The Soil Physics Laboratory

Last changed: 28 April 2021
A woman is holding large tubes, photo.

At the Soil Physics Laboratory we prepare soil samples and determine their soil physical properties. Many of these properties are fundamental to measure in order to understand how the soil interacts with water, nutrients and vegetation, both for research analyses and practical applications. Soil physical properties are for example important for modelling water balances or estimate nutrient or sediment losses in most types of land use.

We analyze soil physical properties for a range of soils and purposes on agriculture and forest land, meadows, as well as urban/peri-urban land. Please do contact for specific questions and needs.

Types of analyses

Soil samples can be brought or sent to us as loose soil or as undisturbed soil samples, depending on what analyses should be performed. Short descriptions of the methods we use are listed below.

Analysis

Soil samples can be brought or sent to us as loose soil or as undisturbed soil samples, depending on what analyses should be performed. Short descriptions of the methods we use are listed below.

Loose soil in bags, cups, boxes, containers etc

For many of the analyses the original soil sample is first air-dried, grinded and sieved at 2 mm mesh to get the “prepared fine soil sample”.

Soil particle size distribution

The particle size distribution in a soil sample is determined with different methods as related to fraction size. The content of particles larger than 2 mm are determined in the fine soil preparation by dry sieving of the air-dried, grinded sample. For determining the content of particles smaller than 2 mm, a combination of wet sieving (0.06-2 mm) and pipette method (<0.2 mm) is performed with the prepared fine soil. The fractions that can be obtained are: Coarse sand (0.6-2 mm), Medium sand (0.2-0.6 mm), Fine sand (0.06-0.2 mm), Coarse silt (0.02-0.06 mm), Medium silt (0.006-0.02 mm), Fine silt (0.002-0.006 mm) and Clay (< 0.002 mm).

Furthermore, particle sizes in the range from 2 mm to 0.000010 mm (10 nm) can be determined with laser scattering particle size distribution analyzer (partica LA-950 V2 from HORIBA). This analysis is carried out in solvent (water) that allows for measuring dry (soil) and wet (water) samples.

Gravimetric soil water content

Original soil sample is weighed, oven-dried overnight at 105° C and then weighed again. The water content is then calculated from weight before and after oven-drying (percentage by weight).

Loss in ignition and organic matter content

Prepared fine soil sample is oven-dried overnight at 105°C to get rid of water. The sample is subsequently oven-dried at 550°C for 4 hours to get the loss on ignition. The organic matter content is approximated from the loss on ignition with a reduction factor related to clay content.

Wilting point

Prepared fine soil sample is wetted and placed in a pressure plate extractor at 1500 kPa to get the water content remaining at -1500 kPa soil water pressure.

Particle density

Particle density is calculated from the volume displacement of prepared fine soil sample in a flask with ethanol.

Soil core samples in cylinders

At the Soil Physics Laboratory we use cylinders with 5 or 10 cm height, 7.5 cm outer diameter, and 7.2 cm inner diameter to analyze the soil core properties.

Water retention properties

Water retention properties are measured by placing soil cylinder samples in sandbox (-0.05 to -10 kPa), on suction plate (-10 to -60 kPa), and in pressure plate extractor (-60 kPa to -100 kPa).

The last step for the water retention curve is the wilting point in pressure plate extractor (-1500 kPa) using prepared fine soil sample.

Actual field soil water content and dry bulk density

Field water content (percentage by volume) and dry bulk density are obtained by oven-drying the soil cylinder samples at 105°C during 3 days, and base calculations on weight before and after drying and cylinder or soil core volume.

Porosity

Porosity is calculated from dry bulk density and particle density values.

Saturated hydraulic conductivity 

Saturated hydraulic conductivity is estimated by means of a constant head permeameter. Water passes through the water saturated soil cylinder sample at a constant water head, and it is collected in a graduated cylinder at the outlet of the sample. The saturated hydraulic conductivity is then calculated from water head, soil sample length, water temperature and outflow velocity.

Shrinkage

The actual volume of the core sample after drying in the oven at 105°C is measured, and compared with the original cylinder volume.

 

Price list (All prices excluding VAT)

Prices will increase from 1st of January 2020

Loose soil (in bags, cups, boxes, containers, etc)

Soil that has been air dried (<5% water content, max. temp. 35°C) and sieved at 2 mm. Fresh soil requires preparation.

