TEKS 4.7ATEKS 4.7AThe student is expected to examine properties of soils, including color and texture, capacity to retain water, and ability to support the growth of plants.

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. SandSandy soils are loose and rainwater drains quickly through these soils.They do not retain, or hold, water very well.

Incorrect Answer Choices:

A. Silty soils retain water rather well. Silt looks like small, fine pieces of mud, and is a fertile soil for plants.

B. Clay particles are small and tightly-packed. Their plate-like shape allows them to hold too much water. This gives clay soils a gummy, sticky texture. Clay is not good for plant growth.

C. Loam holds water rather well and is a very fertile soil for plants.

Loam is fertile soil for plants to grow.

LOAM

Let’s try another question about soils.

Which type of soil enabled this tree to grow properly?

A. ClayB. LoamC. RockyD. Sandy

Correct Answer Choice: B

LoamLoam is nutrient-rich, dark-colored soil that retains water well, but allows just the right amount to drain. For a plant to grow properly, the roots need water and nutrients.

Incorrect Answer Choices:

A.Clay soils retain far too much water for roots. They are nutrient-poor and are so tightly-packed that roots do not have space to grow.

C. Rocky soils are full of rocks and do not retain water well. They do not contain free nutrients for plants.

D.Sandy soils are also nutrient-poor. Particles are round with a lot of space between them, allowing water to run through easily.

Let’s try another question about soils.

The Grapevine Garden Club prefers to container garden in dark soil that is rich in decaying organic matter and drains well. Which of these soil types best fits that description ?

A. Silt 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:

A. Silt is not made entirely of organic matter.

B. Sand is nutrient-poor for plants.D. Clay is nutrient-poor

soil.

Remember: The “texture” of soils is how they feel.

-Sandy soils feel gritty.-Clay soils feel gummy, sticky, and hard when dry.-Loam is loose, but when you pack it together, it sticks.