Frost Tube

Students will construct a Frost Tube that is inserted into a hole in undisturbed and uncompacted soil. During the cold months, students measure the depth at which water in the Frost Tube has frozen, indicating that the surrounding soil has also frozen. Watch the Frost Tube Training Video.

Soil Characterization

Students will use a technique chosen by their teacher to expose a soil profile for characterization.

Students will identify horizons in a soil profile, observe the structure, color, consistence, texture, and the presence of rocks, roots, and carbonates of each horizon, and take samples for use in laboratory characterization protocols.

Soil Fertility

Students will use a GLOBE Soil Fertility Kit to prepare samples and determine whether nitrate, phosphate, and potassium are absent from a soil sample or present in low, medium or high concentrations.

Soil Infiltration

Students will use a dual ring infiltrometer that they can construct from large food container cans to measure the rate at which water soaks into the soil during a roughly 45-minute period.

Soil Moisture - Gravimetric

Students will measure soil water content by comparing the wet and dry masses of samples.

Soil Moisture - SMAP Block Pattern

Students will obtain in situ measurements of soil moisture that are consistent with soil moisture measurements from the Soil Moisture Active Passive (SMAP) satellite.

Soil Particle Density

Students will measure the volume of a known mass of dry soil particles and calculate the density of the particle portion only of a soil sample.

Soil Particle Size Distribution

Students will suspend a known mass of dry soil in water and measure the specific gravity of the suspension after sand and then silt has settled out of the suspension to determine the amount of each soil particle size group in the sample

Soil Temperature

Students install soil moisture sensors and temperature probes and connect them to a Davis Soil Moisture and Temperature Station. Data are logged every 15 minutes and periodically students transfer these data to a computer and report them to GLOBE.

Soil pH

Students will prepare a one-to-one mixture of dry soil and distilled water and then measure the pH of the liquid left after most of the soil has settled to the bottom of the mixture.