Test
Price (SEK/sample)
Sample preparation (air dry, grind and sieve) 172
Soil Particle Distribution (0-20 mm)* 819
    Loss on ignition
    Pipette method and wet sieving (0-2 mm)
    Gravel content (2-20 mm)*
Gravimetric water content 111
Loss on ignition 131
Wilting point 374
Particle density 303
Soil particle distribution (0-2 mm). Laser analysis in soil samples 819
Soil particle distribution (0-2 mm). Laser analysis in water samples     334

*Bigger fractions can be considered

Soil cylinders 

Soil cylinders with exact volume. Otherwise preparation is required (trim and/or measuring actual volume).

Test

Price (SEK/sample)
Sample preparation (trim and/or measure holes)      90
Water retention properties 202
    1 tension
   Dry bulk density
   + Porosity (Particle density)** + 303
   + Extra tension + 142
   + Actual field water content + 71
Actual field water content 222
  Dry bulk density
Saturated hydraulic conductivity 283
Dry bulk density 152
Shrinkage 91
Porosity** 455
   Dry bulk density
   Particle density
Rent cylinders 5/10 cm height, 7,2 cm diameter 40
Damaged or lost cylinder 546

 ** It is necessary to provide soil cylinders, but also loose soil for the particle density calculations.

Contact

Contact us at soilphysicslab@slu.se

Department of Soil and Environment, Lennart Hjelms väg 9, Uppsala (Rooms A3071 and A3075) 

Delivery address

Department of Soil and Environment
Gerda Nilssons väg 5
756 51  Uppsala, SWEDEN

How to deliver your samples

General information to provide

This information is required in the form to fill before delivering the soil samples:

Contact person (the responsible person of the samples)

Sampling date

Sampling place / Samples origin

Project

Special conditions in the soil (if the soil samples are polluted by for example heavy metals, if the samples are fresh and have to be kept in fridge, etc)

Information for invoice (name, department, project number)

After analyses (Inform about keeping, sending back or discarding samples. If no information is given on this, the samples will be discarded after 6 months of sending the results of the analyses)

List of samples (See instructions in the form)

Samples

Observations:

Pay attention about what type of samples is necessary for your test. In some cases it is necessary both, loose soil and cylinders.

Fill the form that you will find in the website: mark the analyses that will be performed and prepare the samples list. Do not use long names or codes (number codes maximum 6 digits).

  • LOOSE SOIL (in bags, cups, boxes, containers, etc): Soil that has been prepared: air dried (max. 35°C, water content <5%), grinded and sieved at 2 mm, or fresh soil.

OBS: If the samples are not air dried grinded and sieved, the preparation will be done in the laboratory (see the price list).

FRESH SOIL: Send enough soil that for the different analysis according to the list below. Very important: do not send more than 2 kg.

  • SOIL PARTICLE DISTRIBUTION: At least 100 g of prepared soil
  • WATER CONTENT: At least 300 g of fresh soil
  • LOSS ON IGNITION: At least 100 g of prepared soil
  • WILTING POINT: At least 200 g of prepared soil
  • PARTICLE DENSITY: At least 200 g of prepared soil
  • SOIL CYLINDERS: Cylinders can be rented from the Soil Physics Laboratory (5 or 10 cm height, 7.5 cm outer diameter, and 7.2 cm inner diameter).

The cylinders can be rented for short periods to collect undisturbed soil samples or to prepare samples and then to send them back to the laboratory. In the case of non-undisturbed samples, loose soil can be placed in cylinders and repacked to relevant density by the customer). To rent cylinders it is necessary to specify how many cylinders will be rented, for how long (the day to pick up and return), and which analyses that will be performed in the laboratory. It is also necessary to specify the need of sliding hammer or not for sampling, as lids and filter paper (for keeping the soil in the cylinder).

It is also possible to send us your own cylinders. In this case, a fee to handle them (washing etc) will be included. The transport costs to return the cylinders will be covered by the customer. If the weights of the cylinders are not provided, the raw data (cylinder+soil weights) will be sent as results.

  • OBS1: If the samples have to be trimmed and/or have excavations that need to be measured for volume corrections it should be mentioned. Any need of volume correction should be specified in the order.
  • OBS2: Keep rented cylinders in their respective boxes. The boxes should come back to the laboratory with all their respective cylinders.
  • OBS3: Do not write, put stickers  or carve numbers or text on rented cylinders and lids since the cylinders and lids  will be used in other studies (any reference to the original numbers on the cylinders are referred to on separate sheet). Furthermore, such notes on the cylinders may disappear very easily in the transport and further handling.
  • OBS4: If other material is also borrowed/rented together with the cylinders, all the material taken from the Soils Physics Laboratory should be brought back as soon as possible.
  • OBS5: If there will be more than one analysis performed in the samples, it may be more convenient to take different group of samples for the different analyses.

Lab order form (excel-sheet for download)

 


Contact

soilphysicslab@slu.se

Page editor: cajsa.lithell@slu.se