Growing Plants Hydroponically vs. In Soil:

The Soil Profile

Questions

Why do we need to know what is in the soil?

How do we determine what is in the soil?

Particle Sizes

Soil Structure

Massive

Soil Texture

Soil Texture Triangle Examples

1. 20% Clay, 10% Sand and 70% Silt?2. 30% Clay, 60% Sand, and 10% Silt?3. 55% Clay, 45% Sand?

Identifying Texture by Feel Feel test – Rub some moist soil between your fingers.

• Sand feels gritty.• Silt feels smooth.• Clays feel sticky.

Ball squeeze test – Squeeze a moistened ball of soil in your hand.• Coarse textures (sand or sandy loam) soils break with slight pressure.• Sandy loams and silt loams stay together but change shape easily.• Fine textured (clayey or clayey loam) soils resist breaking.

Ribbon test – Squeeze a moistened ball of soil out between your thumb and fingers.• Sandy soils won’t ribbon.• Loam, silt, silty clay loam or clay loam soil ribbons less than 1 inch.• Sandy clay loam, silty clay loam or clay loam ribbons 1 to 2 inches.• Sandy clay, silty clay, or clay soil ribbons more than 2 inches.A soil with as little as 20 percent clay may behave as a heavy clayey soil. A soil needs 45 percent to over 60 percent sand to behave as a sandy soil.

Dirt Shake

Soil Profile Review

What is Soil Made up of?

http://www.physicalgeography.net/fundamentals/images/soil_breakdown.gif

• Horizon O is the organic matter

• Horizon A is the topsoil

• Horizon B less topsoil and less organic matter

• Horizon C Parent material

• Bedrock below Horizon C

Soil ProfileHorizon O – Organic matter. This layer us usually less than an inch thick. Litter decomposes into nutrients that enrich the soil. In area where the temperature is lower, the composition of organic matter is slower.Horizon A – top layer of soil. Nutrients, bacteria, fungi, and small animals

are abundant. Plant thrive because of the nutrients in it.Horizon B –Light in color because it has less top soil and organic matterHorizon C – Called the parent material because it is the weathered roc and

partly weathered soil from which the soil layers above are formed. Bedrock – solid rock. Parent material is formed from the bedrock after a long

weathering process. Happens either physical or chemical. Physical – wind or water erosion, glacial activity, freezing and thawing

and biotic activity (plant roots, animals, micro-organisms)Chemical – leaching, oxidation, carbonation, and hydration

Soil Color-Munsell Color Chart

Group Rotation

You will have 10 minutes at each one of the stations.

Follow the directions on the sheet or wait for me to come around and give you directions.

Make sure to complete any work that is in your workbook on pages 6-7.