Pedosphere

General

• Graduated Cylinder: 100 mL
  Glass graduated cylinder with a capacity of 100 mL marked in 1 mL or smaller divisions, with graduations covering at least the range from 10 mL to 100 mL.
   
• Balance & Augers
  The same balance and auger used for Gravimetric and Volumetric Soil Moisture will be used for Bulk Density.
   
• Soil Sample Cans and Other Soil Containers
  Cans and containers should meet the same specifications as given for these items for Gravimetric and Volumetric Soil Moisture.

Sample Preparation

• Sieve
  Number 10 sieve with 2 mm mesh attached to a frame.

Slope

• Clinometer
  A clinometer as described in the Biosphere Investigation. See Investigation Instruments: Clinometer for instructions on making a clinometer.

Soil Profile

• Camera
  A digital camera or a camera with color film. Mobile phone cameras can also be used.
   
• Meter Stick
  A durable ruler with gradations every cm and mm.
   
• Soil Auger
  See soil auger types listed under Soil Moisture.

Color

• Color Chart
  A soil color chart designed especially for The GLOBE Program can be purchased. It contains at least 200 colors and uses the Munsell System of Color Notation. This flip chart is weather-resistant and has large color chips which are edge-mounted for ease of reading. The color range includes all hues found in the full set of International soil colors, yet provides a selected set of values and chroma to aid color identification for students. Manufacturers who wish to prepare another version should contact The GLOBE Program for the complete list of colors.

Free Carbonates

• Vinegar
  Distilled white vinegar. Household vinegar may be used.
   
• Acid Squirt Bottle
  A bottle capable of safely holding at least 200 mL of vinegar (acid) is required.

General

• Soil NPK (Macronutrients) Kit
  The test kit must:
  • Contain unit-dose reagents and containers needed to extract soil nutrients from 50 samples and to perform 50 tests of each: soil nitrogen; soil phosphorus; and soil potassium.
  • Employ methods based on the Spurway extraction method, the zinc reduction/chromotropic acid method for nitrogen, the ascorbic acid reduction method for phosphorus, and the sodium tetraphenylboron (turbidimetric) method for potassium.
  • Contain clear instructions, including diagrams, for using the kit.
  • Contain a water resistant color chart for interpreting the results of colorimetric tests and a turbidity chart for the turbidimetric test.
     

Sample Preparation

• Sieve
  Number 10 sieve with 2 mm mesh attached to a frame.

General

• Dual Ring Infiltrometer
  Two concentric metal cylinders. The inner one must have a diameter of 10 cm to 25 cm. The outer one must have a diameter at least 10 cm larger than the inner cylinder. Both cylinders should be 10 to 15 cm high and open at both ends. Steel cans may be found which will work for this apparatus.

Gravimetric and Volumetric Soil Moisture

• Balance
  This balance must have the capacity to weigh 300 grams with an accuracy of +/- 0.1 gram. It can be either mechanical or electronic. It is assumed that a balance is available locally, for example in a high school science laboratory.
   
• Drying Oven (soils)
  Drying oven capable of holding a temperature of 95 ºC - 105 ºC for at least 10 hours or a temperature of 75 ºC - 95 ºC for 24 hours. The oven must be ventilated, and have interior dimension of at least 25 cm x 30 cm x 25 cm. It is assumed that an oven is available locally, for example in a high school science laboratory.
   
• Soil Sample Cans
  15 round sample tins. A metal container with a diameter 7 cm, and height 5 cm, with a removable cover is appropriate as are small round, cleaned food cans. Cans must be capable of having a small hole punched in their bottoms.
   
• Other Soil Containers
  15 containers large enough to have soil samples transferred into them directly from an auger without loss of sample. Glass jars, plastic food containers with lids, or other containers that can be covered and that can hold the soil samples while they are dried in the drying oven selected.
   
• Dutch Auger For Combination Soils
  Dutch (or Edelman) auger for combination soils with a head having the minimum dimensions of 7 cm wide and 18 cm long. The unit (head and shaft inclusive) should be at least 120 cm long in order to be suitable to dig a hole up to 1m deep. It should be of one piece welded construction.
   
• Dutch Sand Auger
  Auger designed for sandy soils with a head having the minimum dimensions of 7 cm wide and 18 cm long. The unit (head and shaft inclusive) should be at least 120 cm long in order to be suitable to dig a hole up to 1m deep. It should be of one piece welded construction.
   
• Bucket Auger
  Bucket (or Riverside) auger designed for hard and brittle soils with a head having the minimum dimensions of 7 cm wide and 18 cm long. The unit (head and shaft inclusive) should be at least 120 cm long in order to be suitable to dig a hole up to 1m deep. It should be of one piece welded construction.
   

Soil Moisture Sensor (Secondary Skill Level)

• Peat Auger
  Auger designed for peat soils with a head having the minimum dimensions of 7 cm wide and 18 cm long. The unit (head and shaft inclusive) should be at least 120 cm long in order to be suitable to dig a hole up to 1m deep. It should be of one piece welded construction.
   
• Soil Moisture Sensor
  This should be a ceramic block sensor that uses an electrical resistance method for soil water matric potential measurement. One of the best ceramic block sensors is called a Watermark block and is the one recommended for this measurement.
   
• Soil Moisture Meter
  There are two meters that can be used. One is manufactured by Delmhorst and reads 0 to 100 (dry to wet). The other is made by Watermark and reads 0 to 200. Both are acceptable by the GLOBE data entry system.
   
