• What might be some good uses for your type of soil? Poor uses?

These are just some of the questions farmers ask themselves about the land they have and some of the factors they have to consider when making the decisions about what crops to plant on their land.


And it's just about that time of year for spring crops to be going into the ground!


This series is inspired by the book The ABC's of Fruits and Vegetables and Beyond.