Soil: What Is in It and Why Plants Need It
Explore soil parts, plant roots, water, air, and nutrients
Soil: What Is in It and Why Plants Need It
Explore soil parts, plant roots, water, air, and nutrients
Science - Grade 2-3
- 1
Name three things that can be found in healthy soil.
Think about what you might see or feel if you scooped up garden soil.
Healthy soil can contain tiny rock pieces, decayed plant and animal matter, water, air, and living things like worms or insects. - 2
A student looks closely at soil and finds sand, small bits of leaves, a tiny worm, and damp spots. What does this tell you about the soil?
This tells me the soil has minerals from rocks, organic matter from leaves, living things, and water. - 3
Why do plant roots grow down into the soil?
Roots are like the part of the plant that drinks and anchors the plant.
Plant roots grow down into the soil to take in water and nutrients and to help hold the plant in place. - 4
Circle the two things plants can get from soil: sunlight, water, nutrients, moonlight.
Plants can get water and nutrients from soil. Plants get sunlight from the Sun, not from soil. - 5
Look at a soil layer diagram. The top layer has dark soil with leaves and roots. Why is this top layer important for plants?
The top layer is where many dead leaves break down and become part of the soil.
The top layer is important because it often has many nutrients, decayed plant matter, water, air, and roots growing in it. - 6
What is humus?
Humus is dark material in soil made from dead plants and animals that have broken down. It adds nutrients to the soil. - 7
A plant in dry soil is wilting. What does the plant probably need, and how does soil help?
Wilting leaves can be a sign that a plant does not have enough water.
The plant probably needs water. Soil helps by holding some water near the roots so the plant can take it in. - 8
Why is air in soil important for plant roots?
Air in soil is important because roots need air to stay healthy and keep growing. - 9
Two pots have bean plants. Pot A has loose, damp soil. Pot B has packed, dry soil. Which plant will probably grow better, and why?
Roots need room, water, and air.
The plant in Pot A will probably grow better because loose, damp soil gives roots water and space for air. - 10
Explain how worms can help soil.
Think about what happens when worms move through dirt.
Worms help soil by making tunnels that let air and water move through the soil. Their waste can also add nutrients. - 11
Which soil would let water pass through faster: sandy soil or clay soil? Explain your answer.
Sandy soil would let water pass through faster because it has larger spaces between its particles than clay soil. - 12
A gardener mixes old leaves into garden soil. How can this help the plants later?
Dead leaves can become part of the soil over time.
The old leaves can break down into humus, which adds nutrients to the soil and helps plants grow. - 13
Fill in the blanks: Soil is made of tiny pieces of blank, bits of dead plants and animals, water, air, and living things.
Soil is made of tiny pieces of rock, bits of dead plants and animals, water, air, and living things. - 14
Look at the picture of a plant. Label one part that gets water from the soil and one part that makes food using sunlight.
Roots are usually under the ground, and leaves are usually above the ground.
The roots get water from the soil, and the leaves make food using sunlight. - 15
Why can very poor soil make it hard for plants to grow?
Very poor soil can make it hard for plants to grow because it may not have enough water, air, nutrients, or space for roots.