TEKS 4.7A Examine properties of soils, including color and texture, capacity to retain water, and ability to support the growth of plants

A. Silt B. Clay C. Loam D. Sand Listed in the diagram below are four types of soils. Select the one that retains the “least” amount of water. A. Silt B. Clay C. Loam D. Sand

Correct Answer Choice: D Sand Sandy soils are loose and rainwater drains quickly through these soils. They do not retain or hold water very well. They have low water retention, which means, water is not held by the sand. It does not stay in it.

Incorrect Answer Choices: Silty soils retain water rather well. Silt looks like small, fine pieces of mud, and is a fertile soil for plants.  Clay-like soils are hard-packed and hold too much water. This is not good for plants to grow because the soil is gummy.  C. Loam holds water rather well and is a very fertile soil for plants. 

Loam is fertile soil for plants to grow. Want to see a picture of loam Loam is fertile soil for plants to grow. Want to see a picture of loam? View next slide!

Picture of loam LOAM

Let’s try another question about soils!

A student added some soil to a glass beaker, then poured 10 mL of water into the same beaker. The water ran completely through the soil, and collected at the bottom of the beaker. The water had tiny light-colored grains in it. Which answer best describes what the water at the bottom of the beaker contained?

What was in the water at the bottom of the beaker? Clay Sand Humus Loam

Correct Answer Choice: B Sand Sandy soils are loose and made of fine small particles. As the water ran through the soil, some of the sand grains went with it.

Incorrect Answer Choices: A. Clay-like soils are hard-packed. They are not like loose particles of sand. C. Humus is topsoil which is just like loam. It is not like loose particles of sand. D. Loam is rich fertile soil and not made of loose particles, like sand.

Sand is made of loose, small particles. You can build sand castles at the beach because the sand is made of small, loose particles.

Let’s try another question about soils!

Which type of soil enabled this tree to grow properly? Clay Loam Rocky Sandy

Correct Answer Choice: B Loam Loam is nutrient-rich black soil that also has good water retention. For a plant to grow properly, the roots need water and nutrients. Loam is good stuff!

Incorrect Answer Choices: Clay soils retain way too much water for roots. Roots can rot in wet, nutrient-poor clay soils.  C. Rocky soils are just that, full of rocks. They do not contain any nutrients for plants.  D. Sandy soils do not hold nutrients. Particles are small, the nutrients run through the sand with the water. 

Let’s try another question about soils!

Suppose there was a seed found in the soil, under the big rock in the picture. What would probably happen to the seed?

The seed would… A. push the big rock out of. the way and start to The seed would… A. push the big rock out of the way and start to grow B. not grow C. be eaten by a wolf D. make more seeds

Correct Answer Choice: B not grow The seed will not grow because the seed and the soil are being crushed by the rock.

Incorrect Answer Choices: The seed is too tiny to exert a force needed to move a big rock. Wolves do not eat seeds under rocks. D. One seed does not make more seeds.

Let’s try another question about soils!

A. Bedrock B. Sand C. Humus D. Clay What is the name of the dark soil that is rich in decaying organic matter? A. Bedrock B. Sand C. Humus D. Clay

Correct Answer Choice: C Humus Humus is a nutrient-rich soil formed by the breakdown or decomposition of dead plants and animals. Plants grow well in humus-rich soils.

Incorrect Answer Choices: Bedrock is not soil, but a layer of rock. B. Sand is nutrient-poor for plants. D. Clay is nutrient-poor soil.

Nutrient-rich soil requires good water retention for plant growth.

Remember: The “texture” of soils is how they feel Remember: The “texture” of soils is how they feel . . . *Sandy soils feel gritty. *Clay-like soils feel gummy, sticky, and hard. *Loam feels just right. It’s loose, but when you pack it together, it sticks.

The End