# Presentation: 061636

## Horizon Properties

- Take a ped from the top soil horizon.  If the soil is very dry, moisten the face of the profile using a water bottle with a squirt top and then remove a ped to determine consistence.

- Holding it between your thumb and forefinger, gently squeeze the ped until it pops or falls apart.  Record one of the following categories of soil consistence on the data sheet.

- Loose

- Firm

- Friable

- Extremely Firm

- (Repeat this procedure for each horizon in your profile.)

**Horizon Properties**

## Horizon Properties

- Loose: You have trouble picking out a single ped and the structure falls apart before you handle it.*

- Extremely Firm: The ped can’t be crushed with your fingers (you need a hammer!).

- Firm: 	The ped breaks when you apply a good amount of pressure and dents your fingers before it breaks.

- Friable:	The ped breaks with a small amount of pressure.

- * Soils with “single grained” structure **always** have loose consistence.

**Horizon Properties**

## Horizon Properties

- ✦ The way a soil “feels” is called the soil texture.

- ✦ Soil texture depends on the amount of each size of particle in the soil.

- ✦ Sand, silt, and clay are names that describe the size of individual particles in the soil.

- Sand are the largest particles and they feel “**gritty**.”

- Silt are medium sized, and they feel soft, silky or “**floury**.”

- Clay are the smallest sized particles, and they feel “**sticky**” and they are hard to squeeze.

**Horizon Properties**

## Horizon Properties

**Relative Size Comparison of Soil Particles**

- beachball

- frisbee

- Sand
- (feels gritty)

- Silt
- (feels floury)

- (2.00 - 0.05 mm, USDA)
- (2.00 - 0.02 mm, ISSS)

- (0.05 - 0.002 mm, USDA)
- (0.02 - 0.002 mm, ISSS)

- (< 0.002 mm, USDA)
- (< 0.002 mm, ISSS)

**Horizon Properties**

## Horizon Properties

**To Determine Soil Texture**

**Step 1. Start with triangle #1**

- ✦ Test for CLAY first: If the soil is sticky, hard to squeeze, can form a long ribbon or worm without breaking, stains your hands, has a shine when rubbed, call it a CLAY **(using triangle 1)**.

- ✦ If it is like a clay but much softer and not as sticky, call it a CLAY LOAM **(using triangle 1)**.

- ✦ If it is very soft and is not like a clay at all, call it a LOAM **(using triangle 1)**.

**Horizon Properties**

## Horizon Properties

**To Determine Soil Texture**

**Step 2. Use triangle #2**

- ✦ Next try to feel for sand.  If the soil has a “gritty,” sandy feel to it, add the word  SAND (or SANDY) to the classification from triangle 1 **(see triangle 2)**.

- ✦ If you can’t feel any sand, and the soil has a smooth feel (like flour), add the word SILT (or SILTY) **(see triangle 2)**.

- ✦ Record the texture class name of your soil sample.

- ✦ If you can feel “**some**” sand, but not a lot, keep the same classification you had from triangle 1, and don’t change it.

**Horizon Properties**

## Horizon Properties

**Presence of Roots**

**Presence of Rocks**

- Observe and record if there are **none**, **few**, or **many** roots in the horizon.

- Observe and record if there are **none**, **few**, or **many** rocks* in the horizon.

- * 	A rock is defined as being larger than 2 mm in size.

**Horizon Properties**

## Horizon Properties

- Free carbonates are compounds that coat soil particles. They form under certain conditions such as in dry climates where the pH is above 7.  They are also found in some soil profiles that have parent materials made of carbonates (such as limestone).

- This test is performed by squirting vinegar on the soil.  If free carbonates are present, they will “effervesce” or bubble when the vinegar reacts with them.  Record one of the following based on your observation:

- None:	you observe no reaction (the soil has no free carbonates).

- Slight:	you observe a slight amount of bubbling (the soil is coated with some carbonates).

- Strong:	you observe a strong reaction (many bubbles) (the soil has many carbonate coatings present).

**Horizon Properties**