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

1. Characterization Laboratory Analysis • Advanced • Particle Size Distribution • Particle Density • Soil Fertility Basic Bulk Density pH Soil Moisture* * Taught in conjunction with Atmosphere Protocol Sessions

2. Laboratory Analysis Particle Size Distribution Relative Size Comparison of Soil Particles

3. Laboratory Analysis Particle-Size Distribution (continued) Clay left in Suspension Settled Silt Settled Sand Soil Mineral Particles Settled in Cylinder Remember Stokes Law: The bigger they are, the faster they fall (in water)!

4. Laboratory Analysis 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

5. 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

6. Laboratory Analysis Particle-Size Distribution (continued) • 25g soil • 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.

7. Laboratory Analysis Particle-Size Distribution (continued) • Shake Cylinder hand over hand 10 times. • Start timing. (e.g. timing starts at 10:05 am) From when you start timing: 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.) 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).

8. Laboratory Analysis Particle-Size Distribution (continued) • Use the Particle Size Distribution protocol worksheet to calculate the percent sand, silt, and clay in your sample • Use the Textural Triangle do determine the soil texture class and compare it to the texture you determined by the field method. Read the percentages on the triangle in the direction that the numbers face. This soil is a sandy clay loam

10. Comparison of Bulk Density and Particle Density

11. In the soil, air and water are found within the pore spaces between the particles. If this ideal soil were dried out, and all the pore space were compressed so that there was no more air and no more space, all that would remain would be the solid portion of the soil. To calculate bulk density, we would measure the mass of the total volume of a soil sample.

12. Laboratory Analysis Particle Density • Weigh out 25g soil and pour distilled water into a squirt bottle. • Weigh empty flask without the cap. • Place 25g of soil into flask (wipe outside of flask clean) and get their mass without the cap.

13. Laboratory Analysis Particle Density (continued) • Using squirt bottle, add approximately 50mL Distilled water into the flask. (Wash any soil on the neck back into the bottom of the flask.) • Bring soil and water mixture to a gentle boil for 10 minutes. During this time, agitate the flask for 10 seconds every minute.

14. Laboratory Analysis Particle Density (continued) • After 10 minutes, remove flask from heat and allow it to cool. Cap flask and let sit for 24 hours. Cap flask and let sit for 24 hours. • At 24 hours, remove cap and add enough Distilled H2O to bring volume to 100mL (the bottom of the meniscus should be at 100mL).

15. Laboratory Analysis Particle Density (continued) • Weigh the soil and water mixture without the cap. • Take temperature reading by placing thermometer into the water in the flask for one minute. (Take out, clean and dry thermometer.) • Calculate the soil particle density using the Soil Particle Density Data Sheet.

16. Laboratory Analysis Soil Fertility Measurements Follow the directions in the GLOBE soil test kit to determine the fertility of the soil (N, P, and K) 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

17. Laboratory Analysis Soil Fertility Measurements Soils that have clay particles and organic matter usually have a negative charge. NO3- Soil in low pH (acidic) conditions K+ PO4-3 Clay Particle NO3- K+ NO3- AlPO4

18. Soil Fertility Measurements (continued) Laboratory Analysis Soils that have clay particles and organic matter usually have a negative charge. NO3- Soil in high pH (basic) conditions K+ PO4-3 Clay Particle NO3- K+ NO3- CaHPO4