# Presentation: 656491

## We Study Soil Because It’s A(n)

**We Study Soil Because It’s A(n)**

**Great integrator**

- Producer and
- absorber of gases (CO2 and others)

- Medium for plant growth

- Medium of crop production

- Home to organisms
- (plants, animals and others)

- Waste decomposer

*Snapshot* of geologic, climatic,
- biological, and human history

- Source material for construction,
- medicine, art, etc.

- Filter of water and wastes

- Essential natural resource

- Medium of heat and
- water storage

## Hydrologic Cycle

- Water enters the soil, interacts with soil particles and leaves the soil (through evaporation, transpiration or leaching).

## Hydrologic Cycle and the Soil

**Hydrologic Cycle and the Soil**

- Color

- Structure

- Bulk Density

- Texture

- pH

- Temperature

- Moisture

- Horizon
- Depths

- Soil Properties that are part of the hydrologic cycle.

## Soil Forming Factors

**Parent Material**

**Topography**

**(The first four factors over) Time**

**Climate**

**Biota**

**These five factors work together to create a unique soil profile made of layers called horizons.**

## Soil Characterization and Moisture Protocols

- Basic
- Field Characterization
- Bulk Density
- pH
- Soil Moisture*
- Soil Temperature*
- * Taught in conjunction with Atmosphere Protocol Sessions

- Advanced
- Particle Size Distribution
- Particle Density
- Soil Fertility

- Optional
- Soil Infiltration

## Soil Characterization

- Following this protocol, you and your students will:

- 1. Expose the top 1 meter of soil
- 2. Describe the exposed soil profile
- 3. Take samples of each soil horizon
- 4. Prepare soil samples for lab analyses
- 5. Analyze the soil samples in the lab
- 6. Review the data to understand
-    your soil better
- 7. Submit the data to GLOBE

- Grassland soil

## Soil Characterization

- 1. Near the Soil Moisture study site
- 2. Within the Biology study site

- Field measurements are done
- once at each site

- Three replicate samples (and extra samples from each horizon in separate plastic bags) from each horizon are taken and reported one time for each site.

**Soil Characterization**

- Soil Sampling Sites and Strategies

## Characterization and Sampling Options

**Soil Pit**

**Auger**

**Exposed Profile (road cut)**

**Surface Sample**

## Soil Pit Technique

**Soil Pit Technique**

- Arid climate soil in
- New Mexico, USA

- Forest soil in Florida, USA

- First, obtain permission to dig a pit.  Obey any and all safety precautions requested, and ask about power and water lines.

## Soil Profile Comparison

- Forest soil in Florida, USA

- Forest soil in Tallinn, Estonia

- Soil profiles in different geographic regions will be similar if the five soil forming factors act on those soils in the same way.

**Soil Profile Comparison**

## Exposed Profile (Road Cut) Technique

- First, obtain permission to take samples from the road cut, excavation, or other soil profile exposed by others.  Obey any and all safety precautions requested.
- Ask about power and water lines.

- Follow Soil Pit Technique directions.

**Finding and Describing Horizons**

- Expose a fresh soil face by scraping approximately 2cm off of the vertical surface of the soil profile.

## Soil Structure

**With Structure**

- Granular

- Blocky

- Prismatic

- Columnar

- Platy

**Soil Structure**

## Soil Structure (continued)

- Single Grained

- Massive

**Horizon Properties**

**Soil Structure (continued)**

**Without Structure**

- Pencil is 19 cm

- See hands for relative size

## Soil Color

**Horizon Properties**

**Soil Color**

**Munsell Notation**

- Hue

- Value

- Chroma

**Notes:**
1.	Take a ped of soil from each horizon and note on the data sheet whether it is moist, dry or wet.  If it is dry, moisten it slightly with water from your water bottle.

2.	Stand with the sun over your shoulder so that sunlight shines on the color chart and the soil sample you are examining.

3.	Break the ped and compare the color of the inside surface with the soil color chart.

Note: Sometimnes, a soil sample may have more than one color.  Record a maximum of two colors if necessary, and indicate (1) the Main (dominant color) and (2) the Other (sub-dominant color).

## Soil Color (continued)

**Soil Color (continued)**

- 1

- 2

- 3

- 4

**Notes:**
Munsell Notation
The Munsell code below each color in the GLOBE color chart is a universal notation that describes the soils’ color.

The first set of number and letter symbols represents the hue.

Hue represents the position of the color on the color wheel (Y=Yellow, R=Red, G=Green, B=Blue, YR=Yellow Red, RY=Red Yellow).

## Soil Consistence

**Soil Consistence**

- Loose*

- Extremely Firm

- Firm

- Friable

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

## Soil Texture

**Soil Texture**

**Relative Size Comparison of Soil Particles**

- barrel

- plate

- 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)

**Notes:**
✦ 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.

## Soil Texture (continued)

**Soil Texture (continued)**

**To Determine Soil Texture**

## Soil Texture (continued)

**Soil Texture (continued)**

**To Determine Soil Texture**

## Test For Free Carbonates

**Test For Free Carbonates**

- This is **strong** effervescence.

**Notes:**
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).

## Preparing for the Field

- 1.	Fill acid bottle with vinegar
- 2.	Fill squirt bottles with water
- 3.	Make a clinometer (see Land
- 	Cover/Biology Protocol)
- 4.	Collect bulk density containers
- 		a.	find can mass
- 		b.	find can volume by filling 		the can with water, pouring 		the water into a graduated 		cylinder, and reading the 		amount in mL.
- 		c.	label cans
- 		d.	hammer hole in bottom

- Note: If using the auger sampling method, take bulk density samples at the surface of the soil as per the Bulk Density protocol for the Surface Sample technique.