• PVC Piping
  The PVC pipe assists in placing the soil moisture sensors in the ground. It should be 90 cm in length and approximately 2 cm in diameter. Additional PVC piping is required to mark the location of the sensors. These should be 23 cm long with a diameter of approximately 5 cm. Four pieces of this material are required.

General

• 100 mL Erlenmeyer flask
  A heat-resistant Erlenmeyer flask with a cap, capable of holding 100 mL of solution.
   
• Heat Source
  A heat source capable of bringing 100 mL of a water and soil solution to a gentle boil and maintaining this boil for at least 10 minutes.

General

• Hydrometer
  The hydrometer used should meet the following requirements:
  • Calibrated to specific temperature for water and sample (e.g. 15.6 C / 15.6 C
  • Range (specific gravity / no units): 1.0000 - 1.0700
  • Smallest increment (no units): 0.0005
     
• Thermometer
  The calibration thermometer described in Air Temperature under Atmosphere can be used for this measurement.
   
• 500 mL Clear Plastic Graduated Cylinder
  One 500 mL capacity plastic graduated cylinder, marked at least at the 500 mL level. Cylinder must be clear plastic, not frosted plastic and not glass.
   
• Dispersing Solution
  Sodium hexametaphosphate powder or a 10% solution of either sodium hexametaphosphate or a detergent that does not produce suds.
   

Sample Preparation

• Sieve
  Number 10 sieve with 2 mm mesh attached to a frame.

General

• pH Measurement Devices
  The same instruments described in Hydrosphere: Water pH will be used for this measurement.
   
• Graduated Cylinder: 100 mL
  The same instrument as described in Soil (Pedosphere): Bulk Density will be used for this measurement.
   

Sample Preparation

• Sieve
  Number 10 sieve with 2 mm mesh attached to a frame.

General

• Soil Thermometer
  A 11 cm to 20 cm stainless steel probe, heavy-duty construction dial or digital thermometer with a range of at least -10 to 50 degrees C (Celsius scale required) and an accuracy of 1% full scale (over a range of no more than 200 degrees C) or better is required. The sensor should be in the bottom third of the probe. The sensor should give stable readings after less than 60 seconds in an isothermal bath. Batteries, if required, should be included. The sensor should be adjustable with the calibration procedure and achievable accuracy clearly stated. Dial thermometers must be sealed against fogging and be covered with shatterproof glass or plastic. Scale graduations of 1.0 degrees C and 0.1 degrees C are preferred for dial and digital thermometers, respectively. Glass stem thermometers are NOT acceptable.
   
• Digital Maximum and Minimum Thermometers
  See Digital Maximum and Minimum Thermometers listed under Atmosphere: Air Temperature.

General

• 4-Channel Data Logger
  A self contained, programmable data logger capable of collecting and storing data from four temperature sensors (one air, possibly internal, and three soil - external channels). Data logger must be capable of collecting data at 15 and 60 minute intervals (sampling frequency) and storing at least 3750 measurements (time/date stamped) per channel (8kb capability is preferred) in nonvolatile memory. The time accuracy must be ±1 minute per week. The temperature must be recorded with at least 7 bits of resolution. The logger must be powered by a user-replaceable lithium-grade battery, with a continuous use lifetime of one year. It must have operational ranges of -20 to +70 degrees Celsius in a 0 - 95% relative humidity, non-condensing environment.
   
• Data Logger Computer Interface and Software
  Computer interface cables and appropriate software for launching the logger and retrieving the data must be available. The computer interface must be MS WINDOWS compatible. MAC compatibility is desired but not essential. The software must allow the data to be exported as an ASCII text file and should provide some basic graphical display of the data.
   
• Air and Soil Temperature Sensors
  Air temperature can be sensed internally if the response time is less than 15 minutes, otherwise, a short (0.3 meter) cable (and 4th external channel) must be available. The soil temperature sensors must be designed to work for years buried up to 1 meter deep in unsaturated soils. Their cables must be between 3 and 6 meters in length. All sensors and cables must be weather and sun-resistant since they will be deployed outside on a continuous basis. All sensors should have an accuracy of ± 0.5 degrees Celsius (at 20 degrees Celsius) and a range of -30 to +100 degrees Celsius.
   
• Watertight Box
  Instructions for constructing a watertight box are provided in the HOBO Data Logger Protocol.
   
• Desiccant
  100 mL of CaSO4 or other dehydrating agent.
   
• Instrument Shelter
  The Instrument Shelter described in Atmosphere: Air Temperature can be used for this measurement.

General

• Automated Soil Moisture and Temperature Station
  A soil moisture/temperature station must be attached to a weather station with a data logger attached to a computer, and be capable of logging data at 15-minute intervals.  Data entry is simplified if the software for the weather station supports the option to “Export GLOBE Data”. Ideally there will be four soil moisture sensors, three temperature sensors for soil, and one optional temperature sensor for air.  However, you may use fewer sensors.
  
  The sensors used with the soil moisture/temperature station must meet the following specifications:
  • Temperature: sensors must be designed to work for years buried up to 1 meter deep in unsaturated soils. Their cables must be between 3 and 6 meters in length. All sensors and cables must be weather and sun-resistant since they will be deployed outside on a continuous basis. All sensors should have an accuracy of ± 0.5 degrees Celsius (at 20 degrees Celsius) and a range of -30 to +100 degrees Celsius.
  • Soil Moisture: ceramic block sensors that use an electrical resistance method for soil water matric potential measurement. One of the best ceramic block sensors is called a Watermark block and is the one recommended for this measurement.