# Presentation: 128328

## Characterization Laboratory Analysis

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

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

## Particle Size Distribution

**Particle Size Distribution**

**Relative Size Comparison of Soil Particles**

- 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)

- 2 min.
- 12 min.

- 24
- hour

- barrel

- plate

## Particle-Size Distribution (continued)

**Settled Sand**

**Settled Silt**

**Clay left in **
**Suspension**

**Soil Mineral Particles Settled in Cylinder**

**Laboratory Analysis**

**	****Remember Stokes Law: The bigger they are, the faster they fall (in water)!**

## Particle-Size Distribution (continued)

**Specific Gravity: The weight of a substance relative to the weight of an equal volume of water.**

- This hydrometer reading is 1.000

**Laboratory Analysis**

## Particle-Size Distribution (continued)

**When soil is added to water, the specific gravity and the hydrometer reading increase.**

- This hydrometer reading is: 1.008

**Laboratory Analysis**

## Particle-Size Distribution (continued)

- 100mL Dispersing Solution
- 50mL Distilled H2O
- Put all three into a 500mL beaker and stir for one minute.
- Cover with plastic wrap and let mixture sit for 24 hours.
- Remove plastic wrap and stir for one minute.
- Measure the distance from base of 500mL cylinder (0mL line) to 500mL line.
- Pour entire soil mixture into 500mL cylinder.
- Fill to 475mL line with distilled H2O and add to 500mL line with distilled H2O from squirt bottle.
- Cover cylinder with plastic wrap.

**Particle-Size Distribution (continued)**

**Laboratory Analysis**

## Particle-Size Distribution (continued)

- From when you start timing:

- Time	Action
- 1 min. 30 sec. 	Put Hydrometer in cylinder.
- 2 min. 	Read hydrometer (remove, rinse and dry hydrometer).
- 2 min. 30 secs.	Put thermometer in cylinder.
- 3 min. 30 secs. 	Take temperature reading (take out, clean and dry thermometer).
- 11 min. 30 sec. 	Put Hydrometer in cylinder.
- 12 min. 	Read hydrometer (remove, rinse and dry hydrometer).
- 12 min. 30 secs. 	Put thermometer in cylinder.
- 13 min. 30 secs. 	Take temperature reading (take out, clean and dry thermometer).

- Sample Time
- (10:06 30 secs.)
- (10:07)
- (10:07 30 secs.)
- (10:08 30 secs.)
- (10:16 30 secs.)
- (10:17)
- (10:17 30 secs.)
- (10:18 30 secs.)

- Start timing. (e.g. timing starts at 10:05 am)

**Particle-Size Distribution (continued)**

**Laboratory Analysis**

## Particle-Size Distribution (continued)

**Laboratory Analysis**

## Soil Fertility Measurements

**Laboratory Analysis**

- Nitrogen (N)
- 	Plants use Nitrogen to make amino acids and proteins.
- Phosphorus (P)
- 	Phosphorus is a source of energy for plant cells.
- Potassium (K)
- 	Plants use Potassium to aid in chlorophyll production and other activities

## NO3-

**NO****3****-**

**PO****4****-3**

**K****+**

**K****+**

**AlPO****4**

**NO****3****-**

**NO****3****-**

- Clay Particle

**Soil Fertility Measurements**

- Soils that have clay particles and organic matter usually have a negative charge.

- Soil in low pH (acidic) conditions

**Laboratory Analysis**

## NO3-

**NO****3****-**

**NO****3****-**

**PO****4****-3**

**K****+**

**K****+**

**CaHPO****4**

- Clay Particle

**Soil Fertility Measurements (continued)**

- Soils that have clay particles and organic matter usually have a negative charge.

- Soil in high pH (basic) conditions

**NO****3****-**

**Laboratory Analysis**

## Soil Science Resources